MONTHLY GLOBAL TROPICAL CYCLONE SUMMARY
APRIL, 2007
(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.)
SPECIAL NOTE #1: John Diebolt of Tucson, Arizona, produces track
graphics of all the tropical and subtropical systems for which I prepare
a tabular track in the companion cyclone tracks file. These can be
accessed at the following URL:
http://www.tropicalcyclone2005.com/
Scroll down the chart to the month of interest and click on the green
bar under "Operational Track Image" for the desired system.
The tabular track of positions and intensities may also be obtained
from the above website, or from the other archival sites listed in
the Author's Note in the closing section of this summary.
SPECIAL NOTE #2: Short reports with satellite pictures and small-scale
maps for all tropical cyclones may be found at the following links:
http://en.wikipedia.org/wiki/2007_Atlantic_hurricane_season
http://en.wikipedia.org/wiki/2007_Pacific_hurricane_season
http://en.wikipedia.org/wiki/2007_Pacific_typhoon_season
http://en.wikipedia.org/wiki/2007_North_Indian_cyclone_season
http://en.wikipedia.org/wiki/2006-07_Southern_Hemisphere_tropical_cyclone_se
ason
*************************************************************************
APRIL HIGHLIGHTS
--> Cyclone strikes northeastern Madagascar
--> First Northwest Pacific typhoon of year affects Marianas
--> South Pacific tropical cyclone causes damage in Fiji
*************************************************************************
********** EXTRA FEATURE **********
WESTERN HEMISPHERE TROPICAL CYCLONE NAMES for 2007
Tropical cyclones in the Atlantic Ocean, Gulf of Mexico, and
Caribbean Sea are assigned names by the Tropical Prediction Center/
National Hurricane Center in Miami, Florida. A separate alphabetical
set of alternating male/female names is used each year with the name
of the first tropical storm beginning with the letter "A". Names are
repeated every six years. The names of hurricanes which cause a lot
of damage and/or fatalities are usually retired from the list with
another name of the same alphabetical rank and gender replacing it.
Following the 2006 season, which was a mild one, no names were retired
so the list for 2012 will be identical to last year's list.
The highest number of tropical storms named in one season in the
Atlantic was 27 during the incredibly active 2005 season, which has
become the most active Atlantic tropical cyclone season on record.
Other very active seasons include 1887 (19 storms), 1933 (21 storms),
1969 (18 storms) and 1995 (19 storms).
The list of names for 2007 is the same one used during the active
hurricane season of 2001 when fifteen tropical cyclones were named,
down through Olga. Names retired following 2001 include Allison,
Iris, and Michelle, and these have been replaced in the list for 2007
with Andrea, Ingrid, and Melissa, respectively.
TPC/NHC also has warning responsibility for the Eastern North
Pacific Ocean from the west coast of Mexico out to longitude 140W.
Six separate alphabetical sets of names are used for this basin in
the same manner as in the Atlantic. Initially, the Eastern Pacific
name sets contained only 21 names, omitting "Q" and "U" and ending
with the letter "W", as in the Atlantic. When the active 1985 season
threatened to exhaust the list, the names Xina, York and Zelda were
drafted to accommodate any additional storms which might develop.
(Hurricane Xina was named in late October, 1985.) The decision was
made sometime in the latter 1980s to extend the list with these three
names in odd-numbered years, and to add the names Xavier, Yolanda and
Zeke in even-numbered years (to preserve the alternating gender
scheme). During the Northeast Pacific's year of record activity in
1992, all 24 names were allotted to tropical cyclones forming east of
140W, ending with Tropical Storm Zeke in late October. Had more storms
developed, they would have been named with the letters of the Greek
alphabet (Alpha, Beta, etc), which is also the backup plan for the
Atlantic basin in case more than 21 tropical storms develop in a single
season.
The list for this year was last used in 2001 when fifteen tropical
cyclones were named, the last one being Octave. The most active season
to utilize this set of names was in 1983, when 21 cyclones were named,
down through Winnie (later changed to Wallis). Following the 2001
season, the name Adolph was retired for political considerations and
replaced with Alvin in the list for 2007.
