MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY
MAY,
2006
(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.)
IMPORTANT NOTE FROM THE AUTHOR -- PLEASE READ!!!
In order for the tropical cyclone summaries to
continue with any
degree of timeliness, some changes are going to be
necessary in order
to significantly reduce the amount of time required
to prepare them. I
have many commitments and demands made upon
my time, and to be honest,
I just do not have the enthusiasm I once
had for writing them. I find
it increasingly difficult to
spend hours poring over discussions and
warnings just to glean a few
tidbits of information here and there to fit
into a historical
narrative. However, so many persons have told me,
and continue to tell me, that they find the summaries and track files
useful, so I do not want to completely drop them. Some
streamlining
of the narratives detailing the synoptic history of the
storms will be
made for cyclones in all the basins, but there is
going to be a
significant reduction in the coverage given to Atlantic
and Northeast
Pacific tropical cyclones.
While these basins are personally my primary
basins of interest (I
live less than 100 km from the Gulf of Mexico),
I am reducing coverage
of these tropical cyclones for several
reasons:
(1) A significant majority of the readers of these summaries live in
the
United States, and Atlantic (and usually
Eastern Pacific) storms are
given wide
coverage on the Atlanta-based Weather Channel as well
as
various other 24-hour TV cable news
providers.
(2) Many persons outside the U. S. are also able to watch the cable
news
channels and follow Atlantic cyclones in
particular.
(3) Tropical cyclone warnings can be received via e-mail or
downloaded
from websites from just about every
warning agency in the world, and
any person
interested in performing detailed research on any
cyclone
can save these warnings for further
study if they so desire. In
addition, TPC/NHC archives all their tropical cyclone
advisories,
discussions and graphics on their
website, and these are available
long-term
for any person who desires to research a particular
cyclone
in greater detail.
(4) In addition to the narrative summaries, from the beginning I
have
prepared a tabular track file to
accompany each month's summary.
These give a
concise and quantitative history of each cyclone,
and
in conjunction with the graphics which
John Diebolt of Tucson is now
preparing based
upon these track files, present a very
adequate
numerical and pictorial
representation of each cyclone's history.
(A
picture is worth a thousand words!) Beginning with
December,
2004, I have been including the link
to each cyclone's track graphic
on John's
website. (For more information on John's website,
see
the Feature of the Month article in the
February, 2005, summary.)
(5) I have discovered an online encyclopedia (Wikipedia) which
contains
fairly detailed reports of tropical
cyclones, especially for Atlantic
storms. I have included links to these reports already for
several
storms and plan to continue doing
so. I have recently been in
contact with
one of the authors and managers of the
Wikipedia
tropical cyclone project, and plans
are for these reports to continue
to exist
and grow in scope and remain available long-term.
(6) And finally, TPC/NHC has their extremely informative storm
reports
available online beginning usually in
late October (sometimes
earlier), and for the
most part completed by the end of the calendar
year. Indeed, ever since the 2000 season the official NHC
reports
have begun appearing before I could
get the preliminary reports
completed for many
of the latter cyclones each season, so I chose
instead to write just a brief article supplementing the
official
reports for those cyclones.
I hope those who are primarily interested in
Atlantic cyclones will
not be too disappointed, but this is a
necessary step to insure that
reports on cyclones in other basins for
which information is not so
readily available will not be running
months behind, as has often been
the case in the past.
Also, Kevin Boyle and Simon Clarke have assured me
that they are
still interested in writing tropical cyclone reports for
the Western
North Pacific, Northeast Australia/Coral Sea and South
Pacific basins,
so summaries for storms in those basins should
continue with little
change.
*************************************************************************
MAY HIGHLIGHTS
--> Rare South China Sea super typhoon has adverse effects
on several
southeastern Asian
nations
--> First Eastern North Pacific tropical storm forms
on schedule
*************************************************************************
ACTIVITY BY BASINS
ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of
Mexico
Activity for May: No tropical cyclones
*************************************************************************
NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude
180
Activity for May: 1 tropical storm
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 (or the
Central Pacific Hurricane Center (CPHC) in
Honolulu, Hawaii, for
locations west of longitude 140W):
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.
