[Index]
Monthly Global Tropical Cyclone Summary December 2003
[Summaries and Track Data] [Prepared by Gary Padgett]
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Cyclones
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Monthly Global Tropical Cyclone Summary December 2003 [Summaries and Track Data] [Prepared by Gary Padgett] |
MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY
DECEMBER, 2003
(For general comments about the nature of these summaries, as well as
information on how to download the tabular cyclone track files, see
the Author's Note at the end of this summary.)
*************************************************************************
DECEMBER HIGHLIGHTS
--> Not one, but two, Atlantic tropical storms
--> North Indian cyclone destructive to India
--> Long-lived Southwest Indian cyclone affects Madagascar
--> Northern Australia experiences hurricane strike
--> Strong tropical storm brushes Mauritius
*************************************************************************
***** Feature of the Month for December *****
TROPICAL CYCLONE CLIMATOLOGICAL DATA
for the SOUTH PACIFIC OCEAN
A. Introduction
---------------
This month's feature is the second of three highlighting tropical
cyclone climatological data for the Southern Hemisphere. The source
for the data was a set of tropical cyclone tracks sent to me by Mr.
Charles Neumann. These had been prepared in association with a
hurricane risk analysis (HURISK) study he was performing for the U. S.
Navy. Earlier studies had been accomplished for the Atlantic and North
Pacific basins. The tracks and intensities were based upon available
data sets for the various Southern Hemisphere basins from the regional
warning centers, and from 1980 onward, JTWC's Best Track files were
utilized as an additional source of data.
The data set begins with the 1960-61 Southern Hemisphere cyclone
season and extends through 2001-2002, and I have included the entire
period. While the annual number of intense tropical cyclones
(MSW < 100 kts) increases somewhat around 1970, the numbers of tropical
storms and hurricanes during the pre-1970 period are not significantly
different than for years following the advent of meteorological
satellites. No doubt in pre-satellite years many cyclones were not
detected, especially in the vast island-free South Indian Ocean. But
in some areas, such as northern Australia, where most storms form near
land and affect the coastline, and also in the island-rich South Pacific,
it is likely that most significant tropical cyclones were at least
detected (even if not tracked accurately) before operational satellite
coverage became complete in the late 1960s.
B. Definition of Parameters
---------------------------
The following definitions apply:
NS - a tropical cyclone with a peak 1-min avg MSW >= 34 kts
H - a tropical cyclone with a peak 1-min avg MSW >= 64 kts
IH - a tropical cyclone with a peak 1-min avg MSW >= 96 kts
NSD - four 6-hour periods in which a NS is operating
HD - four 6-hour periods in which a H is operating
IHD - four 6-hour periods in which an IH is operating
NTC - (((Total NS/Avg NS) + (Total H/Avg H) + (Total IH/Avg H) +
(Total NSD/Avg NSD) + (Total HD/Avg HD) +
(Total IHD/Avg IHD))/6) x 100%
I have included another seasonal measure of the overall tropical
cyclone level of activity which I developed--the Tropical Cyclone
Index (TCI). It is a summation of the MSW for each 6-hourly data
point, divided by 100 (kts) with the resultant quotient then squared.
Thus, it is identical to Dr. Bill Gray's Hurricane Destruction Potential
(HDP) except that I begin the TCI with 34 kts, whereas the HDP
calculation begins with 64 kts. It also very similar to the index
which NOAA uses in their Atlantic seasonal forecasts--a summation
of the square of the velocity--except that I've scaled the TCI
to a baseline of 100 kts in order to avoid huge numbers.
My reason for including the TCI is that it is independent of the
period of data covered. The NTC is a good indicator of overall
tropical cyclone activity, but it changes for all years whenever
a new baseline period is utilized, whether this is done on a yearly
basis or every 5 or 10 years. Thus, for example, 1950's NTC for
the 1950-1990 period is not the same as it was for the 1950-2000
period, etc. The TCI correlates very closely with the NTC, however.
I calculated correlation coefficients for the NTC vs TCI data sets
for several basins, and the two indices always correlated to around
97-98%. Thus, the TCI is an absolute index independent of any average
values of the various parameters, yet it correlates well with the NTC
as computed by Dr. Gray's rule.
C. Southern Hemisphere Basins
-----------------------------
Dividing up the Southern Hemisphere tropical cyclogenetical
regions is rather problematic. The Northern Hemisphere basins are
rather neatly divided geographically by landmasses and regions of
very infrequent tropical cyclone formation, but storms form in
the Southern Hemisphere in a rather continuous band from the
Mozambique Channel off the eastern coast of Africa eastward across
the South Indian Ocean, through the seas and gulfs north of
Australia, into the Coral Sea and across the South Pacific to the
region of French Polynesia well east of the International Dateline.
Several different schemes for dividing the Southern Hemisphere into
useful basins for statistical purposes have been proposed, but none
are completely satisfactory in all respects. For my purposes, I am
going to present statistics for various longitudinal regions, some
of which overlap.
This monthly feature focuses on the South Pacific Ocean. Last
month's feature covered the entire Southern Hemisphere and several
portions of the South Indian Ocean. The final one, scheduled for
the February summary, will focus on the Australian Region. Due to
time constraints, I did not calculate the full regime of parameters
for the 2002-2003 season, but I did glean the numbers of NS, H and
IH for the various areas, and these are summarized following each
table. The four regions covered this month are:
(1) Southern Hemisphere east of longitude 135E
(2) Entire South Pacific east of Australia
(3) South Pacific east of longitude 160E (Fiji/New Zealand AOR)
(4) Southeast Pacific (east of Dateline)
Last month's feature included a table for the Southern Hemisphere
west of longitude 135E. Region (1) above is the counterpart of that:
the extreme eastern Arafura Sea, the Gulf of Carpentaria, and the South
Pacific to the western coast of South America, although essentially no
tropical cyclone activity occurs east of longitude 120W. Region (2)
is the open South Pacific east of the Australian continent, while
Region (3) is the area of warning responsibility of the TCWC at Nadi,
Fiji, for cyclones north of latitude 25S, and the Wellington, New
Zealand, office for storms south of 25S. As is the case with longitude
90E in the South Indian Ocean, there is no meteorological reason for
the 160th meridan being a basin boundary--it is strictly arbitrary.
I have included a separate table for the South Pacific east of the
180th meridian (Region 4), even though it is also an arbitrary boundary.
However, tropical cyclone activity east of the International Dateline is
highly variable from year to year, especially east of 160W. That region
only rarely sees tropical cyclones in neutral ENSO or La Nina years, but
can become quite active during El Nino events.
