GARY PADGETT'S
MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY
NOVEMBER, 2005
(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.)
*************************************************************************
NOVEMBER HIGHLIGHTS
--> Three more Atlantic tropical storms up 2005 total to 26 named storms
--> Western North Pacific and North Indian Ocean see some activity
--> Intense tropical cyclone roams South Indian Ocean waters
*************************************************************************
ACTIVITY BY BASINS
ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico
Activity for November: 3 tropical storms **
** - one of these reached hurricane intensity in early December
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 November
---------------------------------------
Following the dissipation of Hurricane Beta over the mountains of
Nicaragua during the final days of October, the Atlantic basin enjoyed
a two-week respite from the almost non-stop tropical cyclone activity
it had seen since July. However, things started bubbling again in the
Caribbean and subtropics during the middle and latter parts of the month.
After traversing the length of the Caribbean Sea as a tropical
depression, Tropical Storm Gamma formed just off the coast of Honduras
around mid-month and lingered in the same area for a few days until it
dissipated. The east-central Atlantic subtropics then became a hotspot,
producing two tropical cyclones within a few days of each other during
the final days of November, plus another to come in late December.
Tropical Storm Delta formed on the 23rd and followed an unusual southerly
track before taking off to the east-northeast on the 26th. Delta became
a strong tropical storm, and there is a possibility that it briefly
reached hurricane intensity on 27 November, but the data were deemed not
conclusive enough to justify a posthumous upgrade to hurricane status.
Shortly after becoming an extratropical LOW, Delta swept by the Canary
Islands on its way to a Moroccan landfall, causing extremely strong
winds in the islands which led to widespread damage. Finally, another
non-tropical LOW on the heels of Delta acquired tropical characteristics
on 29 November and was named Tropical Storm Epsilon. Epsilon became a
hurricane on 2 December and remained so for 5 days--the longest-lived
December hurricane on record.
Most of the official TPC/NHC reports for 2005 Atlantic tropical
cyclones are now available online at the following link:
Since the reports for all three November storms are now available, I have
written only fairly brief reports on these systems, based largely on the
official storm reports.
Climatologically speaking, November, 2005, was one of the more active
months of November on record in terms of named storms, equaling the
record of three established in 2001. (Technically, Hurricane Michelle
was upgraded to a tropical storm shortly before 0000 UTC on 1 November,
but anyone using the Best Track file would see the first 35-kt MSW
at 01/0000 UTC and so would count it as a November tropical storm.)
However, all three of the 2001 storms became hurricanes, while none of
the 2005 cyclones did, except for Epsilon in December, so it counts as
a December hurricane. Based on the period 1950-2004, the NTC generated
by Gamma, Delta, and the first 1.5 days of Epsilon amounts to 7.7%,
above the November average NTC of 4.0% but far less than the 34.8% in
November, 2001, or the 22.9% in November, 1999. Other fairly active
Novembers include:
Year NS H IH NTC
----------------------------------------
1956 1 1 1 18.5%
1969 2 2 0 13.3%
1980 2 2 0 13.9%
1985 1 1 1 21.2%
1994 2 2 0 17.2%
1999 1 1 1 22.9%
2001 3 3 1 34.8%
TROPICAL STORM GAMMA
(TC-27)
14 - 21 November
----------------------------------------
The official TPC/NHC storm report on Tropical Storm Gamma, written
by Stacy Stewart, is now available on NHC's website.
Tropical Storm Gamma, the 24th named tropical storm of the 2005
Atlantic season, formed from an unusually late-season vigorous tropical
wave which moved off the coast of western Africa on 3 November. The
wave was accompanied by an unusually large amount of deep convection and
produced wind gusts to near tropical storm force with locally heavy
rainfall as it moved across the southern Windward Islands on 13 November.
Unfavorable vertical shear relaxed some once the system had entered
the southeastern Caribbean Sea, and it had become organized enough such
that advisories were initiated on Tropical Depression 27 at 0300 UTC on
the 14th. The depression was centered about 100 nm west of St. Lucia
or about 90 nm west of St. Vincent, moving west-northwestward at 9 kts.
The depression was forecast to strengthen into a tropical storm, and
according to the official report, it did reach minimal tropical storm
intensity for about 12 hours at 0600 UTC on 15 November while located
well to the south of Puerto Rico. However, westerly shear increased
and the system had weakened to a depression by 15/1800 UTC. The NHC
storm report seems to imply that the depression was named Tropical Storm
Gamma at this time, but the system was not treated as a tropical storm
at this stage operationally. The depression continued to weaken and
was downgraded to a tropical wave and advisories terminated at 1500 UTC
on 16 November with the center of the remnants of TD-27 located about
265 nm southeast of Kingston, Jamaica. A deep-layer ridge to the north
forced the remnants of TD-27 to accelerate westward at 20-22 kts across
the central Caribbean Sea before slowing down near eastern Honduras on
17 November.
During the same time interval a broad but well-defined low-pressure
system had formed over Panama and moved northwestward over the south-
western Caribbean and into northeastern Nicaragua on 16 November. This
system either merged with or underwent a complex interaction with the
remnants of TD-27 over the mountainous terrain of Honduras early on the
18th. A midday reconnaissance flight found that a broad circulation
had formed just north of the Honduran coast with a peak FLW of 49 kts at
450 metres along with two spots of 45 kts north of the center. Based
on these observations, advisories were re-initiated on the system as
Tropical Storm Gamma at 18/2100 UTC, placing the center about 35 nm north
of Limon, Honduras. Steering currents were very weak and over the next
three days Tropical Storm Gamma moved very slowly and erratically along
and just to the north of the eastern Honduran coastline. The peak MSW
assigned operationally to Gamma was 40 kts, but the Best Track file shows
that in post-storm analysis the intensity was upped slightly to 45 kts
at 19/1200 UTC when it was located just east of Roatan Island.