The Central Pacific Hurricane Center, located in Honolulu, has
tropical cyclone warning responsibility for that portion of the North
Pacific Ocean lying between longitudes 140W and 180. The majority of
the tropical storms and hurricanes seen in that region are visitors
from east of 140W, but on the average about one tropical storm forms
in the Central Pacific each year, and when this happens, the storm is
given a Hawaiian name. The list consists of four sets of twelve
names each, using only the letters of the Hawaiian alphabet. All the
names are used--the first storm to form in a given year is assigned
the next available name on the list. No tropical cyclones were named
by CPHC in 2003-2005. The last storm to form in Central Pacific
waters was Hurricane Ioke in August, 2006, so the next name to be
assigned will be Kika.
The list of Hawaiian names has recently been revised with 16 of
the 48 names having been replaced. In the column of names listed below
for the Central Pacific, the names Omeka, Pewa and Unala are new,
replacing Oleka, Peni and Ulia.
Names for 2007 are (** indicates name has already been assigned):
ATLANTIC EASTERN PACIFIC CENTRAL PACIFIC
Andrea ** Lorenzo Alvin ** Manuel Kika
Barry ** Melissa Barbara ** Narda Lana
Chantal Noel Cosme Octave Maka
Dean Olga Dalila Priscilla Neki
Erin Pablo Erick Raymond Omeka
Felix Rebekah Flossie Sonia Pewa
Gabrielle Sebastien Gil Tico Unala
Humberto Tanya Henriette Velma Wali
Ingrid Van Ivo Wallis Ana
Jerry Wendy Juliette Xina Ela
Karen Kiko York Halola
Lorena Zelda Iune
*************************************************************************
ACTIVITY BY BASINS
ATLANTIC (ATL) - North Atlantic Ocean, Caribbean Sea, Gulf of Mexico
Activity for April: No tropical cyclones
Atlantic Tropical Activity for April
------------------------------------
The only April tropical or subtropical storms included in the Atlantic
basin's official "best tracks" database are a subtropical storm in 1992
and Tropical Storm Ana in 2003, which initially was a subtropical storm.
And April, 2007, was a normal month in that no systems were tracked.
However, there was one system which did elicit some interest. On
20 April, exactly four years to the day after Ana was named as a
subtropical storm, visible satellite imagery revealed what at first
glance looked like a well-developed tropical or subtropical storm
east of the northern Florida coastline with a large, ragged hole in
the middle which sort of resembled an eye. Buoy reports indicated the
existence of a surface circulation, but the convection was extremely
shallow and the system did not show up in large-scale water vapor
imagery. The LOW apparently had its roots in a large mid to upper-level
tropospheric cyclone which had been south of Lake Michigan on the 18th
and had migrated across the Appalachians on its way to the Atlantic.
So, while the system was interesting-looking, nothing came of it.
*************************************************************************
NORTHEAST PACIFIC (NEP) - North Pacific Ocean East of Longitude 180
Activity for April: No tropical cyclones
*************************************************************************
NORTHWEST PACIFIC (NWP) - North Pacific Ocean West of Longitude 180
Activity for April: 1 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.
Northwest Pacific Tropical Activity for April
---------------------------------------------
A tropical depression which formed at the end of March became the
first tropical storm and first typhoon of 2007 in the Northwest Pacific
basin. Typhoon Kong-rey intensified into a typhoon of moderate intensity
(Category 2 on the Saffir/Simpson scale) and passed through the Mariana
Islands but fortunately caused no fatalities and only minor damage. A
report on Kong-rey, written by Kevin Boyle, follows.
TYPHOON KONG-REY
(TC-01W / TY 0701)
31 March - 7 April
--------------------------------------
A. General Information
----------------------
1. Identification
a. RSMC - Japanese Meteorological Agency, Tokyo (JMA)
b. JMA - Typhoon 0701
c. JTWC - Tropical Cyclone 01W
d. NAME - Kong-rey (named by JMA at Mar 31/1800 UTC; name
contributed to the regional list by Cambodia, and
is the name of a pretty girl in a Khmer legend;
also the name of a mountain)
2. Overview
a. Basins Affected: Northwest Pacific Ocean (NWP)
b. Dates: 31 March - 7 April, 2007
c. Max Sust Winds: 90 kts (1-min avg per JTWC)
75 kts (10-min avg per JMA)
d. Min Cent Press: 960 hPa (estimate per JMA)
3. Beginning of Track: Mar 31/0000 UTC, near 7.0N/157.0E, or about
75 nm west of Phonpei, as referenced in a High Seas bulletin
issued by JMA.
