[Tropical] Tropical Weather Discussion

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AXNT20 KNHC 272358
TWDAT

TROPICAL WEATHER DISCUSSION...
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 PM EDT WED AUG 27 2008

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...
TROPICAL STORM GUSTAV IS CENTERED NEAR 19.0N 75.0W AT 28/0000
UTC OR ABOUT 56 NM SOUTH OF GUANTANAMO CUBA MOVING WEST AT 6 KT.
ESTIMATED MINIMUM CENTRAL PRESSURE IS 999 MB. MAXIMUM SUSTAINED
WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. PLEASE SEE THE LATEST
NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22
KNHC AND/OR THE PUBLIC ADVISORY MIATCPAT2/WTNT32 KNHC FOR MORE
DETAILS. A WNW TO W TRACK IS FORECAST DURING THE NEXT DAY OR TWO
WITH A GRADUAL INCREASE IN FORWARD SPEED. ON THE FORECAST TRACK
GUSTAV SHOULD PASS BETWEEN JAMAICA AND THE SE COAST OF CUBA ON
THU. GRADUAL STRENGTHENING IS FORECAST AND GUSTAV COULD REGAIN
HURRICANE STRENGTH ON THU AS IT MOVES FARTHER OUT OVER THE
WARMER NRN CARIBBEAN SEA WATERS. SCATTERED MODERATE/STRONG
CONVECTION IS WITHIN 90 NM OF THE CENTER IN THE SOUTHERN
SEMICIRCLE. SIMILAR CONVECTION IS ASSOCIATED WITH AN OUTER BAND
SOUTH OF JAMAICA FROM 15N-18N BETWEEN 75W-79W. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS FROM 15N-20N BETWEEN
71W-75W. GUSTAV IS EXPECTED TO PRODUCE TOTAL RAINFALL
ACCUMULATIONS OF 6 TO 12 INCHES OVER HAITI... EASTERN CUBA...
JAMAICA...AND THE CAYMAN ISLANDS...WITH ISOLATED MAXIMUM AMOUNTS
OF UP TO 25 INCHES POSSIBLE. THESE RAINS WILL LIKELY PRODUCE
LIFE-THREATENING FLASH FLOODS AND MUD SLIDES.

A 1009 MB SURFACE LOW NEAR 19N57W IS SLOWLY DRIFTING WNW AND
REMAINS FAVORABLE FOR DEVELOPMENT OVER THE NEXT DAY OR TWO. AN
UPPER LEVEL RIDGE EXTENDS FROM THE ERN CARIBBEAN OUT INTO THE
CENTRAL ATLC AND IS PROVIDING DIFFLUENCE ALOFT TO GENERATE
SCATTERED MODERATE TO STRONG CONVECTION FROM 18N-21N BETWEEN
53W-59W.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 34W S OF 21N MOVING W 15-20 KT. A 1009 MB
LOW IS ANALYZED ALONG THE WAVE AXIS NEAR 16N WITH A BROAD AREA
OF DEEP LAYERED MOISTURE EVIDENT ON SATELLITE IMAGERY. SCATTERED
MODERATE/ISOLATED STRONG CONVECTION IS FROM 17N-19N BETWEEN
31W-33W WITH SCATTERED SHOWERS FROM 16N-21N BETWEEN 31W-39W.

TROPICAL WAVE IS ALONG 48W S OF 17N MOVING W NEAR 20 KT. THIS
WAVE EXHIBITS A LOW AMPLITUDE AND IS EMBEDDED WITHIN SOME RATHER
DRY AIR. NO ASSOCIATED SHOWERS/DEEP CONVECTION.

TROPICAL WAVE IN THE SW CARIBBEAN IS ALONG 81W S OF 13N MOVING W
NEAR 20 KT. ALTHOUGH THIS WAVE REMAINS EMBEDDED WITHIN DEEP
LAYERED MOISTURE AND THE ITCZ...SCATTERED MODERATE TO STRONG
CONVECTION IS ACROSS INLAND WRN PANAMA AND COSTA RICA.

TROPICAL WAVE IN THE GULF OF MEXICO IS ALONG 97W S OF 20N
MOVING W 15-20 KT. WAVE IS MOSTLY OVER S MEXICO AND THE E
PACIFIC REGION PRODUCING SCATTERED MODERATE TO STRONG CONVECTION
FROM 14N-18N BETWEEN 94W-97W.

...THE ITCZ...
THE ITCZ AXIS IS ANALYZED ALONG 17N16W 16N25W 12N32W 10N36W
8N46W 7N50W 7N59W. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE
FROM 8N-14N BETWEEN 16W-21W. SCATTERED MODERATE CONVECTION IS
WITHIN 90 NM OF THE AXIS BETWEEN 26W-33W.

...DISCUSSION...