Later on the 19th Gamma began a slow drift to the east, and the next
day began moving more quickly to the southeast. Shear began to increase
from the northwest and displaced most of the convection well to the
southeast of the LLCC. Gamma began to weaken and was downgraded to a
tropical depression at 20/1200 UTC. By early on 21 November Gamma had
degenerated into a non-convective remnant LOW and had dissipated by
0600 UTC on 22 November just east of the Honduras-Nicaragua border.
A graphic depicting the operational track of Tropical Storm Gamma may
be found at the following link:
Reports from the Government of Honduras and the news media indicate
that 37 fatalities occurred due to Tropical Storm Gamma: 34 in Honduras
and 3 in Belize. The deaths were the result of flash floods and mud-
slides caused by the heavy rainfall. An additional 13 persons were
listed as missing in Honduras. More than 100,000 residents of Honduras
were adversely affected by Gamma as their homes were damaged and the
electrical service interrupted. There was also a shortage of food and
water. The floods destroyed 5200 acres of banana crops, and reports from
private companies indicate that banana crop losses were around $13-$18
million U. S. dollars.
(Report written by Gary Padgett, based on the official TPC/NHC storm
report by Stacy Stewart)
TROPICAL STORM DELTA
(TC-28)
21 - 30 November
----------------------------------------
The official TPC/NHC storm report on Tropical Storm Delta, written by
Jack Beven, is now available on NHC's website.
Delta, the 25th named storm of the 2005 Atlantic hurricane season, was
the first in a series of three late-season storms of non-tropical origin
to form in the east-central subtropical Atlantic. Delta was unique in
the annals of Atlantic tropical history in that it caused, in its extra-
tropical stage, extremely strong winds well above hurricane force in the
Canary Islands which led to widespread damage. Also, the post-Delta
extratropical cyclone is the only case known to the author in which a
former tropical cyclone struck the African continent with gale-force
winds or higher.
Delta's origins lay with a broad low-pressure area which formed on
19 November about 1200 nm southwest of the Azores. Initial motion was
east-northeastward through the 20th while it was located in the vicinity
of a cold front trailing from another LOW to the north. The pre-Delta
system then turned northeastward on 21 November and began developing
some central convection. On the morning of the 22nd QuikScat data
indicated the formation of an inner wind maximum while AMSU data
revealed that an upper-level warm core had formed--both characteristics
of subtropical and tropical cyclones. The LOW subsequently became more
isolated from frontal cloud bands and began a south-southwestward
motion late that day. The convection consolidated and advisories were
initiated on Tropical Storm Delta at 2100 UTC on 23 November. The center
was estimated to be located about 1000 nm southwest of the Azores with
a MSW of 50 kts. QuikScat data showed a few uncontaminated 50-kt wind
vectors, and Buoy 62556, located about 50 nm east of the center, reported
a pressure of 986.5 mb at 23/1600 UTC.
(Note: In post-storm analysis it was determined that the system had
become classifiable as a subtropical storm by 22/1800 UTC, and the Best
Track reflects this. However, it was not classified as a subtropical
storm operationally.)
Over the next couple of days Tropical Storm Delta moved generally
southward, initially southeastward followed by a turn to the southwest.
Delta's intensity increased slowly, reaching a first peak of 60 kts by
1200 UTC on 24 November. The southerly motion slowed and Delta turned
eastward and then east-northeastward on the 26th. During this period
vertical shear increased and the cyclone had weakened into a minimal
35-kt tropical storm by 1200 UTC on the 26th. Delta began to
accelerate to the east-northeast on the 27th in response to an
intensifying deep-layer trough over western Europe. The storm surprised
forecasters as it underwent a sharp re-intensification on the 27th. In
fact, during the evening of 26 November some very deep convection with
tops colder than -70 C developed to the east-northeast of the mostly-
exposed LLCC. This persisted throughout the night, and the discussion
bulletin at 27/0900 UTC noted that the convection was about as strong
as it had been during the lifetime of the cyclone. But given the
uncertainty in just where the center was located in relation to the
deep convection, the MSW remained at 35 kts as Delta was expected to
soon weaken and become extratropical.
During the morning Delta developed an eye-like feature in visible and
infrared imagery, so the MSW was bumped up to 45 kts at 1500 UTC. Low-
level cloud lines suggested that the surface center was located a little
to the southwest of the mid-level eye. The MSW was increased to a
second peak of 60 kts at 2100 UTC based on a report of 60-kt winds and
a pressure of 991 mb at 1800 UTC from ship VQIB9, which was located about
50 nm north of the center and had a history of reliable observations.