4. Peak Intensity: Apr 03/1200 UTC, near 17.7N/144.3E, or about
175 nm north-northwest of Saipan. (It should be noted that JTWC's
MSW was at 90 kts from 03/1200 through 04/0000 UTC.)
5. Size: At its peak Typhoon Kong-rey was a moderately small tropical
cyclone with a gale radius averaging between 80-90 nm.
6. End of Track: Apr 07/0000 UTC, near 27.0N/169.0E, or about 475 nm
north-northeast of Wake Island.
B. Synoptic History
-------------------
1. Origin: The precursor to Typhoon Kong-rey was initially discussed in
JTWC's STWO issued at 1400 UTC 30 March. A TCFA was issued at
31/0600 UTC based on increased consolidation of the LLCC and a 24-hour
pressure fall of nearly 4 mb at Pohnpei. Upper-level analysis
indicated a region of moderate vertical shear but excellent
equatorward outflow and improving poleward outflow due to a deepening
upper-level LOW located near 179E.
2. General Description of Track: Tropical Depression 01W formed west
of Pohnpei on 31 March and tracked west-northwestward south of a
subtropical ridge, reaching tropical storm intensity late on 31 March
while located approximately 150 nm east-northeast of Chuuk. Kong-rey
turned northwestward and became a typhoon on 2 April, passing a little
over 40 nm east-northeast of Saipan at around 02/2200 UTC. After
attaining its peak intensity of 90 kts on 3 April, Kong-rey turned
northwards into a weakness in the ridge instigated by a deepening mid-
latitude trough. The storm then recurved northeastward into the
westerlies the next day and weakened rather quickly, becoming
extratropical on 6 April. The extratropical gale continued to weaken
and by 0000 UTC 7 April was only a 20-kt LOW located about 475 nm
north-northeast of Wake Island.
An excellent comprehensive online report on Typhoon Kong-rey may be
found at the following link:
http://en.wikipedia.org/wiki/Typhoon_Kong-rey_%282007%29
C. Meteorological Data
----------------------
1. The highest wind gust reported on Saipan was 36 kts at 03/0641 UTC.
Sustained winds remained below gale force.
2. A ship located 45 miles east of the centre at 04/1800 UTC reported
1001 mb and a south-southeast wind of 45 kts.
3. The centre of Typhoon Kong-rey passed about 20 miles northwest of a
buoy which reported 994 mb at 2000 UTC (down from 1008 mb at 1200
UTC), putting the MSLP in the 988-990 mb range. (I do not have the
exact time of the observation.)
4. Minamitorishima (station 47991, RJAM) reported 1003.7 mb and 36 kts
at a 9-metre elevation at 05/0700 UTC with the centre of Kong-rey
located about 110 miles to the northwest. Extratropical transition
was complete or nearly complete at this time.
The above observations were sent to the author by Derrick Herndon. A
special thanks to Derrick for sending the information.
Some additional observations are contained in the Wikipedia report
(see link above).
D. Damage and Casualties
------------------------
There were no casualties nor major damage associated with Typhoon
Kong-rey.
E. Additional Discussion
------------------------
Many of the global models predicted tropical cyclogenesis in the
tropical Western North Pacific for almost a week before the emergence
of Kong-rey. Following are some comments from Chris Velden which he
posted to a tropical cyclone discussion group on 30 March shortly
before the development of Tropical Depression 01W. (Thanks to Chris
for giving me permission to include his comments here.)
"I think what we now see unfolding in the WestPac is quite remarkable.
"Neglecting for a moment that a definite TC hasn't popped out yet from
the large gyre, the fact that a strong cyclonic system has quickly
emerged in the predicted region from global model forecasts over a
week ago is testament to just how far we have come, IMHO. As a TC
research group we harp over the chaotic dynamics in that part of
the tropics, with all the various scale interactions and complexities.