GULF OF MEXICO...
A MIDDLE TO UPPER TROUGH IS ACROSS THE CENTRAL AND WRN GULF OF
MEXICO WITH AN UPPER HIGH REMAINING ANCHORED IN THE FLORIDA
STRAITS NEAR 23N81W COVERING THE ERN GULF AND THE FLORIDA
PENINSULA INTO THE W ATLC. UPPER DIFFLUENCE EAST OF THIS TROUGH
IS GENERATING MULTILAYERED CLOUDINESS AND A FEW ISOLATED SHOWERS
WITHIN 90 NM OF A LINE FROM APALACHICOLA BAY FLORIDA TO NEAR
25N92W. A CLUSTER OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS
ARE ALSO NOTED ACROSS SERN LOUISIANA DUE TO THE UPPER TROUGH.
SCATTERED SHOWERS/THUNDERSTORMS ARE ACROSS THE SRN FLORIDA
PENINSULA IN ASSOCIATION WITH THE UPPER DIFFLUENT PATTERN IN
PLACE OVER THE REGION. WITH THE TROPICAL WAVE AND AN UPPER RIDGE
ACROSS SRN MEXICO...SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE
ACROSS THE YUCATAN PENINSULA AND SRN MEXICO. AT THE SURFACE...A
WEAK 1015 MB HIGH PRESSURE IS CENTERED NEAR 27N86W AND IS
KEEPING THE REMAINDER OF THE SE GULF WITH TRANQUIL WEATHER.

CARIBBEAN SEA...
THE MAIN CONCERN FOR THE CARIBBEAN IS T.S. GUSTAV BETWEEN HAITI
AND CUBA...SEE SPECIAL FEATURES ABOVE. AN UPPER HIGH CENTERED
OVER THE FLORIDA STRAITS COVERS THE NW CARIBBEAN AND IS
PROVIDING UPPER LEVEL DIFFLUENCE TO PRODUCE CLUSTERS OF
SCATTERED SHOWERS/THUNDERSTORMS ALONG THE SRN CUBA COASTLINE
WITHIN 90 NM. THIS UPPER RIDGE IS KEEPING THE REMAINDER OF THE
NW CARIBBEAN RELATIVELY CLEAR THIS EVENING. CLUSTERS OF
SCATTERED SHOWERS AND THUNDERSTORMS ASSOCIATED WITH T.S. GUSTAV
ARE ACROSS THE CENTRAL CARIBBEAN SEA FROM 14N-20N BETWEEN
70W-79W. AN UPPER LEVEL RIDGE IS ACROSS THE ERN CARIBBEAN NEAR
16N67W AND IS PROVIDING UPPER DIFFLUENCE TO GENERATE SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS ACROSS THE MONA PASSAGE AND
PUERTO RICO EXTENDING SOUTHEASTWARD TO ACROSS THE LESSER
ANTILLES N OF SAINT LUCIA AND EAST OF 64W.

ATLANTIC OCEAN...
AN UPPER RIDGE ANCHORED IN THE FLORIDA STRAITS NEAR 23N81W
COVERS THE W ATLC W OF 69W. A BROAD UPPER TROUGH ENCOMPASSES THE
REMAINDER OF THE W ATLC FROM 58W-69W WITH AN EMBEDDED UPPER LOW
N OF PUERTO RICO NEAR 22N65W GENERATING SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS FROM 21N TO OVER THE ERN GREATER ANTILLES
BETWEEN 64W-70W INCLUDING PUERTO RICO AND THE VIRGIN ISLANDS. A
SURFACE TROUGH IS ANALYZED ALONG 27N63W TO 21N66W GENERATING
ISOLATED SHOWERS FROM 21N-25N BETWEEN 63W-68W. AN UPPER RIDGE
EXTENDS FROM THE ERN CARIBBEAN TO NEAR 19N50W WITH A 1009 MB
SURFACE LOW NEAR 19N57W AND COUPLED WITH THE UPPER LEVEL
DIFFLUENCE IS GENERATING SCATTERED MODERATE TO STRONG CONVECTION
FROM 18N-21N BETWEEN 53W-59W. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION ALSO EXTENDS S-SE FROM THE LOW FROM 14N-20N BETWEEN
53W-56W. A SECOND BUT BENIGN UPPER LOW COVERS THE E/CENTRAL ATLC
CENTERED NEAR 31N43W EXTENDING S TO 22N. AN UPPER RIDGE COVERS
THE REMAINDER OF THE ERN ATLC E OF 38W ANCHORED ON AN UPPER HIGH
CENTERED OVER WESTERN SAHARA. BROAD SURFACE RIDGE REMAINS OVER
THE ATLC N OF 25N E OF 52W ANCHORED BY A 1030 MB HIGH N OF THE
AZORES. A WEAK SURFACE RIDGE EXTENDS SW FROM BERMUDA NEAR 30N70W
TO OVER THE NW BAHAMAS.

$$
HUFFMAN




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