The satellite appearance, however, had already begun to deteriorate by
this time so no additional strengthening was considered likely. On the
28th Delta turned more to the east as it moved into a surface baroclinic
zone associated with the European trough. The storm began to lose its
tropical characteristics due to increasing vertical shear and cold air
entrainment and was declared extratropical at 28/1500 UTC. The final
TPC/NHC advisory placed Delta's center about 150 nm northwest of La Palma
in the Canary Islands, racing eastward at 26 kts. The remnants of Delta
continued eastward, passing about 90 nm north of the Canaries later that
day with winds still estimated at 60 kts. The storm moved into Morocco
early on 29 November and accelerated rapidly east-northeastward while
weakening. It had dissipated over northwestern Algeria by late on the
29th.
The possibility exists that Delta did reach hurricane intensity for
a brief period on 27 November, based on the satellite signature in
visible, infrared and microwave imagery and the 60-kt ship report in
what would normally be the weaker side of a cyclone moving rapidly
eastward. However, the data were not considered compelling enough to
justify an after-the-fact upgrade to hurricane status.
A graphic depicting the operational track of Tropical Storm Delta
may be found at the following link:
Some very strong winds were reported in the Canary Islands from the
extratropical remnants of Delta. A station on Tenerife reported
sustained winds of 63 kts, gusting to 79 kts while a station on La Palma
measured a peak gust of 82 kts. The Izana Observatory, located at an
altitude of 2367 metres reported sustained winds of 98 kts with a peak
gust of 134 kts.
No deaths or damages were associated with Delta during its time spent
as a tropical cyclone, but as an extratropical LOW it was responsible for
7 deaths in and near the Canary Islands, including 6 African migrants who
drowned when their boat capsized. Also, 12 additional people from the
boat were reported missing. Power outages were common throughout the
Canaries, while roads were blocked by trees and mudslides. Several ports
and airports were temporarily closed by the storm, and the strong winds
broke a huge rock and natural monument near Agaete, known as the "Finger
of God."
(Report written by Gary Padgett, based on the official TPC/NHC storm
report by Jack Beven)
HURRICANE EPSILON
(TC-29)
28 November - 9 December
--------------------------------------------
The official TPC/NHC storm report on Hurricane Epsilon, written by
James Franklin, is now available on NHC's website.
Epsilon was the 26th named tropical cyclone of the 2005 Atlantic
hurricane season and became the 15th hurricane of the year. The cyclone
formed from a non-tropical area of low pressure in the central Atlantic
on 29 November about 735 nm east of Bermuda. Coming on the heels of
Tropical Storm Delta, Epsilon was the second tropical cyclone to form
in the same area within a week. The parent surface gale center had
formed on 27 November beneath a non-tropical upper-level LOW, and the
transition to a tropical cyclone apparently occurred rather quickly.
The official report notes that on 28 November the system did exhibit
some of the features of a classic subtropical cyclone, and that a case
could be made for classifying it as subtropical late on the 28th.
However, since the LOW did not have much organized non-frontal convection
prior to 0600 UTC on 29 November, the decision was made not to classify
the pre-Epsilon system as a subtropical storm.
After being named as a tropical storm, Epsilon moved westward, then
dropped to the south and eventually to the northeast, completing a loop.
On 2 December, while heading northeastward over 1000 nm west of the
Azores, Epsilon was upgraded to hurricane status. This was in spite of
moving over slightly cooler SSTs since the previous day. A solid
convective band surrounded a well-defined 25-nm diameter eye, and the
upper-level outflow pattern had continued to improve. The hurricane,
however, was forecast to weaken back into a tropical storm in less than
24 hours. Almost every 6-hourly forecast over the next several days
expected Epsilon to remain a hurricane for no more than 24 hours--yet
the tenacious storm held on to hurricane intensity for over 5 days.
Epsilon generated 5.5 hurricane days in the month of December, doubling
the previous high of 2.75 hurricane days set by Hurricane Lili in 1984.
(Note: In post-analysis, Epsilon's tenure as a hurricane was reduced
by 6 hours at each end, so that based on the Best Track, Epsilon was
a hurricane for 5 days.)
On 3 December Epsilon's track turned eastward--a track which it was
to follow for the next 3 days. This easterly track kept the storm to
the south of a belt of strong westerlies. Anticyclonic outflow
developed in the northern semicircle and Epsilon took on an annular
appearance with a large 30-35 nm diameter eye. The estimated peak
intensity of 75 kts occurred early on 5 December. Later on the 5th, the
frontal zone associated with a deep-layer trough passed just north of
Epsilon with high pressure building behind the trough. This forced
the hurricane to embark on a southerly and later southwesterly course.
Vertical wind shear remained fairly weak and Epsilon continued to hold
on to minimal hurricane intensity for another 2 days. However, as
Epsilon continued to move to the southwest, strong upper-level north-
westerly flow began to affect the cyclone and it began to weaken.
Operationally, Epsilon was downgraded to a tropical storm at 0300 UTC
on 8 December while located about 865 nm southwest of the Azores.
After this, weakening was rapid and Epsilon was downgraded to a tropical
depression on the final NHC advisory at 08/1500 UTC, still moving
southwestward.
A graphic depicting the operational track of Hurricane Epsilon may
be found at the following link:
(Report written by Gary Padgett, based upon the official TPC/NHC report
by James Franklin)
*************************************************************************
NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180
Activity for November: No tropical cyclones
*************************************************************************
NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180
Activity for November: 1 tropical depression **
1 tropical storm
2 typhoons ++
** - system was classified as a tropical depression by the Central
Weather Bureau of Taiwan only
++ - one of these formed in October and was covered in the October
summary
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 November
------------------------------------------------
November tropical cyclone activity was about normal during 2005.