But it appears that we are beginning to capture some of Nature's
secrets through our computational advances, improved physics and
parameterizations, and better assimilation of satellite data. This is
indeed a success story worthy of accolades for the NWP groups and the
R&D communities that have supported the model developments over the
past two decades. Just a few years ago we may have seen this 7-10 day
model forecast of TC genesis and shrugged our shoulders as a likely
false alarm. Now, we take a serious notice, especially when there is
a consensus solution, we then look for verification and, quite often,
find it.
"The global models will not always get it right these days, but I
think we need to remember where we were just a few years ago in TC
genesis prediction, and take our hats off to the NWP and data
assimilation communities for the progress that has been made."
(Report written by Kevin Boyle with Section E added by Gary Padgett)
ADDENDA TO NOVEMBER, 2006, SUMMARY
----------------------------------
At the time the November, 2006, summary was posted, Michael V. Padua
of Naga city, Philippines, did not have all the data from his weather
station recorded during Super Typhoon Durian collected and ready to
send me. He has subsequently sent the information to me, but I forgot
to include it in the March summary, so here it is:
=========================================================================
T2K Weather Station Extreme Observations
Name: Super Typhoon Durian (Reming)
Date: November 30, 2006
Source: Davis Vantage Pro 2004 Version
+Highest Wind speed recorded: 189.9 km/hr (NE) @ 3:46 pm (07:46 utc)
Nov 30.
+Highest 10-min. Wind Average: 125.5 km/hr (NORTH) @ 3:26 pm (07:26 utc)
Nov 30.
+Lowest Barometric Pressure (from 4:00 pm to 4:14 pm Nov 30): 962 hPa*
+ Rainstorm** (Nov 29-30, 2006 / 48 hour-reading): 7.19 inches
(182.6 mm)
+ 24-hour Rainfall (Nov 30, 2006 / 12am to 12am): 6.15 inches
(156.2 mm)
+ Highest Rain Rate (Nov 30, 2006 / 3:11pm to 3:12 pm): 41.1 inches
(1,045 mm)***
Note: * STY Durian's 962 hPa - was the lowest barometric pressure I have
ever observed since STY Nina (Sisang) of Nov 26, 1987, which was
my first typhoon observation.
** The data ended around 5:35pm when my rain gauge fell on the
ground...so the rainfall may have reached more than 200 mm over
Naga City. The rain stopped pouring around 10pm or 5 hours later.
*** This is the highest rain rate my Davis Vantage Pro recorded since
I installed the unit on July 24, 2004.
Complete Raw Data:
http://www.typhoon2000.ph/stormarchives/2006/observations/reming_raw_obs.htm
Wind/Pressure Graphic Observation:
http://www.typhoon2000.ph/stormarchives/2006/observations/Durian_t2kobs_grap
h.gif
*************************************************************************
NORTH INDIAN OCEAN (NIO) - Bay of Bengal and Arabian Sea
Activity for April: No tropical cyclones
*************************************************************************
SOUTHWEST INDIAN OCEAN (SWI) - South Indian Ocean West of Longitude 90E
Activity for April: 1 subtropical depression
1 intense tropical cyclone **
** - system formed in March and was covered in March summary
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 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.
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 April
--------------------------------------------------
As the month of April opened Intense Tropical Cyclone Jaya was headed
for northern Madagascar. The storm made landfall there on the 3rd, but
very fortunately had weakened to minimal cyclone (i.e., hurricane)
intensity by the time it came ashore. The report on Jaya can be found
in the March summary. A system of initially non-tropical origin formed
in the western Mozambique Channel during the second week of the month and
ultimately developed into a subtropical storm. A short report on this
system follows. Other than these two systems, the Southwest Indian Ocean
remained quiet during the month of April.