D. Tables of Tropical Cyclone Data
----------------------------------
The tropical cyclone data in tabular format follows. The various
intensity categories are based on a MSW averaged over 1-minute. This
results in slightly higher numbers of cyclones than would be obtained
utilizing a 10-minute averaging period, as all the Southern Hemisphere
TCWCs do. The year listed in the leftmost column is the year in
which the season ends; e.g., 1961 represents the 12-month period from
1 July 1960 through 30 June 1961.
(1) ENTIRE SOUTHERN HEMISPHERE EAST OF 135E
Year NS H IH NSD HD IHD NTC TCI
---------------------------------------------------------------
1961 9 1 0 42.75 3.00 .00 35 32
1962 7 1 0 26.50 .75 .00 24 19
1963 18 2 0 62.00 6.00 .00 63 50
1964 11 4 0 69.25 16.00 .00 76 75
1965 10 3 0 33.50 3.25 .00 41 28
1966 3 1 0 21.75 9.75 .00 28 36
1967 8 2 1 39.75 6.00 1.75 62 43
1968 6 3 0 27.25 2.50 .00 32 26
1969 11 2 0 39.25 3.75 .00 42 36
1970 13 3 0 40.00 4.00 .00 49 36
1971 9 1 0 36.50 1.00 .00 31 30
1972 16 11 5 82.00 30.75 9.00 243 135
1973 14 4 1 41.75 8.00 .75 75 47
1974 15 3 0 49.50 6.75 .00 59 45
1975 13 4 2 62.00 17.25 4.75 129 86
1976 12 5 0 50.25 14.50 .00 72 63
1977 15 4 1 40.25 8.25 .75 77 40
1978 11 4 0 57.00 14.00 .00 69 59
1979 12 4 2 65.25 16.50 4.25 125 84
1980 12 4 1 46.25 6.75 .50 71 50
1981 10 4 0 31.00 6.25 .00 48 33
1982 10 6 5 42.25 16.50 3.00 144 66
1983 15 10 5 95.25 40.25 6.00 235 160
1984 10 6 2 34.50 5.50 1.75 88 55
1985 16 7 5 56.25 18.50 5.75 182 91
1986 10 6 0 38.00 11.25 .00 64 46
1987 16 8 2 63.25 13.50 .50 116 72
1988 7 5 2 40.25 10.00 3.00 96 60
1989 14 6 4 64.75 21.75 6.75 179 110
1990 7 5 1 35.25 11.00 3.50 88 51
1991 4 3 2 27.00 10.25 4.25 88 49
1992 15 9 4 77.75 38.50 10.00 238 164
1993 14 8 5 72.00 32.75 9.50 231 139
1994 6 4 4 38.25 21.00 8.75 162 87
1995 6 3 1 20.00 4.50 1.00 49 26
1996 9 3 1 29.50 4.75 1.25 59 32
1997 17 9 3 95.00 30.25 8.00 213 146
1998 21 12 5 103.00 38.00 10.25 279 186
1999 12 3 1 43.00 12.25 1.75 81 59
2000 9 4 1 23.50 5.50 .50 57 27
2001 8 2 0 19.75 5.25 .00 32 25
2002 8 2 1 16.25 4.75 1.00 48 19
Avg. 11.2 4.6 1.6 47.6 12.9 2.6
2002-2003 Season - NS: 13 H: 7 IH: 6
(2) ENTIRE SOUTH PACIFIC (EAST OF AUSTRALIA)
Year NS H IH NSD HD IHD NTC TCI
---------------------------------------------------------------
1961 9 1 0 42.00 3.00 .00 38 32
1962 6 1 0 24.25 .75 .00 23 17
1963 17 2 0 60.75 6.00 .00 66 49
1964 10 3 0 57.25 15.25 .00 69 65
1965 9 3 0 25.00 3.25 .00 40 24
1966 2 1 0 21.00 9.75 .00 27 36
1967 7 2 1 34.75 6.00 1.75 63 41
1968 5 3 0 25.25 2.50 .00 32 25
1969 10 2 0 37.50 3.75 .00 43 34
1970 13 3 0 39.75 4.00 .00 53 36
1971 7 0 0 31.00 .00 .00 23 23
1972 16 11 5 77.75 30.75 9.00 255 132
1973 12 3 1 38.25 7.75 .75 72 44
1974 15 3 0 47.00 6.75 .00 62 43
1975 12 4 2 60.75 17.25 4.75 135 85
1976 12 5 0 48.50 14.50 .00 76 62
1977 14 3 0 35.25 6.00 .00 55 30
1978 11 4 0 55.00 14.00 .00 72 58
1979 11 3 2 56.50 15.75 4.25 122 76
1980 10 4 1 40.25 6.75 .50 70 45
1981 10 4 0 29.75 6.25 .00 51 32
1982 7 5 4 38.00 15.00 2.75 128 60
1983 15 10 5 95.25 40.25 6.00 248 160
1984 9 4 1 29.50 3.00 .25 58 41
1985 13 6 4 49.50 15.00 4.00 154 76
1986 10 6 0 38.00 11.25 .00 68 46
1987 13 7 2 55.50 13.25 .50 112 66
1988 7 5 2 40.25 10.00 3.00 101 60
1989 14 6 4 64.75 21.75 6.75 189 110
1990 7 4 1 32.50 10.75 3.50 88 49
1991 4 3 2 27.00 10.25 4.25 92 49
1992 15 9 4 76.00 38.50 10.00 251 162
1993 13 8 5 69.50 32.75 9.50 241 137
1994 6 4 4 37.75 21.00 8.75 170 87
1995 5 3 1 17.75 4.50 1.00 50 24
1996 7 2 1 21.75 4.25 1.25 52 26
1997 16 9 3 92.25 30.25 8.00 223 144
1998 18 12 5 97.25 38.00 10.25 287 181
1999 11 3 1 41.75 12.25 1.75 84 59
2000 9 4 1 22.50 5.50 .50 60 26
2001 5 2 0 16.25 5.25 .00 29 23
2002 7 2 1 15.00 4.75 1.00 49 19
Avg. 10.2 4.3 1.5 44.4 12.6 2.5
2002-2003 Season - NS: 11 H: 7 IH: 6
(3) SOUTH PACFIFIC EAST OF 160E (FIJI/NEW ZEALAND AREA)
Year NS H IH NSD HD IHD NTC TCI
---------------------------------------------------------------
1961 8 1 0 29.50 3.00 .00 41 24
1962 6 1 0 22.50 .75 .00 30 16
1963 14 2 0 50.25 5.25 .00 73 40
1964 9 3 0 45.25 12.50 .00 78 52
1965 7 3 0 17.50 3.25 .00 43 18
1966 2 1 0 18.25 9.75 .00 36 33
1967 5 1 0 7.75 .25 .00 19 7
1968 5 3 0 20.00 2.50 .00 39 19
1969 9 2 0 32.50 3.75 .00 51 31
1970 11 2 0 30.00 2.75 .00 52 26
1971 6 0 0 12.50 .00 .00 18 8
1972 11 7 4 36.00 16.75 7.25 226 72
1973 11 3 1 33.25 6.50 .75 86 38
1974 12 2 0 26.25 1.50 .00 49 20
1975 11 4 2 55.50 17.25 4.75 173 80
1976 8 3 0 19.75 4.25 .00 48 21
1977 10 3 0 27.75 6.00 .00 59 26
1978 9 4 0 47.25 14.00 .00 87 53
1979 8 3 1 32.50 6.00 2.25 92 37
1980 9 2 0 25.00 1.00 .00 42 21
1981 9 4 0 22.00 6.25 .00 59 25
1982 6 5 3 23.25 12.00 2.50 134 42
1983 13 9 4 73.00 30.50 3.75 252 118
1984 5 1 0 9.75 .50 .00 20 8
1985 10 5 3 34.75 12.25 3.50 158 58
1986 8 4 0 25.75 7.00 .00 61 29
1987 12 7 2 52.25 13.25 .50 141 64
1988 6 3 2 28.00 9.25 3.00 113 50
1989 13 5 3 52.50 15.75 2.75 173 79
1990 6 2 1 17.00 7.75 3.50 90 34
1991 2 1 1 7.25 3.75 2.25 53 18
1992 13 9 4 61.75 31.75 9.00 296 132
1993 11 7 4 45.00 23.25 7.25 243 98
1994 5 4 3 20.50 10.50 4.00 137 42
1995 4 2 0 8.75 1.00 .00 23 8
1996 4 1 1 13.25 3.75 1.25 51 19
1997 13 8 3 67.25 22.25 6.25 238 102
1998 17 11 5 66.50 30.75 9.00 328 141
1999 10 3 1 36.75 12.25 1.75 105 56
2000 6 4 1 16.00 5.50 .50 67 22
2001 5 2 0 16.25 5.25 .00 37 23
2002 6 2 1 11.00 4.00 1.00 57 16
Avg. 8.5 3.6 1.2 30.9 9.2 1.8
2002-2003 Season - NS: 10 H: 7 IH: 6
(4) SOUTHEAST PACIFIC EAST OF LONGITUDE 180
Year NS H IH NSD HD IHD NTC TCI
---------------------------------------------------------------
1961 3 1 0 11.75 3.00 .00 51 14
1962 3 0 0 6.75 .00 .00 20 4
1963 8 1 0 21.75 4.25 .00 89 21
1964 3 0 0 5.00 .00 .00 18 3
1965 3 2 0 7.25 3.00 .00 55 11
1966 1 1 0 13.50 8.75 .00 72 29
1967 1 0 0 .25 .00 .00 4 0
1968 1 1 0 4.25 .75 .00 23 5
1969 4 1 0 7.50 1.00 .00 40 7
1970 7 2 0 19.50 2.75 .00 86 20
1971 0 0 0 .00 .00 .00 0 0
1972 4 1 0 5.00 .25 .00 33 5
1973 8 0 0 14.75 .00 .00 50 11
1974 6 1 0 8.75 .50 .00 47 6
1975 5 2 1 17.75 6.00 1.75 194 26
1976 3 1 0 7.00 1.75 .00 39 8
1977 7 1 0 12.50 1.50 .00 61 10
1978 5 1 0 29.50 9.25 .00 111 34
1979 3 1 1 8.00 1.00 .50 98 8
1980 6 0 0 8.50 .00 .00 34 6
1981 6 1 0 9.75 1.00 .00 51 8
1982 1 1 1 3.75 2.75 .50 92 8
1983 10 7 3 48.50 22.75 2.50 497 84
1984 1 0 0 2.00 .00 .00 6 1
1985 7 4 0 16.00 3.75 .00 107 19
1986 3 3 0 13.75 5.50 .00 86 18
1987 8 4 1 31.50 8.75 .25 207 42
1988 1 0 0 1.75 .00 .00 6 1
1989 6 2 0 20.50 5.50 .00 96 26
1990 3 2 1 13.50 7.75 3.50 249 30
1991 1 1 1 2.75 1.50 .50 85 6
1992 9 3 2 31.25 12.75 4.50 407 59
1993 7 4 0 15.75 4.25 .00 109 20
1994 1 1 0 1.00 .25 .00 16 1
1995 2 1 0 3.50 .50 .00 25 3
1996 2 0 0 3.00 .00 .00 11 2
1997 7 3 1 28.50 4.75 1.00 196 32
1998 11 7 2 36.00 14.75 4.00 455 69
1999 4 1 0 12.00 3.50 .00 57 15
2000 5 3 1 9.50 4.00 .50 142 15
2001 3 1 0 7.00 1.50 .00 38 8
2002 2 1 1 4.50 3.25 1.00 116 11
Avg. 4.3 1.6 0.4 12.5 3.6 0.5
2002-2003 Season - NS: 6 H: 3 IH: 3
E. Monthly Tropical Cyclone Information
---------------------------------------
I did not have the time to attempt to ferret out monthly information
regarding tropical cyclone genesis. Patrick Hoareau has already
compiled much information on Southern Hemisphere tropical cyclones,
including monthly tropical cyclone frequencies, and this can be accessed
at the following link:
http://australiasevereweather.com/cyclones/stats.htm>
I would encourage those interested in detailed statistics of Southern
Hemisphere tropical cyclones to visit the above website. More infor-
mation describing Patrick's work can be found in the monthly feature
in the February, 2003, summary.