As the month opened Typhoon Kai-tak was losing steam in the South China
Sea and continued to weaken until its landfall in Vietnam on the 2nd.
The report on Kai-tak was included in the October summary. Two named
storms formed in November--Tropical Storm Tembin and Typhoon Bolaven.
The fairly weak Tembin, known in the Philippines at Ondoy, began forming
well to the east of Palau on the 6th, and generally followed a west-
northwesterly track until it made landfall in central Luzon on the 10th.
The storm weakened while crossing the island and dissipated in the South
China Sea on the 12th.
Typhoon Bolaven (its PAGASA-assigned name being Pepeng) formed east
of Mindanao around mid-month, trekked northward, then slowed and moved
very erratically for a couple of days as it intensified to typhoon
status. Finally, the cyclone took off on a west-northwesterly track
but had weakened into a minimal tropical storm before making landfall
in extreme northeastern Luzon on the 20th. Another tropical LOW was
classified as a weak tropical depression by the Central Weather Bureau
of Taiwan (CWB) but apparently not by any other agency. The primary
significance of this system was that it underwent a binary action with
Bolaven and was likely a contributing factor to the typhoon's very
erratic track on the 15th-17th. Huang Chunliang sent me a tabular track
of this depression, so because of its influence on Typhoon Bolaven, I
have included the CWB track in the report on Bolaven.
TROPICAL STORM TEMBIN
(TC-23W / TS 0522 / ONDOY)
6 - 12 November
----------------------------------------------
Tembin: contributed by Japan, means 'balance' (weighing device); also
is the name of the constellation Libra (the scales)
A. Introduction and Storm Origins
----------------------------------
Tropical Storm Tembin developed in the monsoon trough on 7 November.
Moving rather quickly west-northwestwards, it reached a maximum intensity
of 45 kts before making landfall on the northern Philippine island of
Luzon late on 10 November. It dissipated near Taiwan on 12 November.
At 0600 UTC 4 November an area of convection persisted approximately
330 nm east-southeast of Palau. Animated multi-spectral satellite
imagery showed a consolidating LLCC with deep convection on the
southwestern periphery. An upper-level analysis indicated that the
disturbance was located in an area of low vertical shear, and a good
outflow channel was evident to the east. The system slowly became
better organized over the following two days, and a TCFA was issued at
06/1430 UTC. The first warning followed at 07/0600 UTC, placing the
centre of the newly-formed Tropical Depression 23W approximately 75 nm
north-northwest of Yap.
B. Synoptic History
-------------------
Moving northwestward at 10 kts, Tropical Depression 23W was upgraded
to a tropical storm at 1800 UTC 7 November when located approximately
220 nm north-northwest of Yap. Influenced by a low to mid-level
steering ridge located to the northeast, Tropical Storm 23W turned onto
a west-northwesterly track and became disorganized on 8 November as it
struggled to establish a favourable outflow pattern, virtually losing
its supporting deep convection and exposing the LLCC. As a result, it
was downgraded to a tropical depression at 08/1200 UTC shortly after
entering PAGASA's AOR. That agency assigned the named Ondoy for local
use.
On 9 November the environment became more conducive for
strengthening, and the tropical cyclone was re-upgraded to a 35-kt
tropical storm at 0600 UTC 9 October. Tropical Storm 23W reached its
peak intensity of 45 kts at 09/1200 UTC while located approximately
405 nm east of Manila, Philippines. This was maintained for the
following 24 hours, the system continuing on a rather brisk west-
northwestward heading south of a intensifying low to mid-level ridge.
JMA raised their MSW estimate to 35-kts and assigned the name Tembin at
10/0000 UTC. Tropical Storm Tembin/Ondoy made landfall on Luzon at
10/1200 UTC at a point approximately 75 nm north-northeast of Manila
with the MSW estimated at 45 kts. Once over land, Tembin deteriorated
markedly and was downgraded to a tropical depression at 11/0600 UTC.
The final warning was issued at 11/1800 UTC after the deep convection
had mostly dissipated and the LLCC had become barely discernible. The
final position was approximately 235 nm southeast of Hong Kong, China.
JMA had released their final statement at 11/0600 UTC. The remnants of
Tembin moved northwest and dissipated near Taiwan on 12 November.
NMCC and PAGASA estimated a peak intensity of 45 kts (10-min avg).
JMA, HKO, CWB of Taiwan and TMD estimated a peak value of 35 kts. The
lowest CP estimated by JMA was 1000 mb.
A graphic depicting the track of Tropical Storm Tembin/Ondoy may be
found at the following link:
C. Damage and Casualties
------------------------
There were no reports of damage or casualties in the Philippines
associated with Tropical Storm Tembin/Ondoy.
(Report written by Kevin Boyle)
TYPHOON BOLAVEN
(TC-24W / STS 0523 / PEPENG)
13 - 20 November
------------------------------------------------
Bolaven: contributed by Laos, is the name of a plateau in southern Laos
A. Introduction and Storm Origins
----------------------------------
As Tropical Storm Tembin was dissipating southeast of Taiwan,
Typhoon Bolaven began developing east of the Philippines. This system
consistently had to face unfavourable wind shear, taking several days
to reach typhoon strength and its peak intensity of 75 kts on
17 November. It made landfall over northeastern Luzon, Philippines,
as a weakening tropical storm on 20 November.