SUBTROPICAL DEPRESSION
(MFR-15)
9 - 12 April
------------------------------------------
A. General Information
----------------------
1. Identification
a. RSMC - Meteo France La Reunion (MFR)
b. MFR - Subtropical Disturbance 15
2. Overview
a. Basins Affected: Southwest Indian Ocean (SWI)
b. Dates: 9 - 12 April, 2007
c. Max Sust Winds: 45 kts (10-min avg per MFR)
d. Min Cent Press: 998 hPa (estimate per MFR)
3. Beginning of Track: Apr 09/1200 UTC, near 21.7S/36.9E, or about
160 nm southeast of Beira, Mozambique.
4. Peak Intensity: Apr 11/1200 UTC, near 29.7S/39.6E, or about 450 nm
east of Durban, South Africa. (It should be noted that MFR's MSW
was at 45 kts from 11/1200 through 12/0000 UTC.)
5. Size: At its peak Subtropical Depression 15 was a rather small
system, with gales estimated to extend outward only 50 nm from the
center.
6. End of Track: Apr 12/1200 UTC, near 36.0S/46.0E, or about 850 nm
east-southeast of Durban, South Africa.
B. Discussion
-------------
RSMC La Reunion (MFR) issued a warning at 1200 UTC on 11 April for
a system they had classified as Subtropical Depression 15, located about
450 nm east of Durban, South Africa. The MSW was estimated at 45 kts
with the system moving southward at 15 kts. While this was the first
operational warning, a post-storm track available on MFR's website
traces the system to a disturbance which at 1200 UTC on 9 April was
located off the coast of Mozambique about 160 nm southeast of Beira.
The LOW initially moved east-southeastward, gradually curving to the
southeast and south and passing a short distance west of Europa Island
on the 10th. The post-storm track classifies the system as a 30-kt
tropical depression at 10/1800 UTC, and as a 35-kt subtropical depression
at 11/0000 UTC while located approximately 300 nm southwest of Toliara,
Madagascar.
The 45-kt MSW in the first warning turned out to be the system's peak
intensity. Following the issuance of the first warning at 11/1200 UTC,
Subtropical Depression 15 began to accelerate off to the south-southeast,
gradually weakening as it began to undergo extratropical transition. The
fourth and final MFR warning, issued at 12/1200 UTC, classified the
system as extratropical and placed the center about 850 nm east-southeast
of Durban, moving southeastward at 23 kts.
This system formed in the Mozambique Channel at the same time that the
remnant LOW from former Intense Tropical Cyclone Jaya was still present
west of northern Madagascar, which led to some speculation that the
subtropical system was a possible redevelopment of Jaya. According to
Philippe Caroff of RSMC La Reunion, this was not the case. Subtropical
Depression 15's precursor formed on the western side of the Channel
with the very weak remnant of Jaya to the northeast being absorbed
into the developing system to the west.
(Note: For subtropical systems MFR uses the term 'subtropical depression'
for systems above gale force, even up to hurricane intensity, such as
Subtropical Depression Luma in April, 2003, with maximum winds estimated
at 65 kts. As for why Subtropical Depression 15 was not named, I do not
know, but since Madagascar has naming responsibility for systems in the
Southwest Indian Ocean west of 55E, my guess would be that they did not
consider the system as qualifying for a name.)
C. Meteorological Data
----------------------
I have a couple of observations from Derrick Herdon on this system
(a thanks to Derrick for sending them along). As the developing system
passed west of Europa Island on the 10th, the station there reported
a minimum MSLP of 1006 mb. Also, Subtropical Depression 15 passed over
a buoy (14912) around 0200 UTC on 12 April, with the pressure having
fallen from 1020 mb 24 hours earlier to 1002 mb. The center was near
latitude 34S by that time so extratropical transition was likely well
underway.