*************************************************************************
ACTIVITY BY BASINS
ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico
Activity for December: 2 tropical storms
Sources of Information
----------------------
Most of the information presented below was obtained from the
various tropical cyclone products issued by the Tropical Prediction
Center/National Hurricane Center (TPC/NHC) in Miami, Florida:
discussions, public advisories, forecast/advisories, tropical weather
outlooks, special tropical disturbance statements, etc. Some
additional information may have been gleaned from the monthly
summaries prepared by the hurricane specialists and available on
TPC/NHC's website. All references to sustained winds imply a
1-minute averaging period unless otherwise noted.
Atlantic Tropical Activity for December
---------------------------------------
Disturbed weather which had developed in the southwestern Caribbean
Sea during the final days of November persisted into the first week of
December. The area began to show signs of organization on the 3rd, and
early on the 4th was upgraded to Tropical Depression 20. By late after-
noon Tropical Storm Odette had been christened, becoming the first named
Atlantic tropical cyclone to develop in December in 19 years. The last
year to see a December tropical cyclone in the Atlantic basin was 1984,
when Hurricane Lili evolved out of a subtropical storm in the central
Atlantic and briefly threatened the Leeward Islands as it moved south-
westward before dissipating. Odette subsequently moved northeastward,
crossing the island of Hispaniola before becoming extratropical on the
7th.
At the same time a non-tropical LOW in the eastern Atlantic was slowly
assuming subtropical characteristics. This LOW was later determined to
have developed into a subtropical storm on the 7th, and by the 9th had
developed full tropical characteristics and was named Tropical Storm
Peter. Peter peaked near hurricane intensity later that day and then
weakened quickly as it moved northward into a more hostile environment.
The most significant thing about Peter was the fact that it developed
at all. Atlantic tropical cyclones in December are about as scarce as
hens' teeth; for two to form in one month is extremely rare. The
last time on record that this happened was in 1887. Also, the two
December storms along with Tropical Storm Ana in April represent the
first occasion since 1887 that three tropical storms or hurricanes have
formed outside the official 1 June-30 November tropical cyclone season.
The last time there were even two out-of-season storms was in 1953, when
Tropical Storm Alice formed in the southwestern Caribbean in late May
and an unnamed tropical storm was charted northeast of the Leeward
Islands in early December.
Finally, a gale center in the central Atlantic on 26 and 27 December
looked for a time as if it might make an attempt to become Tropical
Storm Rose, but it didn't get very far before it sheared off. According
to David Roth, OPC ceased to treat is as an occluded cyclone on the
21st, so possibly the system had some very weak subtropical features.
David indicated that there'd been one 35-kt ship report with several
more of 30 kts.
The official storm reports for Odette and Peter are already available
online on TPC/NHC's website, so only brief summaries of the cyclones are
included here. Links to the official reports are included with each
storm's summary.
TROPICAL STORM ODETTE
(TC-20)
4 - 9 December
-----------------------------------------
Tropical Storm Odette was the first Atlantic named storm to form
in the month of December since 1984, and was the first December storm
on record to develop in the Caribbean Sea. Odette formed in the
southwestern Caribbean and moved generally in a northeastward direction,
crossing the Dominican Republic early on 7 December. After emerging
into the Atlantic the tropical cyclone was soon overtaken by a cold
front and lost its tropical characteristics.
Press reports indicate that substantial damage was sustained by many
farms, crops, electrical lines, roads and bridges. About 35% of the
banana crop was destroyed. The dwellings of 859 families were damaged,
of which 34 were completely destroyed. Damage was also reported in the
capital city of Santo Domingo. An estimated 10,000 persons were
adversely affected by Odette. Eight deaths were directly attributed to
the storm, and two additional persons died of heart attacks indirectly
related to Odette.
The official TPC/NHC report on Tropical Storm Odette, authored by
James Franklin, can be accessed at the following link:
http://www.nhc.noaa.gov/2003odette.shtml?>
(This brief report written by Gary Padgett)
TROPICAL STORM PETER
(TC-21)
2 - 11 December
----------------------------------------
During early December a large extratropical LOW moved over the
eastern North Atlantic Ocean near 20N, 37W. This LOW gradually acquired
persistent deep convection and was classified as Tropical Storm Peter
on 9 December. Movement had been biased toward the south towards warmer
waters during the previous couple of days, which aided in development.
The MSW soon reached 60 kts, and visible satellite images revealed a
banding-type eye and several curved bands associated with Peter around
midday on 9 December. Based on that evidence, Peter possibly may have
been a hurricane but only for a brief period. Thereafter, the storm
quickly deteriorated as it moved northward ahead of a frontal system,
although it managed to keep its identity until the 11th when it was
absorbed into the advancing front. (It should be noted that in post-
storm analysis it was decided not to upgrade Peter to hurricane status.)
The official TPC/NHC storm report on Tropical Storm Peter, written
by Lixion Avila, is available at the following link:
http://www.nhc.noaa.gov/2003peter.shtml?>
(This brief report written by Kevin Boyle)
*************************************************************************
NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180
Activity for December: No tropical cyclones
*************************************************************************
NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180
Activity for December: 1 tropical depression **
1 tropical storm ++
** - classified as a tropical depression by JMA only
++ - classified as a tropical storm by JTWC only
Sources of Information
----------------------
Most of the information presented below is based upon tropical
cyclone warnings and significant tropical weather outlooks issued
by the Joint Typhoon Warning Center of the U. S. Air Force and
Navy (JTWC), located at Pearl Harbor, Hawaii. In the companion
tropical cyclone tracks file, I normally annotate track coordinates
from some of the various Asian warning centers when their center
positions differ from JTWC's by usually 40-50 nm or more. All
references to sustained winds imply a 1-minute averaging period
unless otherwise noted.
Michael V. Padua of Naga City in the Philippines, owner of the
Typhoon 2000 website, normally sends me cyclone tracks based upon
warnings issued by the Japanese Meteorological Agency (JMA) and the
Philippines' Atmospheric, Geophysical & Astronomical Services
Administration (PAGASA). A very special thanks to Michael for the
assistance he so reliably provides.
In the title line for each storm I have referenced all the cyclone
names/numbers I have available: JTWC's depression number, the
JMA-assigned name (if any), JMA's tropical storm numeric designator,
and PAGASA's name for systems forming in or passing through their
area of warning responsibility.
Northwest Pacific Tropical Activity for December
------------------------------------------------
The month of December was fairly quiet in Western North Pacific
waters. One tropical system required warnings from JTWC and was
upgraded to a minimal tropical storm by that agency, but was not named
by JMA. Apparently, JTWC was the only warning center to classify it as
a tropical storm. A report on Tropical Storm 27W (named Zigzag by
PAGASA), written by Kevin Boyle follows--a special thanks to Kevin for
writing the report.
The only other system to be classified as a tropical depression during
December was a weak LOW around mid-month in the South China Sea east of
extreme southern Vietnam. Apparently JMA was the only agency to refer
to this disturbance as a depression. The LOW remained quasi-stationary
on 16-17 December and then weakened. No track was included for this
system in the December tropical cyclone tracks file.
UPDATE TO THE NOVEMBER SUMMARY
------------------------------
After posting the November summary I discovered some information on
the Relief Web's internet site regarding damage caused by Typhoon Lupit
on some of the islands in the Federated States of Micronesia. The
storm passed fairly near some of the islands and atolls in Yap State,
and huge waves and strong winds caused significant damage on three
islands, although fortunately there was no loss of life reported. The
islands affected most severely were Ulithi Atoll, Woleai Atoll, and Fais
Island. On these islands sources of potable water were contaminated by
salt water, and severe damage was sustained to most agricultural crops,
with taro, breadfruit, banana and coconut being the most important.