On 12 November an area of convection persisted approximately 150 nm
west-southwest of Palau. Remarks in JTWC's TCFA issued at 2200 UTC 12
November include: "A 12/1617 UTC AMSR/E pass and animated enhanced
infrared satellite imagery reveals a well-defined and tightening LLCC
with deep convection increasing in close proximity to it. An upper-
level analysis indicates the area is under low vertical wind shear and
outflow is gradually becoming more favourable for development with good
diffluence to the west and north." The first warning on Tropical
Depression 24W was released at 13/1200 UTC, placing the centre
approximately 290 nm west of Palau. Intensifying, TD-24W was upgraded
to a 35-kt tropical storm at 14/0600 UTC. The system had been named
Pepeng six hours earlier when PAGASA classified it as a tropical
depression.
B. Synoptic History
-------------------
Tropical Storm 24W moved erratically northwards over the next two
days as a weakness developed in the mid-level steering ridge induced by
a passing mid-latitude trough. The tropical cyclone intensified slowly
under moderate to high vertical wind shear, and as a result, the deep
convection became displaced west of the LLCC on 15 November. The
system was named Bolaven at 16/0600 UTC when JMA raised their 10-min
avg MSW to 35 kts. On 16-17 November, Tropical Storm Bolaven drifted
aimlessly to the east of the Philippines as it became lodged between
weak steering current regimes. Despite exhibiting a large and very
symmetric CDO, microwave satellite images at 16/1200 UTC revealed that
the deep convection was still located west of the LLCC. However, after
the shear lessened and radial outflow improved, Bolaven was upgraded to
a 65-kt typhoon at 0000 UTC 17 November, centred approximately 480 nm
east of Manila. (See Section E below.)
Intensifying, Typhoon Bolaven quickly reached its peak intensity of
75 kts at 1200 UTC 17 November while located approximately 430 nm east
of Manila. The peak MSW was maintained for only six hours and Bolaven
began to weaken in the face of less favourable environmental conditions.
Increasingly influenced by a steering ridge over southeast Asia,
the tropical cyclone began to drift towards the west-northwest on
18 November. Bolaven was downgraded to a 60-kt tropical storm at
18/1800 UTC, being located approximately 320 nm east of Manila.
Turning northwestwards, the system continued to weaken and made
landfall over northeastern Luzon early on 20 November with the MSW
estimated at around 40 kts. JTWC issued the final warning at 20/1200
UTC, six hours after downgrading Bolaven to a tropical depression. The
system dissipated later that day.
NMCC and PAGASA estimated a maximum intensity of 65 kts while JMA,
HKO, CWB of Taiwan estimated a peak strength of 60 kts. JMA estimated
a minimum CP of 976 mb.
A graphic depicting the track of Typhoon Bolaven/Pepeng may be
found at the following link:
C. Damages and Casualties
-------------------------
There were no reports of damage or casualties associated with
Typhoon Bolaven/Pepeng.
D. Naga City Observations
-------------------------
E. Additional Discussion
------------------------
Mark Lander posted an e-mail to a discussion list pointing out that
the slow and erratic motion of Bolaven was in part due to a binary
interaction with an unnumbered system to the northeast. That particular
system was treated as a tropical depression by the Central Weather Bureau
of Taiwan (CWB). The CWB track, sent by Huang Chunliang, follows. The
CWB normally does not make wind estimations for tropical depressions.
CWB Track for Tropical Depression (NRL Invest 99W)
Date Press &
& Time Status Wind(m/s) Position
====== ====== ========= ============
111400 TD 1002/-- 14.0N 139.8E
111406 TD 1002/-- 13.4N 138.3E
111412 TD 1002/-- 15.8N 136.1E
111418 TD 1002/-- 16.9N 135.3E
111500 TD 1002/--
17.5N 134.5E
111506 TD 1002/-- 18.0N 134.0E
111512 TD 1002/-- 18.0N 134.0E
111518 TD 1002/-- 18.5N 135.5E
111600 TD 1002/-- 20.5N 136.9E
(Report written by Kevin Boyle, with additional information supplied by
Michael V. Padua and Huang Chunliang)
*************************************************************************
NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea
Activity for November: 1 depression
1 cyclonic storm
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.
North Indian Ocean Tropical Activity for November
-------------------------------------------------
The fairly active fall transitional season in the Bay of Bengal, which
had seen one tropical cyclone in September and two in October, continued
during the latter part of November with two systems tracked. The first
was a tropical depression from 20-22 November which formed just east of
Sri Lanka and moved erratically near the island, eventually crossing
the northern tip. JTWC never issued any warnings on this system but
did assigned a 'fair' potential for development. IMD treated it as a
weaker depression with 25-kt winds, but the Thai Meteorological Depart-
ment assigned a MSW of 30 kts for a couple of warning cycles. A graphic
depicting the track of this system (NRL Invest 94B) may be found at the
following link:
The other Bay of Bengal system was Cyclonic Storm Baaz, which formed
late in the month in the east-central Bay and moved westward, becoming
a 45-kt tropical storm but weakening into a depression before reaching
India's southeastern coastline in early December. A report follows on
Cyclonic Storm Baaz.