Northeast Pacific Tropical Activity for
May
-------------------------------------------
In recent years the tropical cyclone season in the
Northeast Pacific
basin has begun almost like clockwork within the
latter 10 days of May,
and 2006 was no exception. The
first tropical depression (01E) formed
on 27 May and later that same
day became Tropical Storm Aletta. Over
the period 1971-2005, the
month of May has averaged about one storm
every other year, but 2006
was the seventh consecutive season in which
the first named storm has
formed in May. By way of contrast, the 8-year
period 1992
through 1999 saw only one May tropical storm develop--an
unnamed storm
in 1996. The only May in which two Eastern Pacific storms
developed was in 1984. Aletta produced 2.25 NSD--the average NSD for
May
is 1.84 for the 35-year period. A short report on Aletta
follows.
TROPICAL STORM
ALETTA
(TC-01E)
27 - 30
May
-----------------------------------------
Most of the information in this short report was
obtained from the
monthly summary for May prepared by the staff of
TPC/NHC. Tropical
Storm Aletta represents the seventh
consecutive year in which the
Eastern North Pacific tropical cyclone
season has begun in the month of
May, a month which normally sees a
tropical storm or hurricane form only
about every other year.
Aletta formed as a result of the interaction of a
westward-moving
tropical wave with a low-level trough near the Gulf of
Tehuantepec. The
resultant broad low-pressure area was located
several hundred miles
south of Acapulco on 25 May. Organization
gradually increased and the
system had developed into Tropical
Depression 01E by early on the 27th,
centered about 165 nm southwest
of Acapulco. The depression embarked on
a northerly track toward
the Mexican coast and was upgraded to Tropical
Storm Aletta later that
same day. Aletta's peak intensity of 40 kts was
attained at 0600
UTC on 28 May and was maintained for 36 hours. The
tropical cyclone moved erratically, executing a counterclockwise loop
southwest of Acapulco on the 28th. A strengthening ridge to the
north
prevented a rendezvous with the Mexican coastline and Aletta
began
drifting westward on the 29th while slowly weakening to a
depression
by 30/0000 UTC. Aletta continued to weaken and
dissipated about 170 nm
south-southeast of Manzanillo later on the
30th.
Aletta produced some locally heavy rains over
portions of southern
Mexico with a 24-hour total of 91 mm in Oaxaca
State. No damage nor
casualties were reported.
A graphic displaying the track of Tropical Storm
Aletta may be found
at the following link:
The track in tabular form may be accessed at the
following URL:
The link for the online Wikipedia report on Aletta
is:
*************************************************************************
NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude
180
Activity for May: 1 super typhoon
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.
SUPER TYPHOON
CHANCHU
(TC-02W / TY 0601 /
CALOY)
8 - 20 May
----------------------------------------------
Chanchu: contributed by the colony of Macau, is the Macanese word
for
pearl
A. Introduction
---------------
The second significant tropical cyclone of 2006 in
the NW Pacific
basin, Chanchu became the earliest system to be
designated a super
typhoon by JTWC in the South China Sea.
Super typhoons are a rarity in
that part of the world, and a search
through the JTWC archives reveal
that the only other tropical
cyclones to reach that intensity in the
South China Sea were Ryan
(1995) and Sally (1996).
From its formation late on 8 May Chanchu crossed
the Philippine
Archipelago on 11-12 May before peaking at 135 kts in
the South China
Sea early on 15 May. After alarming the
community of Hong Kong, China,
Chanchu veered sharply away towards
the north and made landfall in
Guangdong Province in eastern China on
17 May.
B. Synoptic History
-------------------
Super Typhoon Chanchu began its life as a
persistent area of
convection approximately 310 nm southeast of
Yap. It was first noted in
JTWC's STWO issued at 2030 UTC 5
May. The tropical disturbance remained
a weak, poorly-organized
feature until 7 May when the system's
organization began to improve
and the LLCC began to consolidate. A TCFA
was issued at 08/1100
UTC, relocating the disturbance to a position
approximately 100 nm
west-southwest of Yap. The first warning on
Tropical Depression
02W was issued at 08/1800 UTC with the system at this
time passing
north of Palau. TD-02W was upgraded to a 35-kt tropical
storm
at 09/0000 UTC, and acquired the name Chanchu at 09/1200 UTC when
JMA
raised their 10-min avg MSW to 35 kts.