After the typhoon's passage the islands were in great need of drinking
water, food, and tools with which to repair buildings and for use in
planting new crops.
More information can be found at the following link:
http://www.reliefweb.int/w/rwb.nsf/vLND>
TROPICAL STORM
(TC-27W / ZIGZAG)
24 - 27 December
-------------------------------------
Zigzag: PAGASA name, means to take a meandering path in abrupt
side-to-side movements
A. Storm Origins
----------------
At 0600 UTC on 21 December an area of disturbed weather developed
approximately 140 nm west-southwest of Chuuk Island. Enhanced infrared
satellite animations revealed cycling deep convection organising over a
possible LLCC. The first STWO issued by JTWC at this time assessed a
fair development potential, but little development was noted and the
LLCC remained rather difficult to follow over the next few days. The
potential for development was lowered to poor at 22/0600 UTC and remained
so through the 23rd. It was not raised to fair again until 24/0030
UTC. This was based on an increase in deep convection over a partially-
exposed LLCC. A TCFA was released soon after at 24/0230 UTC, followed
by the first warning on Tropical Depression 27W at 24/0600 UTC.
The partially-exposed LLCC was situated approximately 265 nm north-
northwest of Yap at the time of the first warning with a mid-level ridge
to the northeast of Tropical Depression 27W guiding the system west-
northwestward at 11 kts. At 25/0000 UTC the LLCC was fully-exposed and
the nearest deep convection was located 67 nm to the southeast. As the
day progressed, however, the tropical depression got its act together
as deep convection began to wrap into the LLCC, and the system
accordingly began to intensify. The MSW reached 35 kts, resulting in
the upgrade to tropical storm status at 25/1200 UTC. This was to be its
peak intensity. (JMA never upgraded this system to tropical storm
status, hence, no name was assigned from the international list of
names.)
B. Storm History
----------------
By 0000 UTC 26 December, Tropical Storm 27W was moving slowly west-
southwestward at 5 kts, some 445 nm east of Manila, Philippines. The
west-southwesterly motion was the result of interaction with the north-
east monsoon, and surges in the monsoon flow were to influence the storm
for the rest of its short existence. The LLCC once again became exposed
and deep convection became rather limited, resulting in a downgrade to
tropical depression status at 26/1200 UTC. However, JTWC upped the MSW
back to 35 kts again six hours later.
Tropical Storm 27W subsequently began to move a little more quickly
towards the south-southwest and was located 145 nm north-northeast of
Dapa, Philippines, at 0000 UTC on 27 December. Visible satellite
imagery revealed a partially-exposed LLCC with deep convection located
mostly in the northwest quadrant. Turning southward the system began
to weaken: the LLCC was fully-exposed and deep convection began to
diminish. In a way, PAGASA's name for the system (Zigzag) was very apt
for this tropical cyclone. Tropical Storm 27W/Zigzag continued its
suicide run into the central Philippines and was downgraded to a tropical
depression at 27/1200 UTC. It then turned southwestward, completing
the last part of its zigzag path before dissipating over the central
Philippines at 27/1800 UTC, which was the time of the final warning
issued by JTWC.
C. Damage and Casualties
------------------------
No reports of damage or casualties were received. Tropical Storm
27W/Zigzag made landfall in the central Philippines only a week after
heavy rainfall and mudslides had affected the area, resulting in
destruction of properties and several casualties. Heavy rains from
the cyclone only served to aggravate the problem.
(Report written by Kevin Boyle)
*************************************************************************
NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea
Activity for December: 1 tropical cyclone of storm intensity
Sources of Information
----------------------
Most of the information presented below is based upon tropical
cyclone warnings and significant tropical weather outlooks issued
by the Joint Typhoon Warning Center of the U. S. Air Force and
Navy (JTWC), located at Pearl Harbor, Hawaii. Occasionally some
information may be gleaned from the daily tropical weather outlooks
and other bulletins issued by the Indian Meteorological Department
(IMD), which is the World Meteorological Organization's Regional
Specialised Meteorological Centre (RSMC) for the basin.
The reported maximum sustained winds (MSW) are based on a 1-minute
averaging period, which is used by all U. S. civilian and military
weather services for tropical cyclone warnings. For synoptic
observations in the North Indian Ocean region, both 10-minute and
3-minute average winds are employed, but IMD makes no attempt to
modify the Dvorak scale for estimating tropical cyclone intensity;
hence, a 1-minute average MSW is implied. In the North Indian Ocean
basin JTWC usually does not initiate warnings until a system has
become well-organized and likely to attain tropical storm status
within 48 hours.
TROPICAL CYCLONE
(TC-03B)
12 - 15 December
------------------------------------
A. Storm Origins
----------------
An area of convection associated with a broad low-level circulation
developed very deep in the tropics about 400 nm west of northern
Sumatra on 10 December. A surface analysis and microwave imagery
indicated that multiple LLCCs were embedded within a broad trough which
was being enhanced by strong equatorial westerlies and northeasterly
monsoon flow to the north. Animated visible imagery indicated cycling
and disorganized convection near the trough, while an upper-level
analysis indicated the disturbance lay under favorable diffluence but
under not-so-favorable vertical shear. At 10/1800 UTC the system was
located about 660 nm east-southeast of Colombo, Sri Lanka, with little
change in organization noted.
The development potential was upgraded to fair at 0600 UTC on the 11th
based on improving organization and a weakening of the vertical shear.
A TCFA was issued at 1400 UTC on 12 December, relocating the system to
a position about 530 nm east-northeast of Colombo. Animated enhanced
infrared and microwave imagery revealed that the LLCC had consolidated
to the north of the previous position. The overall organization of the
system had continued to improve and the MSW was estimated at around
25-30 kts. JTWC issued the first warning on Tropical Cyclone 03B at
12/1800 UTC, placing the center approximately 550 nm east-southeast of
Madras, India. Animated water vapor imagery indicated increasing pole-
ward outflow, and the initial warning intensity was estimated at 30 kts.
TC-03B was tracking northwestward at 7 kts along the southern periphery
of a mid-level ridge located to the north of the system.
B. Storm History
----------------
The system continued tracking slowly in a general northwesterly
direction. The LLCC, completely exposed southeast of the deep convection
at 0600 UTC on the 13th, had partially moved underneath the convection
by 1800 UTC. With CI estimates at 35 kts, JTWC upped the MSW to that
value and placed the center of TC-03B about 415 nm east-southeast of
Madras. The cyclone was forecast to continue tracking northwestward
along the southern periphery of a mid-level ridge located to the north-
northeast. The system appeared to be slightly stronger on the 14th--the
MSW was upped to 45 kts at 0600 UTC. By 1800 UTC the center of TC-03B
had reached a position approximately 200 nm east-southeast of Madras.
Animated water vapor imagery indicated good radial outflow with an
additional poleward outflow channel that was being enhanced by the
leading edge of a trough approaching from the west.
By 0600 UTC on 15 December the cyclone had accelerated somewhat in
its northwesterly trek to 14 kts and was located about 130 nm north-
northeast of Madras. Satellite CI estimates ranged from 45 to 65 kts,
and JTWC increased the MSW to its peak value of 55 kts. The center of
TC-03B made landfall at approximately 15/1430 UTC near False Divi Point,
India, and by 1800 UTC was inland and tracking northward at 9 kts.
Convection had decreased significantly since landfall and continued
weakening was forecast. The 1800 UTC warning was the final one from
JTWC. The only observation I've received was sent by Patrick Hoareau.
At 1500 UTC, Machilipatnam (16.2N, 81.2E) reported a pressure of 997 mb
and northeast winds of 40 kts with moderate rain.
C. Damage and Casualties
------------------------
According to press reports, Tropical Cyclone 03B packed quite a
wallop when it struck India. Eleven persons were killed, and three
fishermen who went to sea before the cyclone hit were missing. The
storm triggered heavy rains and flooding, destroying houses in several
villages across four coastal districts in Andhra Pradesh State. Many
trees were uprooted and the cyclone destroyed many banana fields.
There was one report of waves up to 10 metres in height. Television
coverage of the storm's aftermath revealed many fairly thick trees and
poles snapped in two. This would suggest that TC-03B may have been
somewhat stronger than the 55-60 kts reported in the warnings. One
press report mentioned winds of hurricane force, but it is unknown
if this is estimated or recorded, nor whether it refers to sustained
winds or peak gusts. Microwave and scatterometer data suggest that
winds could have been in the 75-80 kt range at landfall.
(Report written by Gary Padgett)
*************************************************************************
SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E
Activity for December: 1 severe tropical storm
1 tropical cyclone (hurricane)
Sources of Information
----------------------
The primary sources of tracking and intensity information for
Southwest Indian Ocean tropical cyclones are the warnings issued by
the Tropical Cyclone Warning Centre on La Reunion Island, part of
Meteo France (MFR), and the Regional Specialised Meteorological Centre
for the basin. However, tropical cyclones in this region are named
by the sub-regional warning centres on Mauritius and Madagascar with
longitude 55E being the demarcation line between their respective
areas of warning responsibility. The La Reunion centre only advises
these agencies regarding the intensity of tropical systems. References
to sustained winds imply a 10-minute averaging period unless otherwise
stated.