CYCLONIC STORM BAAZ
(BOB0503 / TC-05B)
27 November - 3 December
--------------------------------------------
Baaz: contributed by Oman
On 26 November an area of persistent convection had developed in the
Bay of Bengal approximately 300 nm northwest of Penang, Malaysia.
Animated satellite imagery indicated the possibility of a LLCC. An
upper-level analysis showed increasing 850-mb vorticity and moderate
vertical wind shear. The potential for development was assessed as
'poor', but this was upgraded to 'fair' in an interim STWO issued by
JTWC at 27/0100 UTC. The system was then located about 500 nm northwest
of Penang and deep convection was consolidating around a developing LLCC.
Aloft, vertical shear was decreasing and divergence increasing. The
disturbance continued to steadily develop and a TCFA was issued at 1200
UTC followed by the first JTWC warning on Tropical Cyclone 05B at 1800
UTC. The 30-kt center was then estimated to be located approximately
650 nm east of Madras, India, and was tracking westward at 10 kts along
the southwestern periphery of a low to mid-level ridge. Also at 1800
UTC on the 27th, the Thai Meteorological Department (TMD) classified
the system as a tropical depression and began issuing bulletins.
The system continued moving generally westward across the Bay of
Bengal and gradually intensified. By 28/1800 UTC the storm had reached
its peak intensity of 45 kts (per JTWC's analysis) and was located about
425 nm east-southeast of Madras, India. The IMD had upgraded and named
the system Cyclonic Storm Baaz by 28/1800 UTC. (The peak intensity
estimated by IMD was also 45 kts.) Baaz continued moving on a west-
northwestward track and maintained strength until the morning of
1 December, when it began to weaken due to increasing vertical wind
shear. The storm's motion slowed and became somewhat erratic on
30 November as it neared the Indian coastline. JTWC issued their
final warning on Baaz at 0600 UTC on 2 December, placing the completely-
exposed center about 110 nm east-southeast of Madras. The TMD continued
to track the depression until it had moved inland north of Pondicherry
on 3 December. It is possible that Baaz was slightly stronger than
indicated in the warnings from the various agencies. On 29 November
SAB was assigning Dvorak intensity estimates of T3.5, or 55 kts.
During its pre-tropical cyclone phase, the disturbance which became
Cyclonic Storm Baaz (NRL Invest 96B) brought very heavy rain to southern
Thailand. Ko Samui (WMO 48550) reported 417.0 mm during the 24-hour
period ending at 25/0600 UTC. The rains brought destruction to southern
Thailand. A preliminary report stated that 11 people were killed and
hundreds of businesses destroyed. The preliminary damage estimate was
around 400 million Thai baht, which is roughly 9 to 10 million U. S.
dollars. (The rainfall information was from Huang Chunliang; the damage
report from Phil Smith.)
A graphic depicting the track of Cyclonic Storm Baaz may be found at
the following link:
No reports of damage or casualties have been received from India in
the region where the remnant depression made landfall.
(Report written by Gary Padgett)
*************************************************************************
SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E
Activity for November: 2 tropical depressions **
1 intense tropical cyclone ++
** - one of these formed in the Western Australian region and was treated
as a cyclone of gale intensity by JTWC
++ - system formed in the Western Australian region
Southwest Indian Ocean Tropical Activity for November
-----------------------------------------------------
Three tropical systems of depression intensity or stronger roamed
South Indian Ocean waters west of 90E during November, but only one
formed there. This system, numbered as Tropical Depression 03 by
MFR, formed on 6 November a few hundred miles east-southeast of Diego
Garcia and drifted southward for a couple of days before weakening,
reaching an estimated intensity of 30 kts. JTWC issued a TCFA for this
LOW, but never issued any warnings. A graphic depicting the track of
this depression may be found at the following link:
Another system which had actually formed earlier in Australian waters
east of 90E intensified into a tropical storm per JTWC's assessment and
was designated TC-02S by that agency. BoM Perth, however, did not name
the system as a tropical cyclone, and neither did Mauritius when it
crossed 90E into the Southwest Indian Ocean proper. The system was
already beginning to weaken when it crossed 90E, but MFR numbered it as
Tropical Depression 04 and issued bulletins until it dissipated on
8 November. The other tropical system likewise formed in Perth's AOR
and entered the Mauritius/La Reunion region, but this one became the
first intense tropical cyclone of the season in the South Indian Ocean.
Named Bertie by BoM Perth, the cyclone crossed 90E near its peak
intensity of 100 kts and was renamed Alvin by Mauritius. Reports on
TC-02S/MFR-04 and Intense Tropical Cyclone Bertie-Alvin follow in the
next section of this summary covering the Northwest Australia/Southeast
Indian Ocean region.
*************************************************************************
NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E
Activity for November: 1 tropical LOW **
1 severe tropical cyclone ++
** - system moved into the Southwest Indian Ocean basin and was treated
as a cyclone of gale intensity by JTWC
++ - system moved into the Southwest Indian Ocean basin
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.
For portions of the systems' histories lying west of longitude
90E, the following applies:
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 Tropical Cyclone Advisory Centres in Mauritius and
Madagascar with longitude 55E being the demarcation line between their
respective areas of naming 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.
