[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 102337
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT THU SEP 10 2009

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL
AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTIONS
OF SOUTH AMERICA...AND ATLANTIC OCEAN TO THE AFRICAN COAST
FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED
ON SATELLITE IMAGERY...METEOROLOGICAL ANALYSIS...WEATHER
OBSERVATIONS...AND RADAR.

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2315 UTC.

...SPECIAL FEATURES...

HURRICANE FRED IS CENTERED NEAR 17.3N 35.1W AT 10/2100 UTC OR
ABOUT 640 NM W OF THE CAPE VERDE ISLANDS MOVING N AT 4 KT.
ESTIMATED CENTRAL PRESSURE IS 975 MB. MAXIMUM SUSTAINED WIND
SPEED IS 80 KT WITH GUSTS TO 100 KT. SEE LATEST NHC FORECAST/
ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC FOR MORE
DETAILS. CLOUD PATTERN IS BECOMING ELONGATED DUE TO INCREASING
SWLY SHEAR. SCATTERED MODERATE/STRONG CONVECTION IS FROM 16N-19N
BETWEEN 34W-36W. SCATTERED MODERATE CONVECTION COVERS THE
REMAINDER OF THE AREA FROM 16N-21N BETWEEN 32W-37W.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 74W/75W S OF 19N MOVING W 10-15 KT. WAVE
IS BEGINNING TO LAG THE DEEP LAYER MOISTURE AS INDICATED BY
TOTAL PRECIPITABLE WATER IMAGERY. WAVE IS AT THE BASE OF AN
UPPER TROUGH EXTENDING FROM AN UPPER LOW N OF PUERTO RICO AND
WITHIN AN AREA OF LOW LEVEL DRY AIR. THUS NO ASSOCIATED
SHOWERS/CONVECTION.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 9N12W 8N22W 13N31W 11N41W 12N48W
10N56W 10N62W. SCATTERED STRONG CONVECTION IS WITHIN 60 NM OF
LINE FROM 13N18W TO 15N17W INCLUDING DAKAR IN SENEGAL W AFRICA.
SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 12N-15N
BETWEEN 39W-41W. CLUSTERS OF SIMILAR CONVECTION ARE FROM 8N-11N
BETWEEN 37W-57W. SMALL CLUSTERS OF SCATTERED MODERATE CONVECTION
ARE FROM 5N-13N BETWEEN 18W-23W.

...DISCUSSION...

GULF OF MEXICO...
AS OF 2100 UTC...A 1010 MB LOW SURFACE LOW HAS DEVELOPED INLAND
JUST W OF MATAMOROS MEXICO WITH A SURFACE TROUGH EXTENDING FROM
NEAR MATAGORDA BAY TEXAS THROUGH THE SURFACE LOW TO NEAR TAMPICO
MEXICO. A SECOND SURFACE IS OVER THE SE GULF EXTENDING FROM
23N87W NE ALONG 26N83W ACROSS THE FLORIDA PENINSULA NEAR NAPLES
INTO THE W ATLC NEAR FORT LAUDERDALE. AT THE UPPER LEVELS...AN
UPPER TROUGH IS OVER TEXAS AND THE N PORTION OF MEXICO INDUCING
A SHARP UPPER RIDGE ALONG THE MEXICO/TEXAS COAST WITH A SECOND
UPPER TROUGH OVER THE CAROLINAS S TO OVER NE FLORIDA. THIS IS
CREATING A VERY DIFFLUENT ALOFT ENVIRONMENT ACROSS THE ENTIRE
GULF AND COUPLED WITH THE BROAD AREA OF DEEP LAYERED MOISTURE AS
INDICATED BY THE TOTAL PRECIPITABLE WATER IMAGERY IS ENHANCING
SCATTERED/NUMEROUS SHOWERS WITH SCATTERED THUNDERSTORMS OVER
MOST OF THE AREA. THE ONLY EXCEPTION IS IN THE SW GULF AND THE
BAY OF CAMPECHE S OF 22N WHERE ONLY HIGH DEBRIS CLOUDS ARE
FOUND.