In the companion tropical cyclone tracks file, I occasionally
annotate positions from warnings issued by the Joint Typhoon Warning
Center (JTWC) of the U. S. Air Force and Navy, located at Pearl
Harbor, Hawaii, when they differ from MFR's coordinates by usually
40-50 nm or more. The JTWC warnings are also the source of the
1-minute average maximum sustained wind values included in the
tracks file. Additionally, information describing details of
satellite imagery and atmospheric circulation features included in
the narratives is often gleaned from the JTWC warnings.
Southwest Indian Ocean Tropical Activity for December
-----------------------------------------------------
Two tropical storms formed in the South Indian Ocean west of longitude
90E during December with one reaching minimal cyclone (hurricane)
intensity. Tropical Storm Cela crossed the northern tip of Madagascar,
weakened over land, and then emerged into the Mozambique Channel where
it re-intensified. Cela moved slowly and very erratically southward
through the Channel, reaching cyclone strength twice during its long
life. Severe Tropical Storm Darius formed farther east and moved on a
poleward course which took the center very near Mauritius on 2 January
2004. Reports for both these storms follow.
TROPICAL CYCLONE CELA
(MFR-03 / TC-03S)
5 - 21 December
-----------------------------------------
Cela: contributed by Swaziland
A. Storm Origins
----------------
The beginnings of long-lived Tropical Cyclone Cela can be traced to
an area of convection which developed on 3 December about 440 nm west-
southwest of Diego Garcia. Animated enhanced infrared and microwave
imagery revealed cycling and disorganized deep convection associated
with a partially-exposed LLCC to the northwest. A 200-mb analysis
indicated moderate diffluence over the area with weak vertical shear.
By 1800 UTC on the 4th the disturbance had moved westward to a position
approximately 490 nm west-southwest of Diego Garcia. The LLCC was no
longer exposed, and was becoming better organized with improving poleward
outflow. JTWC raised the potential for development to fair at this
time. A TCFA was issued by JTWC at 04/2300 UTC, placing the LLCC about
580 nm west-southwest of Diego Garcia. The LLCC had continued to
organize, and deep convection had increased and was no longer cyclic.
Upper-level conditions remained optimal for further intensification.
MFR issued the first bulletin on the system at 0600 UTC on 5 December,
upgrading it directly to Tropical Depression 03 with 30-kt winds. The
first JTWC warning on TC-03S was issued at 05/1800 UTC, locating the
center about 700 nm west-southwest of Diego Garcia and tracking west-
southwestward at 4 kts. The MSW (1-min avg) was estimated at 30 kts,
and the system was forecast to intensify as the poleward outflow was
being enhanced by the approach of a major shortwave trough from the
southwest. The depression was being steered by a low to mid-level
ridge anchored to the southeast. Intensification of the system was
rather slow, possibly hindered by dry air in the western semicircle.
The track was initially toward the west-southwest, becoming more
westerly on the 7th. At 1800 UTC the system was centered approximately
400 nm north of Mauritius. Convection had been gradually increasing
near the center, and a 07/1733 UTC SSM/I pass depicted deep convection
over the LLCC. MFR and Mauritius were still treating the system as a
tropical depression, but JTWC upped the MSW (1-min avg) to 35 kts at
07/0600 UTC and to 40 kts at 1800 UTC. Satellite CI estimates (1-min
avg) were up to 45 kts, and QuikScat data revealed an unflagged 35-kt
wind vector.
B. Storm History
----------------
Tropical Storm Cela was christened at 0600 UTC on 8 December when the
center was located approximately 285 nm east of the northern tip of
Madagascar, moving westward at 10 kts. Poleward outflow was good, but
deep convection had weakened some during the previous 12 hours. Based on
MFR's warnings, Cela reached an initial peak intensity of 45 kts (10-min
avg) at 0000 UTC on 9 December before weakening slightly. Convection
continued to cycle in intensity up to the time Cela made landfall in
extreme northern Madagascar around 1200 UTC on the 9th. The storm's
intensity at the time of landfall was around 35-40 kts (per MFR), and
by 1800 UTC Cela had been reduced to depression status. Cela quickly
crossed over the northern end of Madagascar and by 0600 UTC on the 10th
was over water once more approximately 50 nm west of the island. The
concurrent JTWC warning indicated that the LLCC was no longer evident
in a surface analysis and QuikScat data, so the 0600 UTC warning was
intended to be the final one. However, by 1800 UTC deep convection was
beginning to regenerate over the old LLCC, so warnings were re-initiated.
Cela's center was then estimated to be about 270 nm north-northwest of
Antananarivo, Madagascar, moving west-southwestward at 11 kts. The
upper-level environment was favorable for further strengthening with
good diffluence and weak vertical shear. The MSW (1-min avg) was
estimated at 25 kts, but this was bumped to 35 kts at 11/0600 UTC.
Interestingly, MFR issued a "final" bulletin on the system at 10/1800
UTC, the same time at which JTWC restarted warnings. However, MFR
also resumed issuing bulletins on Cela at 11/1200 UTC.
Cela remained quasi-stationary on the 11th. Deep convection continued
to slowly increase with both poleward and equatorward outflow evident.
The system was forecast to track slowly poleward along the western
periphery of a low-level ridge to the east. JTWC upped the MSW (1-min
avg) to 40 kts at 11/1800 UTC, based on CI estimates of 30 and 45 kts,
but MFR maintained the system at 25 kts through the 13th. Cela continued
to remain quasi-stationary roughly 300 nm northwest of Antananarivo all
through the 12th and 13th of December while convection cycled in
a diurnal fashion. One CI estimate reached 55 kts on the 12th, but this
came down on the 13th. MFR's intensity remained locked in at 25 kts
through 0000 UTC on 14 December, and JTWC reduced their MSW to 35 kts
at 12/1800 UTC where it remained pegged until 1800 UTC on the 15th.
At 0000 UTC on 14 December MFR increased the intensity to 30 kts, and
at 1200 UTC re-upgraded Cela to tropical storm status. The storm moved
slowly south-southwestward in the Mozambique Channel about halfway
between Madagascar and Mozambique, although late on the 15th a slight
jog to the south-southeast was taken. The intensity remained basically
static, as per both MFR and JTWC, but on the 15th Cela began to show
signs of intensification. At 15/1200 UTC MFR increased the MSW from
35 kts to 50 kts. A microwave pass indicated a mid-level eye feature
with a banding feature wrapping around the southern semicircle. A
transient shortwave trough was enhancing the poleward outflow, leading to
the intensification of Cela. Satellite CI estimates at 15/0600 UTC were
55 and 65 kts, and a SSM/I 37-GHz image revealed an 18-nm irregular eye.
JTWC upped the MSW (1-min avg) to 65 kts at 0600 UTC, and MFR upgraded
Cela to a tropical cyclone (hurricane) six hours later. The system
retained its eye through the 16th, but by 17/0600 UTC an AMSU pass revealed
that the LLCC had become fully-exposed with disorganized deep convection
occurring only in the southern quadrants. Both MFR and JTWC lowered the
intensity to 55 kts at 17/0600 UTC with the storm located approximately
370 nm west-southwest of Antananarivo, moving west-southwestward at
4 kts.
Cela was forecast to slowly decrease in intensity as it tracked
southwestward along the northern edge of a transient HIGH located to
the south. However, another shortwave trough approaching from the
southwest was expected to enhance the poleward outflow once more, leading
to another round of intensification. This forecast verified rather well.
Cela continued to drift southwestward through 0600 UTC on the 18th, when
it became quasi-stationary for around six hours or so at a point about
250 nm west of Tulear on the southwestern coast of Madagascar. Following
this halt the storm began a slow but steady east-southeasterly drift in
the general direction of the southern tip of Madagascar. MFR upped the
intensity to 60 kts at 17/1800 UTC, and to 65 kts for a 24-hour period
beginning at 0600 UTC on 18 December. (It is interesting to note that
at 18/0600 UTC, CI estimates ranged from 45 to 77 kts.) MFR downgraded
Cela to a 60-kt severe tropical storm at 19/0600 UTC, but interestingly,
JTWC upgraded the storm to 65 kts for a 24-hour period beginning at
19/1800 UTC--after MFR had downgraded Cela.