Northwest Australia/Southeast Indian Ocean
Tropical Activity for November
------------------------------------------
Two tropical systems formed in waters between 90E and 135E during the
month of November, both developing in the western part of the region and
subsequently moving westward across 90E into the Southwest Indian Ocean
basin. The first tropical LOW was unnamed by BoM Perth, but JTWC
upgraded it to tropical storm intensity and numbered it TC-02S. After
crossing 90E, RSMC La Reunion assumed official warning responsibility and
numbered it as Tropical Depression 04, but neither that agency nor
Mauritius considered it to be a tropical storm so it remained unnamed.
The second system was Severe Tropical Cyclone Bertie, the first cyclone
of the 2005-2006 to be named by any of the Australian TCWCs. Bertie
became quite an intense cyclone in the vicinity of the 90th meridian and
was renamed Alvin after crossing into the Southwest Indian Ocean proper.
The reports on TC-02S/MFR-04 and Bertie-Alvin follow in this section of
the summary since both originated east of 90E.
TROPICAL DEPRESSION
(MFR-04 / TC-02S)
5 - 8 November
---------------------------------------
During the opening days of November the daily STWOs issued by BoM
Perth began to hint of a weak LOW developing to the north and northwest
of the Cocos Islands. Around 0400 UTC on 4 November a weak 1006-mb LOW
was located about 230 nm north of the Cocos Islands and drifting south-
westward at 6 kts. A STWO issued by JTWC at 04/0900 UTC also mentioned
the system, noting that a tight LLCC was evident in animated multi-
spectral imagery with increasing convection showing signs of wrapping
into the center. The Perth TCWC initiated gale warnings on the LOW at
0400 UTC on 5 November, placing the center approximately 250 nm north
of the Cocos Islands. Gales were not occurring at the time, but the LOW
was forecast to develop into a tropical cyclone over the next 12 to 24
hours. JTWC issued a TCFA for the developing system at 05/0700 UTC.
The tropical LOW continued to move on the southwesterly track which it
would follow throughout its life. JTWC initiated warnings on TC-02S
at 05/1800 UTC, noting that the LOW was located within an environment of
moderate vertical shear with the deep convection remaining on the western
periphery of the exposed LLCC.
BoM Perth maintained the MSW at 30 kts while the system was located
within their AOR, while JTWC's 1-min avg MSW estimates reached a peak
of 45 kts at 06/0600 UTC with slow weakening thereafter. The minimum
CP as estimated by Perth reached 995 mb on their final warning, issued
at 06/1800 UTC. Normally a pressure this low is associated with a
tropical cyclone, and JTWC and SAB were assigning Dvorak ratings of
T3.0 on 6 November. It has occurred to the author that Perth's seeming
reluctance to name this system was perhaps in part due to the fact that
as it was about to cross 90E, it would be renamed, so it would almost
be like "wasting" a name to name it then. However, the LOW was beginning
to weaken as it crossed 90E, and neither MFR nor Mauritius regarded this
system as a tropical storm. Hence, no name was ever assigned to the
LOW, although it was designated Tropical Depression 04 by MFR. After
crossing into the Southwest Indian Ocean proper around 0000 UTC on
7 November at a point about 465 nm west-southwest of the Cocos Islands,
TD-04/TC-02S continued to march to the southwest as it slowly weakened.
MFR downgraded the system to a tropical disturbance at 08/0600 UTC, and
JTWC issued their final warning at the same time. MFR issued the final
warning on the system at 08/1200 UTC, placing the center around 800 nm
to the southeast of Diego Garcia.
A graphic depicting the track of this system may be found at the
following link:
No damage or casualties are known to have resulted from this system.
(Report written by Gary Padgett)
TROPICAL CYCLONE BERTIE-ALVIN
(MFR-05 / TC-03S)
18 - 28 November
-------------------------------------------------
What was to become the first intense tropical cyclone of the season
in the South Indian Ocean began as a weak tropical LOW on 17 November
at a very low latitude near 3.0S/94.0E. In anticipation of the LOW's
strengthening, BoM Perth began issuing gale warnings on the system at
0400 UTC on 18 November, placing the center approximately 575 nm north-
northwest of the Cocos Islands. A few hours later JTWC issued a STWO,
noting that convection was cycling around possible multiple LLCCs.
An 18/1335 UTC SSM/I pass as well as animated water vapor imagery
indicated the consolidation of the multiple LLCCs into a single center.
The LOW steadily increased in organization, and at 19/0000 UTC was
upgraded to Tropical Cyclone Bertie while located roughly 450 nm north-
northwest of the Cocos Islands. For the next several days Bertie tracked
southward and south-southwestward around the western periphery of a low
to mid-level anticyclone centered between northwestern Australia and
Sumatra.
After a rather sluggish start, intensification began to proceed at a
steady pace on the 20th with Bertie reaching severe tropical cyclone
status (hurricane intensity) by 21/0000 UTC. The cyclone's track at
this point became more southwesterly for about a day and a half before
swinging back to an almost due southerly course as it neared the 90th
meridian. The final warning from Perth was issued at 22/1200 UTC and
estimated the MSW at 85 kts. Warning responsibility was shifted to
MFR as it was anticipated that Bertie would have crossed 90E by the
next warning cycle. MFR assumed warning responsibility for Bertie at
22/1800 UTC with the center still located just east of longitude 90E.