Tropical Storm Chanchu continued to intensify as
it tracked
predominantly west-northwestward along the southern
periphery of a
subtropical ridge. It was upgraded to a 75-kt
typhoon at 1800 UTC
10 May while centred approximately 440 nm
east-northeast of Zamboanga,
Philippines. Typhoon Chanchu
weakened slightly as it crossed the
northern tip of Samar,
Philippines, on 11 May. However, despite the
hindering effects
of land, Chanchu re-strengthened while over the
Sibuyan Sea on 12
May. The storm's intensity fluctuated as it tracked
erratically
westward across the Philippine island of Mindoro, emerging
into the
South China Sea early on 13 May where it slowly began to
reorganize. The tropical cyclone was forecast in the long-term to
become very intense and to make landfall in the vicinity of Hong
Kong,
China.
Drifting westwards, Typhoon Chanchu underwent
rapid intensification
over the South China Sea on 14 May. It
was upgraded to a super typhoon
at 1800 UTC 14 May while located
approximately 515 nm south of Hong
Kong, China, before peaking at 135
kts six hours later. Chanchu
abruptly veered north on 15 May as
the subtropical ridge split apart,
and this northward path into the
resulting weakness took the storm into
a less favourable
environment. At 15/0600 UTC Chanchu was downgraded
back to
typhoon intensity. The tropical cyclone gradually weakened
further but remained a powerful system for the next two days while
moving on a north to north-northeasterly trajectory through the South
China Sea towards the Chinese coast, away from Hong Kong. The
typhoon made landfall near Shantou, Guangdong Province, late on 17
May
with the MSW estimated at 75 kts. Chanchu continued up the
eastern
coastal region of China and was downgraded to a 45-kt
tropical storm on
JTWC's final warning at 18/0000 UTC. JMA also
downgraded Chanchu to a
tropical storm at this time but continued to
issue bulletins until it
was declared extratropical over the East
China Sea at 19/0000 UTC. The
weak residual LOW continued
northeastward, passing over the Japanese
islands of Kyushu, Shikoku
and Honshu, eventually exiting into the
North Pacific near
Tokyo.
The highest MSW estimated by JMA was 90 kts with a
minimum CP of
930 mb. PAGASA estimated a peak intensity of 80
kts while Typhoon
Chanchu/Caloy was within their AOR. PAGASA
first assigned the name
Caloy at 09/0000 UTC after the system had
crossed 135E.
A graphic displaying the track of Super Typhoon
Chanchu/Caloy may be
found at the following link:
The track in a tabular format may be accessed at
the following URL:
C. Damage and Casualties
------------------------
Typhoon Chanchu was responsible for 41 deaths in
the Philippines,
including 21 persons who perished when a motor boat
capsized off
Masbate Island. In China, at least twenty-five
people were reported
dead with four missing. Eleven fishing
vessels from Vietnam were sunk,
killing 44 fishermen, and at least
190 Vietnamese were reported
missing. The above casualty
information, along with a much more
detailed description on the impact
of Super Typhoon Chanchu, may be
obtained at the following link:
(Report written by Kevin Boyle)
*************************************************************************
NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea
Activity for May: No tropical cyclones
*************************************************************************
SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude
90E
Activity for May: No tropical cyclones
*************************************************************************
NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to
135E
Activity for May: No tropical cyclones
*************************************************************************
NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E
Activity for May: No tropical cyclones
*************************************************************************
SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude
160E
Activity for May: 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: 08.18.06 / Typhoon2000.ph, Typhoon2000.com