The southeasterly motion came to a halt at 19/1800 UTC when Cela was
centered approximately 175 nm south-southwest of Tulear, or west of the
southern tip of Madagascar. Tropical Cyclone Cela's track southward
through the Mozambique Channel had been very erratic. A late December
tropical storm in the Northwest Pacific basin was dubbed "Zigzag" by
PAGASA; indeed, such a moniker would have been very apt for Cela, based
on the nature of its track. However, after 19/1800 UTC all the
zigzagging ceased. The storm embarked on a definite southerly course,
and by 1800 UTC on the 20th was zipping southward at 20 kts. This rapid
southward motion, however, brought about the demise of this long-lived
and tenacious cyclone as the system moved into an environment of cooler
SSTs and increasing vertical shear. By 20/1800 UTC Cela was beginning
to undergo extratropical transition and the intensity had fallen to
50 kts (per both MFR and JTWC). The storm was well on its way to
becoming fully extratropical at 21/0600 UTC as it continued speeding
southeastward into higher latitudes. JTWC issued their final warning
on the system at this time, and MFR issued their final bulletin at 1200
UTC, placing the 40-kt extratropical gale about 900 nm east-southeast
of Durban, South Africa.
C. Casualties and Damage
------------------------
No reports of casualties or damage resulting from Tropical Cyclone
Cela have been received.
(Report written by Gary Padgett)
TROPICAL STORM DARIUS
(MFR-04 / TC-06S)
29 December - 4 January
-------------------------------------------
Darius: contributed by Mauritius
A. Storm Origins
----------------
On 24 December an area of convection was noted approximately 325 nm
west of Diego Garcia. The existence of a LLCC was suspected within the
near-equatorial trough, and an upper-level analysis indicated weak
vertical shear and good divergence aloft. The zone of disturbed
weather was very broad, and on the 25th the primary area of interest
was relocated much farther to the east to a point approximately 170 nm
west-northwest of Diego Garcia. A 25/1248 UTC QuikScat pass indicated
cross equatorial flow but no clear evidence of a LLCC. Over the next
couple of days there was little change in the system--convection
continued to cycle over a possible LLCC within the elongated trough and
the upper-level environment remained basically favorable for further
development.
JTWC issued an interim STWO at 0100 UTC on 28 December upgrading the
development potential to fair. Convection had become better organized
and a recent microwave image had revealed enhanced curvature of low-level
cloud lines associated with the deep convection. The disturbance was
estimated to be about 200 nm west-southwest of Diego Garcia, but at
1800 UTC was relocated about 150 nm to the west. A TCFA was issued
at 0000 UTC on 29 December, placing the LLCC about 485 nm west-southwest
of Diego Garcia. Animated enhanced infrared imagery indicated that the
deep convection was becoming better organized around the LLCC. JTWC
issued the first warning on TC-06S at 29/0600 UTC, and at the same time
MFR initiated bulletins on Tropical Disturbance 04 with both agencies
estimating the MSW at 25 kts. The system was then located approximately
500 nm west-southwest of Diego Garcia, moving west-southwestward at
8 kts. An upper-level analysis indicated that the disturbance was
operating in an environment of moderate poleward outflow and moderate
vertical shear.
B. Storm History
----------------
The intensification trend continued and JTWC raised the MSW (1-min
avg) to 35 kts at 29/1800 UTC, based on CI estimates of 30, 35 and
45 kts. However, MFR, following the most conservative estimate, main-
tained the intensity 25 kts through 30/0000 UTC. TC-06S at the time
was tracking southwestward at 8 kts along the northwestern quadrant of
a low to mid-level steering ridge located to the southeast. Outflow
gradually improved on the 30th and the system responded by slowly
strengthening. MFR upgraded the disturbance to tropical depression
status (30 kts) at 0600 UTC, and at 1800 UTC Tropical Storm Darius was
christened by the Mauritius Meteorological Service. At the time, Darius
was centered approximately 375 nm north-northeast of Mauritius, tracking
southwestward at 10 kts. Intensity estimates from MFR and JTWC were
40 and 45 kts, respectively. The storm's track became increasingly
south-southwestward on 31 December and Darius became more and more of
a threat to Mauritius. Microwave imagery around 1800 UTC revealed the
formation of a banding eye feature. This prompted JTWC to upgrade the
MSW (1-min avg) to 65 kts, but MFR never classified Darius as a tropical
cyclone (hurricane). Darius' peak intensity based on MFR's warnings
was 55 kts (10-min avg) for a 24-hour period beginning at 0600 UTC on
1 January.
New Year's Day, 2004, saw Darius reach its peak intensity and then
begin a slow weakening trend. The severe tropical storm's track also
became southerly, lessening the threat somewhat to Mauritius. By 01/1800
UTC Darius was located approximately 140 nm north-northeast of the
island, moving southward at 7 kts. Satellite CI estimates were 55 and
65 kts, and based on a weakening trend apparent in microwave imagery,
JTWC reduced the MSW (1-min avg) to 60 kts. The 2nd of January saw
Tropical Storm Darius slide southward by Mauritius, passing the island
less than 30 nm to the east--at 1800 UTC the center was located only
about 40 nm east-southeast of Mauritius. The storm's intensity as
reported by MFR was 50 kts (10-min avg); CI estimates were ranging from
45 to 65 kts at the time.
By 1800 UTC on 3 January Darius was tracking south-southeastward at
15 kts from a position about 265 nm south-southeast of Mauritius. Winds
were down to 45 kts. Continued slow weakening and transition to an
extratropical LOW were forecast as the storm made its way into higher
latitudes. Acceleration to the southeast continued on the 4th as
animated water vapor imagery depicted weakening deep convection. Both
MFR and JTWC declared Darius extratropical at 04/1200 UTC and issued
their respective final bulletins. The extratropical gale with 40-kt
winds was then located about 600 nm southeast of Reunion Island and
racing southeastward at 26 kts.
C. Meteorological Observations
------------------------------
Patrick Hoareau has sent me a few observations gleaned from various
sources. The center of Darius passed about 43 nm west-northwest of
St. Brandon (16.5S, 59.6E) around 0600 UTC on 1 January. The weather
station there recorded a peak gust of 66 kts, and 135 mm of rain was
recorded during a 24-hour period. The closest approach of the center
to Mauritius was about 21 nm at 1800 UTC on the 2nd of January. Radar
and microwave data showed very clearly that the southeastern quadrant
with the strongest convective bands and strongest winds remained well
out at sea. The western edge of the radar eye impinged on the east and
southeast coasts of Mauritius near 1700 UTC where some locations reported
a lull. Plaisance (the airport and near sea level) on the southeast
coast reported a peak gust of 58 kts, and Souillac on the south coast
recorded a peak gust of 59 kts. Rainfall amounts were near 100 mm in
exposed areas, and these rains were very welcome since the island had
experienced a prolonged drought. All in all, Tropical Storm Darius
was a positive event for Mauritius, bringing much needed rain with the
the most destructive winds remaining over the ocean. (A special thanks
to Patrick for sending me the information.)
D. Damage and Casualties
------------------------
The author has not received any reports of damage or casualties in
Mauritius resulting from Tropical Storm Darius. Given the magnitude of
the peak gusts, it is likely that only minor, scattered wind damage
would have been experienced.
(Report written by Gary Padgett)
*************************************************************************
NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E
Activity for December: 2 severe tropical cyclones (hurricanes)
Sources of Information
----------------------
The primary sources of tracking and intensity information for
Northwest Australia/Southeast Indian Ocean tropical cyclones are
the warnings and advices issued by the Tropical Cyclone Warning
Centres at Perth, Western Australia, and Darwin, Northern Territory.
References to sustained winds imply a 10-minute averaging period
unless otherwise stated.
In the companion tropical cyclone tracks file, I occasionally
annotate positions from warnings issued by the Joint Typhoon Warning
Center (JTWC) of the U. S. Air Force and Navy, located at Pearl
Harbor, Hawaii, when they differ from the Australian centres' coor-
dinates by usually 40-50 nm or more. The JTWC warnings are also the
source of the 1-minute average maximum sustained wind values included
in the tracks file. Additionally, information describing details of
satellite imagery and atmospheric circulation features included in
the narratives is often gleaned from the JTWC warnings.
Northwest Australia/Southeast Indian Ocean
Tropical Activity for December
------------------------------------------
Two tropical cyclones formed in the Southern Hemisphere between
longitudes 135E and 90E during the month of December with both reaching
hurricane (severe tropical cyclone by Australian nomenclature) strength.
Severe Tropical Cyclone Jana formed early in the month northwest of the
Cocos Islands and executed a reverse curvature track around the islands,
moving eastward, then southward, and finally westward as it weakened.
Around mid-month a tropical LOW formed in the northern Gulf of
Carpentaria and moved westward as it slowly intensified. The LOW was
named Tropical Cyclone Debbie on the 18th shortly before it crossed
the 135th meridian. Debbie subsequently took a south-southwestward
track and reached severe tropical cyclone status before moving inland
along the northern coastline of Australia's Northern Territory. Reports
on both Jana and Debbie follow. The report on Debbie was written by
Simon Clarke--a special thanks to Simon for his assistance.