The MSW was upped to its peak value of 100 kts with a CP of 930 mb.
(JTWC's peak 1-min avg MSW estimate was 115 kts at 23/0600 UTC.)
However, Bertie began to move due southward at this point with the
center remaining less than 20 nm east of 90E. Since MFR had already
assumed responsibility for issuing high seas warnings, they continued
to do so even though it was not until 24/0000 UTC that Bertie's center
finally edged west of the 90th meridian. Normally when a cyclone named
by Australia moves into the Southwest Indian Ocean basin, Mauritius
assigns a new name from the WMO Region I list of names, and a hyphenated
name is applied for a period of 24 hours following the crossing, after
which the Australian name is dropped. In the case of Bertie, Mauritius
did not rename the system Alvin until the center had crossed 90E at
24/0000 UTC, even though the WMO Region I RSMC (La Reunion) had been
issuing high seas warnings on the cyclone for more than a day.
After crossing into the Southwest Indian Ocean basin, Tropical
Cyclone Bertie-Alvin drifted to the southwest while slowly weakening.
By 24/1800 UTC the cyclone's center had reached a point approximately
490 west-southwest of the Cocos Islands. This was as far south as
Bertie-Alvin was to move--it then curved to a west-northwesterly course
which it followed for the remainder of its life. This track carried the
cyclone into an increasingly hostile environment of high vertical wind
shear, and weakening was fairly rapid after 25/0000 UTC. The MSW was
estimated at 80 kts at that hour--six hours later it was lowered to
55 kts. MFR reduced Tropical Storm Alvin to tropical depression status
at 1200 UTC on 26 November and to a 25-kt tropical disturbance at 1800
UTC on the 27th. The weakening was even more dramatic based upon JTWC's
warnings: at 24/1800 UTC that agency's 1-min avg MSW was still 100 kts.
The final JTWC warning, issued 30 hours later, reduced the intensity to
30 kts. The La Reunion TCWC continued to issue warnings on ex-Tropical
Storm Alvin through 28/1200 UTC when the final bulletin placed the
weak center about 685 nm east-southeast of Diego Garcia.
A graphic depicting the track of Tropical Cyclone Bertie-Alvin may
be found at the following link:
No damage or casualties have been attributed to Tropical Cyclone
Bertie-Alvin.
(Report written by Gary Padgett)
*************************************************************************
NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E
Activity for November: No tropical cyclones
*************************************************************************
SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E
Activity for November: No tropical cyclones
*************************************************************************
SPECIAL FEATURE - SOURCES OF TROPICAL CYCLONE INFORMATION
The purpose of this section is to list some websites where many and
varied types of tropical cyclone information are archived. Many readers
will know about these already, but for the benefit of those who don't,
I wanted to include them.
(1) Aircraft Reconnaissance Information
---------------------------------------
Various types of messages from reconnaissance aircraft may be
retrieved from the following FTP site:
Information regarding how to interpret the coded reconnaissance
messages may be found at the following URL:
Links are also included to websites with further information about the
U. S. Air Force 53rd Weather Reconnaissance Squadron and the NOAA Air-
craft Operations Center.
(2) Archived Advisories
-----------------------
All the advisory products (public advisories, forecast/advisories,
strike probabilities, discussions, various graphics) issued by TPC/NHC
are archived on TPC's website. For the current year (using 2004 as an
example), the archived products can be found at:
Links to tropical products archives for earlier years are available at
the following URL:
JTWC warnings for past storms are archived on the NRL Monterry website:
On the NRL site, the link to past years can be found in the upper left
corner of the screen.
I am not aware at the moment of any other TCWC which archives all
its tropical cyclone warning/advisory products for public access, but
if I learn of any, I will add them to this list.
(3) Satellite Imagery
---------------------
Satellite images of tropical cyclones in various sensor bands are
available on the NRL Monterrey and University of Wisconsin websites,
courtesy of Jeff Hawkins and Chris Velden and their associates. The
links are:
On the NRL site, the link to past years can be found in the upper left
corner of the screen. For the CIMSS site, a link to data archives is
located in the lower left portion of the screen.
Additional tropical satellite imagery, along with looping ability for
composite microwave imagery for the Western Hemisphere north of the
equator, can be found at:
(1) For the Eastern North Pacific:
(2) For the Atlantic, Gulf of Mexico and Caribbean Sea:
I'm sure there are other sites with available imagery available, and
as I learn of them, I will add the links to this list.
*************************************************************************
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 August, 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, Chris
Landsea, and John Diebolt):
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:
TROPICAL CYCLONE REPORTS AVAILABLE
JTWC now has available on its website the Annual Tropical Cyclone
Report (ATCR) for 2004 (2003-2004 season for the Southern Hemisphere).
ATCRs for earlier years are available also.
Also, TPC/NHC has available on its webpage nice "technicolor"
tracking charts for the 2004 Atlantic and Eastern North Pacific
tropical cyclones; also, storm reports for all the 2004 Atlantic
and Eastern North Pacific cyclones are now available, as well as
track charts and reports on storms from earlier years.
A special thanks to Michael Bath of McLeans Ridges, New South Wales,
Australia, for assisting me with proofreading the summaries.
PREPARED BY
*************************************************************************
*************************************************************************
Posted: 03.27.06 / Typhoon2000.ph, Typhoon2000.com