(Report written by Gary Padgett)
*************************************************************************
NORTHWEST AUSTRALIA/SOUTHEAST INDIAN OCEAN (AUW) - From 90E to 135E
Activity for April: No tropical cyclones
*************************************************************************
NORTHEAST AUSTRALIA/CORAL SEA (AUE) - From 135E to 160E
Activity for April: No tropical cyclones
*************************************************************************
SOUTH PACIFIC (SPA) - South Pacific Ocean East of Longitude 160E
Activity for April: 1 tropical cyclone of storm intensity
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 April
-----------------------------------------
Tropical cyclone activity in the South Pacific basin east of 160E
during the 2006-2007 season has been arranged into three well-defined
periods separated by a month or more of quietude. The first period
began with the formation of Tropical Depression 01F on 20 October,
which became the intense Tropical Cyclone Xavier. Weak depressions
02F and 03F followed in late October/early November, followed by
Tropical Cyclone Yani (04F) during the latter part of November. This
first spurt of activity ended with Tropical Depression 05F (TC-04P
per JTWC) which had dissipated by 4 December. The tropical South
Pacific lay depression-free the remainder of December and through the
first week of the new year.
The formation of Tropical Depression 06F during the second week of
January heralded the advent of the second period of activity. TD-06F
was quickly followed by the southeasterly "shooters" Tropical Cyclones
Zita (07F) and Arthur (08F) with both almost reaching hurricane
intensity. This second round of activity was capped off by Tropical
Depression 09F, treated as TC-11P by JTWC, during early February. This
system had dissipated by 5 February, and no depressions or cyclones
stirred South Pacific waters until late in the third week of March.
The third spurt of tropical cyclone activity began with the formation
of Tropical Depression 12F on 21 March, and continued with Tropical
Cyclone Becky (13F) during the closing days of March, another system
which flirted with hurricane intensity (it was so classified by JTWC).
This final (as of 8 June) round of storms concluded with Tropical Cyclone
Cliff during the first week of April, a system which brought some strong
winds and heavy rainfall to Fiji during its formative stages. A report
on Cliff, authored by Simon Clarke, follows.
TROPICAL CYCLONE CLIFF
(TD-14F / TC-23P)
3 - 6 April
------------------------------------------
A. General Information
----------------------
1. Identification
a. RSMC - Nadi, Fiji/Wellington, New Zealand, TCWCs
b. Fiji - Tropical Disturbance 14F
c. JTWC - Tropical Cyclone 23P
d. NAME - Cliff (named by Fiji at 04 Apr/0300 UTC)
2. Overview
a. Basins Affected: South Pacific Ocean (SPA)
b. Dates: 3 - 6 April, 2007
c. Max Sust Winds: 50 kts (10-min avg per Fiji)
55 kts (1-min avg per JTWC)
d. Min Cent Press: 980 hPa (estimate per Fiji)
3. Beginning of Track: Apr 03/0600 UTC, near 14.7S/176.5E, or about
215 nm north-northwest of Suva, Fiji, as referenced in initial
tropical disturbance summary issued by Nadi.
4. Peak Intensity: Apr 05/0600 UTC, near 21.2S/177.3W, or about 125 nm
west of Nuku'alofa. (It should be noted that Fiji's MSW was at
50 kts from 05/0600 through 06/0600 UTC.)
5. Size: Based on Fiji's warnings, at its peak Tropical Cyclone Cliff
was a moderately small tropical cyclone with gales extending outward
from the center 90 nm to the north and about 60 nm in the southern
semicircle. However, JTWC's warnings described a smaller system with
gale radii ranging from 45-60 nm.
6. End of Track: Apr 06/1800 UTC, near 28.4S/167.1W, or about 600 nm
southwest of Rarotonga.
B. Synoptic History
-------------------
1. Origin: The initial depression (TD-14F) existed for several days to
the northwest of Fiji as a sheared system located in a highly-sheared
environment. TD-14F gradually drifted toward the southeast and upon
its approach to the northern Fijian island of Vanua Levu, this upper-
level wind shear relaxed sufficiently to allow the depression to
consolidate. The developing depression rounded the northeastern tip
of Vanua Levu, and at 04/0455 UTC, TD-014F was located to the south-
east of Vanua Levu, approximately 15 nm to the east of Taveuni Island,
and was upgraded to cyclone status at this time as convection and
gales wrapped tightly into the LLCC.