SEVERE TROPICAL CYCLONE JANA
(TC-04S)
7 - 12 December
------------------------------------------------
A. Storm Origins
----------------
An area of convection developed on 3 December about 350 nm northwest
of the Cocos Islands. Animated enhanced infrared imagery indicated
cycling and disorganized deep convection over a possible LLCC, and some
mid-level turning was also noted. An upper-level analysis indicated
moderate diffluence aloft with moderate vertical shear. By the next
day the disturbance was centered about 430 nm northwest of the Cocos
Islands. Deep convection had decreased, and the LLCC appeared to have
opened up somewhat, leaving broad troughing at the surface. The Perth
TCWC mentioned the LOW in their Tropical Weather Outlook, giving the
system a moderate chance of developing into a tropical cyclone within
the next 48-72 hours. On the 5th the system was still further west,
and animated enhanced infrared imagery indicated that the LLCC being
followed was one of several vortices embedded in the monsoon trough.
An upper-level analysis indicated weak diffluence aloft associated
with mostly linear flow. Vertical shear was still moderate.
A STWO issued by JTWC at 1800 UTC on 6 December relocated the system
well back to the east to a position approximately 340 nm northwest of
the Cocos Islands. (Likely, another of the multiple LLCCs mentioned
above had become the dominant center.) The LLCC had consolidated and
was becoming better organized. Also, an upper-level analysis indicated
improving environmental conditions under the subtropical ridge axis
with weaker shear than previously. Perth gave the LOW a high chance
of developing into a tropical cyclone within the next 48-72 hours.
JTWC issued a TCFA at 06/2300 UTC as convection was rapidly increasing
over the well-defined LLCC. The first JTWC warning on TC-04S was
issued at 07/0000 UTC, placing the center approximately 300 nm north-
northwest of the Cocos Islands. The MSW (1-min avg) was estimated at
35 kts, and the system was tracking eastward at 10 kts. Satellite CI
estimates were only 25 kts, but an unflagged QuikScat report of 30 and
40 kts was used as the basis for the warning intensity. The Perth TCWC
issued the first gale warning on the LOW at 07/0400 UTC in anticipation
of the system becoming a tropical cyclone within the next 12 hours.
B. Storm History
----------------
Perth upgraded the LOW to Tropical Cyclone Jana with 40-kt winds at
07/1000 UTC. Jana was then centered approximately 285 nm north-northwest
of the Cocos Islands. (At 1200 UTC JTWC upped the 1-min avg MSW to
50 kts.) By 0000 UTC on 8 December satellite imagery revealed that Jana
had continued to intensify with tightly-curved banding features and both
equatorward and poleward outflow. Perth increased the intensity to
55 kts while JTWC upgraded Jana's winds to 65 kts (1-min avg). The
cyclone at 08/0000 UTC was located about 250 nm north of the Cocos
Islands and moving south-southeastward at 3 kts. The increasing threat
to the islands prompted Perth to issue Tropical Cyclone Advices until the
threat had lessened. At 1000 UTC Perth upped Jana's winds to 70 kts,
making Jana officially a severe tropical cyclone (i.e., hurricane). The
storm was being steered by a mid-level ridge situated to the southeast.
Severe Tropical Cyclone Jana reached its peak intensity on the 9th of
December. Perth's peak intensity (10-min avg) was 75 kts, and JTWC's
peak MSW (1-min avg) was 80 kts. JTWC, however, upped Jana's intensity
to 80 kts after Perth had decreased their MSW estimate to 70 kts. By
1200 UTC Jana was located 140 nm east of the Cocos Islands, moving south
at 9 kts. Hence, the threat posed by the cyclone to the island group
had significantly lessened. Animated water vapor imagery around 0000
UTC on 10 December revealed the first indications of increasing vertical
shear and also a decrease in the poleward outflow channel. The cyclone
was forecast to continue southward for the next 12 hours and then begin
to turn to the southwest as a ridge to the south became the primary
steering mechanism. This forecast verified--at 1200 UTC Jana was
centered about 180 nm south-southeast of the Cocos Islands and moving
southwestward at 8 kts. A 10/0530 UTC TRMM pass had revealed that the
LLCC was north of the deep convection due to northerly wind shear.
Perth had lowered the MSW to 60 kts at 0400 UTC, but JTWC maintained
Jana at 75 kts (1-min avg) based on CI estimates of 65 and 77 kts.
By 0000 UTC on the 11th Jana was moving westward well to the south of
the Cocos Islands. The MSW estimates from Perth and JTWC were 50 kts
and 55 kts, respectively. The system's center had become fully-exposed
with the convection sheared about 80 nm to the southeast of the LLCC.
Jana was forecast to continue weakening in an unfavorable environment of
northerly shear, linear to confluent flow aloft, and marginal SSTs.
This forecast verified--by 1200 UTC convection had significantly
decreased from 12 hours earlier. Jana by this time had weakened to
minimal tropical cyclone intensity, and Perth issued their final gale
warning at 11/2200 UTC. JTWC issued their final warning at 12/0000 UTC,
downgrading the MSW to 30 kts. The convection-free LLCC was located
approximately 225 nm southwest of the Cocos Islands, tracking westward
at 7 kts.
C. Damage and Casualties
------------------------
No damage or casualties are known to have resulted from Severe
Tropical Cyclone Jana.
(Report written by Gary Padgett)
SEVERE TROPICAL CYCLONE DEBBIE
(TC-05P)
17 - 21 December
--------------------------------------------------
A. Storm Origins
----------------
Debbie was the first tropical cyclone of the 2003/2004 season to be
named by the Northern Territory Tropical Cyclone Warning Centre and
the first to make landfall on the Australian mainland for the season.
The cyclone originated from the first significant burst of widespread
thunderstorm activity associated with the developing monsoon trough
to the north of the Australian continent. The Bureau of Meteorology at
Darwin first detected a 1005 hPa tropical LOW on 16 December near
10S, 140W, travelling west at 8 kts. At the time, the tropical LOW
was being subjected to moderate upper-level wind shear. However,
organization continued to improve, and by 17 December banding was
evident along with a small central feature persisting against diurnal
trends. The first gale warning was issued at 17/0700 UTC for a 30-nm
area close to the developing tropical LOW.
The tropical LOW continued to improve in structure while steadily
intensifying. At approximately 18/2100 UTC (or during the early
morning hours of 19 December 2004, Northern Territory time), the
992 hPa tropical low was upgraded to tropical cyclone status and named
Debbie.
B. Storm History
----------------
At the time of naming, slow-moving Tropical Cyclone Debbie was
located about 125 nm north of Elcho Island and 230 nm east-northeast
of Cape Don. Under favourable conditions, including high sea surface
temperatures (28-30 C), Debbie steadily intensified, commencing a
westerly, then southwesterly and finally south-southwesterly track
across the Arafura Sea.
By 19/1500 UTC, Tropical Cyclone Debbie had attained "severe"
Category 3 status as it moved closer to the coast at 5 kts. Debbie
crossed the coast at approximately 20/1130 UTC just east of Goulburn
Island (11.6S, 133.6E). At this time, Severe Tropical Cyclone Debbie
had a central pressure of 970 hPa with a MSW (10-min avg) of 65 kts
(gusts up to 90 kts) and was moving on a south to south-southwesterly
track at 4 kts.
Upon crossing the coast, the cyclone slowly but steadily weakened and
was downgraded to a rain depression at 21/0000 UTC about 100 km east-
southeast of Jabiru. The remnant depression persisted for several days
while trekking southwestward across the Northern Territory, passing
close to Katherine on 22 December, Timber Creek on 23 December, and
finally moving into the Kimberley region of Western Australia on
the 24th.
C. Damage and Casualties
------------------------
The Bureau of Meteorology provided the following comments on Debbie's
impacts:
"No observations were available from near the centre of Tropical
Cyclone Debbie. However, an aerial inspection of the coast affected
by the core of the cyclone between Goulburn Island and Maningrida
revealed severe damage to vegetation with 30-40% of trees felled.
Fortunately, there are no communities along this part of the coast,
apart from a few outstations further inland. No injuries were
reported.
"About 7 hours of gales and 1 hour of near storm-force winds were
recorded at Warruwi Automatic Weather Station, with a maximum wind
gust of 66 kts at 18:30 CST on the 20th (20/0900 UTC). The lowest
pressure recorded at the same station was 989.9 hPa at 16:13 CST.
Structural damage was limited to a few lifted sheets of roofing iron.
Trees fell onto power lines, interrupting power and water supplies
during the cyclone.
"At Maningrida, a brief period of gales with a maximum gust of 44 kts
occurred around 21:30 CST on the 20th (20/1200 UTC). A 2-metre swell
combined with a storm surge caused minor coastal flooding, and the sea
level rose about 0.5 metres above the barge landing. At McCluer Island,
west of Goulburn Island and further away from the landfall area,
sustained gales were recorded for 8 hours, with a maximum wind gust of
51 kts at around 16:00 CST on the 20th (20/0630 UTC)."