CARIBBEAN SEA...
AN UPPER TROUGH COVERS THE W CARIBBEAN EXTENDING FROM W PANAMA
TO NEAR THE CAYMAN ISLANDS AS WELL AS DEEP LAYERED MOISTURE AS
INDICATED BY THE TOTAL PERCEPTIBLE WATER IMAGERY AND WITH
DIFFLUENCE ALOFT OVER THE SE GULF OF MEXICO ARE GENERATING
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND OVER CUBA AND IN
THE CARIBBEAN WATERS N OF 21N. AN AREA OF ISOLATED/SCATTERED
SHOWERS ARE OVER THE SW CARIBBEAN S OF 15N BETWEEN 77W-82W. A
SECOND UPPER TROUGH COVERS THE NE CARIBBEAN EXTENDING FROM THE
W/CENTRAL ATLC ACROSS HISPANIOLA AND PUERTO RICO TO 15N BETWEEN
65W-75W. THE ITCZ EXTENDS ACROSS THE N PORTION OF SOUTH AMERICA
AND PANAMA INTO THE E PACIFIC REGION GENERATING SCATTERED
SHOWERS/THUNDERSTORMS INLAND AND WITHIN 45 NM ALONG THE COAST OF
PANAMA E OF 80W. OTHERWISE THE REMAINDER OF THE CARIBBEAN IS
FAIRLY TRANQUIL THIS EVENING.

ATLANTIC OCEAN...
AS OF 2100 UTC...A SURFACE TROUGH EXTENDS THROUGH 32N72W SW
ALONG 27N77W ACROSS THE FLORIDA PENINSULA INTO THE GULF OF
MEXICO NEAR FORT LAUDERDALE TO NAPLES. AN UPPER TROUGH
SUPPORTING THE SURFACE TROUGH COVERS THE CAROLINAS S TO OVER NE
FLORIDA AND INTO THE W ATLC N OF 27N W OF 75W. A NARROW UPPER
RIDGE EXTENDS FROM THE N BAHAMA ISLANDS NE TO NEAR BERMUDA
PROVIDING DIFFLUENCE ALOFT TO GENERATE A BROAD AREA OF SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS SE OF THE SURFACE TROUGH AND W OF
A LINE FROM 30N67W 25N67W TO E CUBA NEAR 20N74W. A WEAK 1015 MB
SURFACE LOW IS N OF PUERTO RICO NEAR 22N66W. THE LOW IS
SUPPORTED BY AN UPPER LEVEL TROUGH THAT COVERS THE W ATLC S OF
28N INTO THE NE CARIBBEAN BETWEEN 60W-70W AND CENTERED NEAR
25N66W. A WEAK 1020 MB SURFACE HIGH IS NNE OF THE SURFACE LOW
CENTERED NEAR 29N63W. FARTHER E...AN UPPER TROUGH ENTERS THE
CENTRAL ATLC NEAR 32N35W TO A LARGE RATHER DRY UPPER LOW NEAR
21N48W SUPPORTING A SURFACE TROUGH EXTENDING FROM 31N43W TO
25N55W WITH ISOLATED SHOWERS WITHIN 120 NM EITHER SIDE OF THE
SURFACE TROUGH. THIS UPPER LOW IS ALSO SUPPORTING A SECOND
SURFACE TROUGH THAT EXTENDS FROM 25N46W S TO 14N48W WITH
POSSIBLE ISOLATED SHOWERS WITHIN 90 NM E OF THE SURFACE TROUGH N
OF 20N. A SURFACE RIDGE IS OVER THE E ATLC EXTENDING N OF 25N
FROM 20W-40W. A WEAK 1015 MB LOW IS N OF THE CANARY ISLANDS NEAR
31N16W SUPPORTED BY AN UPPER TROUGH THAT EXTENDS FROM INLAND
OVER MOROCCO SW TO OVER THE CANARY ISLANDS.

$$
WALLACE







This weather bulletin was brought to you by:
www.nashvilleweather.net