2. General Description of Track: Cyclone Cliff continued to track to the
south-southeast away from Vanua Levu at approximately 12 kts while
gradually intensifying due to good equatorial and polar outflow and
low to moderate upper-level shear. The peak intensity (estimated to
be 980 hPa; max 10-min avg wind 50 kts) was attained at 05/0600 UTC
approximately 125 nm west of Nuk'alofa, Tonga, and this intensity was
sustained for 24 hours due to improved polar outflow. Thereafter,
Cliff's increasing forward speed took the cyclone to the southeast and
into cooler seas and into a much higher wind shear environment. The
strongest thunderstorms gradually became displaced to the south of the
LLCC and Cliff began the process of extratropical transition. A mid-
level ridge to the northeast and an area of low pressure near New
Zealand continued to accelerate Cliff to the southeast at 20 kts, and
by 06/1200 UTC cyclone status was lost. The remnant depression
continued to the southeast into open waters, eventually merging with
a mid-latitude frontal boundary soon afterward about 600 nm southwest
of Rarotonga.
C. Meteorological Data
----------------------
No meteorological data are available.
D. Damage and Casualties
------------------------
Cyclone Cliff's main effect was to bring further flooding to the
northern parts of Fiji: the third time this season that flooding has
hit Fiji's north where more than 20 deaths were reported earlier in the
year.
An additional casualty occurred as a 30-year old woman was swept from
a flooded bridge at Nawaicoba near Nadi in the west, as TD-14F approached
the northern islands of Fiji's Eastern Division. Thirty students at a
primary school escaped serious injury when a landslide crashed into the
walls of their hostel near Udu Point at the eastern extremity of Vanua
Levu.
Flooded roads, minor damage to buildings and cut communications and
water supplies were reported in eastern parts of Vanua Levu and on
Taveuni Island. The people of Taveuni reported the loss of
"unaccountable acres" of crops as the developing cyclone passed close to
the island.
A resident of Tubou village in Lakeba confirmed that the roofs of
some houses were blown off and that most of the crops had been damaged
due to the strong winds. Extensive damage to crops and trees also
occurred elsewhere on the islands in the Lau Group.
There were no reports of any serious damage from southern Tonga.
(Report written by Simon Clarke)
*************************************************************************
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:
ftp://ftp.nhc.noaa.gov/pub/products/nhc/recon/
Information regarding how to interpret the coded reconnaissance
messages may be found at the following URL:
http://www.nhc.noaa.gov/reconlist.shtml
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:
http://www.nhc.noaa.gov/archive/2004/index.shtml
Links to tropical products archives for earlier years are available at
the following URL:
http://www.nhc.noaa.gov/pastall.shtml
JTWC warnings for past storms are archived on the NRL Monterrey website:
http://www.nrlmry.navy.mil/tc_pages/tc_home.html
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:
http://www.nrlmry.navy.mil/tc_pages/tc_home.html
http://cimss.ssec.wisc.edu/tropic/tropic.html
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:
http://www.ssd.noaa.gov/PS/TROP/trop-epac.html
(2) For the Atlantic, Gulf of Mexico and Caribbean Sea:
http://www.ssd.noaa.gov/PS/TROP/trop-atl.html
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):
http://australiasevereweather.com/cyclones/
http://www.typhoon2000.ph <http://www.typhoon2000.ph/>
http://mpittweather.com <http://mpittweather.com/>
ftp://ftp.aoml.noaa.gov/hrd/pub/landsea/padgett/
http://www.tropicalcyclone2005.com/
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.metoffice.gov.uk/weather/tropicalcyclone
TROPICAL CYCLONE REPORTS AVAILABLE
JTWC now has available on its website the Annual Tropical Cyclone
Report (ATCR) for 2005 (2004-2005 season for the Southern Hemisphere).
ATCRs for earlier years are available also.
The URL is: https://metocph.nmci.navy.mil/jtwc.php
Also, TPC/NHC has available on its webpage nice "technicolor"
tracking charts for the 2006 Atlantic and Eastern North Pacific
tropical cyclones; also, storm reports for all the 2006 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 <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: garyp@alaweb.com
Phone: 334-222-5327
Kevin Boyle (Northwest Pacific)
E-mail: newchapelobservatory@btinternet.com
Simon Clarke (Northeast Australia/Coral Sea, South Pacific)
E-mail: scla4255@bigpond.net.au
*************************************************************************
*************************************************************************
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