As a rain depression, heavy rainfall affected the Arnhem, Darwin-Daly,
Katherine and northern Victoria River Districts, resulting in flooding
in many catchments throughout the Top End. Many areas north of Katherine
reported up to 300 mm of rain during the passage of the cyclone and
associated rain depression. The remnant depression then moved westward
into the Kimberley region of Western Australia. Falls of more than 50 mm
were reported at most Kimberley sites with several locations such as
Ord River Dam (230 mm) and Warmun (172 mm) reporting much higher falls
in the week to 30 December 2003.
One related, but indirect death was reported in the media that could
be attributed to Tropical Cyclone Debbie--a crocodile reportedly mauled
a man to death in a remote part of the Northern Territory. The
authorities in the Northern Territory stated that the heavy rains caused
by Debbie allowed the fierce predators to move farther inland.
(Report written by Simon Clarke)
*************************************************************************
NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E
Activity for December: 1 hybrid or monsoon LOW of gale intensity
Sources of Information
----------------------
The primary sources of tracking and intensity information for
Northeast Australia/Coral Sea tropical cyclones are the warnings
and advices issued by the Tropical Cyclone Warning Centres at
Brisbane, Queensland, and Darwin, Northern Territory, and on very
infrequent occasions, by the centre at Port Moresby, Papua New
Guinea. References to sustained winds imply a 10-minute averaging
period unless otherwise stated.
In the companion tropical cyclone tracks file, I occasionally
annotate positions from warnings issued by the Joint Typhoon Warning
Center (JTWC) of the U. S. Air Force and Navy, located at Pearl
Harbor, Hawaii, when they differ from the Australian centres' coor-
dinates by usually 40-50 nm or more. The JTWC warnings are also the
source of the 1-minute average maximum sustained wind values included
in the tracks file. Additionally, information describing details of
satellite imagery and atmospheric circulation features included in
the narratives is often gleaned from the JTWC warnings.
Northeast Australia/Coral Sea
Tropical Cyclone Activity for December
--------------------------------------
No tropical cyclones were named in the Gulf of Carpentaria or Coral
Sea during December. At the end of the month, an interesting system
formed northwest of New Caledonia, actually spending most of its life
east of 160E, but since Brisbane issued gale warnings on the LOW, I am
covering it here. The Tropical Cyclone Outlook issued by Brisbane on
30 December stated that "a strong upper LOW near New Caledonia is
producing a low-pressure system to its northeast. Global computer models
indicate the formation of a monsoon LOW in the eastern Coral Sea in the
next 24 to 48 hours owing to the upper LOW. Models develop this complex
system and move it westwards towards the Queensland coast late in the
week. At this stage this system it not expected to form into a classical
tropical cyclone--it is expected to be a vigorous LOW with gales removed
from the system centre."
That pretty much sums up what transpired over the next few days. At
1800 UTC on the 30th a LOW was centered roughly 265 nm north-northwest
of Noumea, producing 30-kt winds. The system moved slowly in a westerly
direction for the next couple of days, producing winds up to 35 kts.
The LOW began to weaken late on 1 January 2004 with Brisbane issuing the
final gale warning at 01/2200 UTC, the center being located approximately
400 nm northwest of Noumea. The Nadi TCWC also issued general gale
warnings for the areas affected by the system.
(NOTE: I did produce a track for this system in the December tropical
cyclone tracks file. There was a missing data point indicated for
0600 UTC on 1 January, which I discovered later was due to my having
filed the appropriate warning in the wrong folder. The particulars
for 01/0600 UTC are: Lat. 18.5S, Lon. 160.5E, CP 996 hPa, and a MSW
of 35 kts (10-min avg), all based on the Brisbane warning. I have
dispatched a corrected tracks file to the gentlemen who archive the
summaries and tracks.)
*************************************************************************
SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E
Activity for December: 2 tropical depressions
Sources of Information
----------------------
The primary sources of tracking and intensity information for
South Pacific tropical cyclones are the warnings and advisories
issued by the Tropical Cyclone Warning Centres at Nadi, Fiji (for
waters north of latitude 25S), and Wellington, New Zealand (for
waters south of latitude 25S). References to sustained winds imply
a 10-minute averaging period unless otherwise stated.
In the companion tropical cyclone tracks file, I occasionally
annotate positions from warnings issued by the Joint Typhoon Warning
Center (JTWC) of the U. S. Air Force and Navy, located at Pearl
Harbor, Hawaii, when they differ from the Southern Hemisphere
centres' coordinates by usually 40-50 nm or more. The JTWC warnings
are also the source of the 1-minute average maximum sustained wind
values included in the tracks file. Additionally, information
describing details of satellite imagery and atmospheric circulation
features included in the narratives is often gleaned from the JTWC
warnings.
South Pacific Tropical Activity for December
--------------------------------------------
No tropical cyclones formed during the month of December in the South
Pacific basin east of 160E. A tropical disturbance well to the north-
west of Fiji was designated as Tropical Disturbance 01F early in the
month, and was referred to as a "weak tropical depression" on the 5th
and 6th. The system had weakened by late on the 6th due to strong
vertical shear. No track was given for this weak system in the December
cyclone tracks file. Tropical Disturbance 03F was first noted on
Christmas Day well to the north of Fiji. This system drifted very slowly
eastward during the following days and was referred to as a tropical
depression on the 28th when it was very near the International Dateline.
The depression continued to develop very slowly as it continued drifting
eastward, and on 2 January was upgraded to Tropical Cyclone Heta. Heta
became a very intense cyclone and devastated the small island nation of
Niue. Heta will be covered in the January summary.
*************************************************************************
EXTRA FEATURE
In order to shorten the amount of typing in preparing the narrative
material, I have been in the habit of freely using abbreviations and
acronyms. I have tried to define most of these with the first usage
in a given summary, but I may have missed one now and then. Most of
these are probably understood by a majority of readers but perhaps a
few aren't clear to some. To remedy this I developed a Glossary of
Abbreviations and Acronyms which I first included in the July, 1998
summary. I don't normally include the Glossary in most months in
order to help keep them from being too long. If anyone would like to
receive a copy of the Glossary, please e-mail me and I'll be happy
to send them a copy.
*************************************************************************
AUTHOR'S NOTE: This summary should be considered a very preliminary
overview of the tropical cyclones that occur in each month. The cyclone
tracks (provided separately) will generally be based upon operational
warnings issued by the various tropical cyclone warning centers. The
information contained therein may differ somewhat from the tracking and
intensity information obtained from a "best-track" file which is based
on a detailed post-seasonal analysis of all available data. Information
on where to find official "best-track" files from the various warning
centers will be passed along from time to time.
The track files are not being sent via e-mail. They can be retrieved
from the archive sites listed below. (Note: I do have a limited e-mail
distribution list for the track files. If anyone wishes to receive
these via e-mail, please send me a message.)
Both the summaries and the track files are standard text files
created in DOS editor. Download to disk and use a viewer such as
Notepad or DOS editor to view the files.
The first summary in this series covered the month of October,
1997. Back issues can be obtained from the following websites
(courtesy of Michael Bath, Michael V. Padua, Michael Pitt, and
Chris Landsea):
http://australiasevereweather.com/cyclones/>
http://www.typhoon2000.ph>
http://mpittweather.com>
ftp:// ftp.aoml.noaa.gov/hrd/pub/landsea/padgett/>
Another website where much information about tropical cyclones may
be found is the website for the UK Meteorological Office. Their site
contains a lot of statistical information about tropical cyclones
globally on a monthly basis. The URL is:
http://www.met-office.gov.uk/sec2/sec2cyclone/sec2cyclone.html>
TROPICAL CYCLONE REPORTS AVAILABLE
JTWC now has available on its website the complete Annual Tropical
Cyclone Report (ATCR) for 2002 (2001-2002 season for the Southern
Hemisphere). ATCRs for earlier years are available also. The report
for the 2002-2003 Southern Hemisphere season has also recently been
added.
The URL is: http://199.10.200.33/jtwc.html>
Also, TPC/NHC has available on its webpage nice "technicolor"
tracking charts for the 2003 Atlantic and Eastern North Pacific
tropical cyclones; also, storm reports for all the 2003 Atlantic
and Eastern North Pacific cyclones are now available, as well as
track charts and reports on storms from earlier years.
The URL is: http://www.nhc.noaa.gov>
A special thanks to Michael Bath of McLeans Ridges, New South Wales,
Australia, for assisting me with proofreading the summaries.
PREPARED BY
Gary Padgett
E-mail: [email protected]
Phone: 334-222-5327
Kevin Boyle (Eastern Atlantic, Western Northwest Pacific, South
China Sea)
E-mail: [email protected]
Simon Clarke (Northeast Australia/Coral Sea, South Pacific)
E-mail: [email protected]
*************************************************************************
*************************************************************************
|
Document: summ0312.htm
Updated: 26th October 2006 |
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