[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 150549
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SAT AUG 15 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
0415 UTC.

...SPECIAL FEATURES...
TROPICAL DEPRESSION TWO HAS REGENERATED CENTERED NEAR 14.6N
45.8W AT 15/0430 UTC OR ABOUT 1075 MILES EAST OF THE LEEWARD
ISLANDS MOVING W 13 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS
1005 MB. MAXIMUM SUSTAINED WIND SPEED IS 30 KT WITH GUST TO 40
KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS
MIATCMAT2/WTNT22 KNHC FOR MORE DETAILS. SCATTERED MODERATE/
ISOLATED STRONG CONVECTION COVERS THE AREA FROM 13N-16N BETWEEN
45W-48W.

TROPICAL WAVE EXTENDS FROM 19N32W TO 6N29W WITH A 1011 MB LOW
ALONG THE WAVE NEAR 13N MOVING W 10-15 KT. THIS SYSTEM IS
GRADUALLY BECOMING BETTER ORGANIZED AND A TROPICAL DEPRESSION
COULD FORM LATER TODAY. SCATTERED/NUMEROUS STRONG CONVECTION IS
TO THE W OF THE LOW FROM 11N-13N BETWEEN 31W-32W. SCATTERED
MODERATE TO ISOLATED STRONG CONVECTION COVERS THE REMAINDER OF
THE AREA W OF THE WAVE FROM 10N-14N BETWEEN 31W-35W.

...TROPICAL WAVES...
TROPICAL WAVE IS ALONG 79W/80W S OF 20N MOVING W 15-20 KT. THE
NORTH PORTION OF THIS WAVE IS NOW A SURFACE TROUGH MOVING ACROSS
THE BAHAMAS AT 0300 UTC. WAVE COINCIDES WITH A HIGH AMPLITUDE
DEEP MOISTURE MAXIMUM OBSERVED IN TOTAL PRECIPITABLE WATER
IMAGERY AND IS WELL DEFINED IN THE LOW LEVELS AS OBSERVED ON
INFRARED SATELLITE IMAGERY. THIS COUPLED WITH THE UPPER LOW THAT
IS OVER THE W CARIBBEAN IS PRODUCING A BROAD AREA OF SCATTERED/
NUMEROUS SHOWERS/THUNDERSTORMS OVER THE AREA FROM 16N-20N
BETWEEN 75W-81W AND N OF 20N OVER CUBA BETWEEN 77W-84W.
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE OVER THE SW
CARIBBEAN S OF 14N BETWEEN 75W-83W.

TROPICAL WAVE IS ALONG 91W/92W S OF 20N MOVING W NEAR 20 KT.
THIS WAVE IS MOSTLY IN THE E PACIFIC REGION AND IS NOT PRODUCING
ANY SHOWERS/THUNDERSTORMS IN THE GULF OF MEXICO.

...ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 14N16W 12N27W 15N43W THEN ALONG
12N47W 11N61W ACROSS THE NORTH PORTION OF SOUTH AMERICA THEN
ACROSS PANAMA INTO THE E PACIFIC REGION. SCATTERED MODERATE/
ISOLATED STRONG CONVECTION IS INLAND AND WITHIN 75 NM ALONG THE
COAST OF W AFRICA FROM 10N-13N. SIMILAR CONVECTION IS WITHIN 75
NM S OF THE ITCZ FROM 55W-57W. CLUSTERS OF SCATTERED MODERATE
CONVECTION ARE FROM 8N-10N BETWEEN 37W-46W.

...DISCUSSION...

GULF OF MEXICO...
AN UPPER TROUGH DIGS S OVER THE N GULF WHILE THE UPPER LOW IN
THE W CARIBBEAN IS COMBINING TO DRAW UPPER LEVEL MOISTURE OVER
THE E GULF BUT IS CURRENTLY ONLY PRODUCING ISOLATED SHOWERS
ACROSS THE AREA. UPPER RIDGE ANCHORED OVER S/CENTRAL MEXICO
COVERS THE SW GULF PROVIDING DRIER AIR LIMITING SHOWERS IN THE
BAY OF CAMPECHE. AT 0300 UTC A WEAK SURFACE TROUGH EXTENDS FROM
NEAR FORT MYERS FLORIDA SSW TO 25N84W. ALTHOUGH THE GULF IS
CURRENTLY SOMEWHAT TRANQUIL CONDITIONS WILL WORSEN LATER THIS
MORNING ESPECIALLY FOR S FLORIDA AND THE STRAITS OF FLORIDA AS
THE SHOWERS/THUNDERSTORMS OVER THE BAHAMAS WILL MOVE INTO THE
AREA.

CARIBBEAN SEA...
AN UPPER LOW IS OVER THE W CARIBBEAN CENTERED JUST SW OF THE
CAYMAN ISLANDS COVERING THE AREA W OF 75W ENHANCING THE ACTIVITY
ASSOCIATED WITH THE TROPICAL WAVE ALONG 79W/80W. AN UPPER RIDGE
COVERS THE REMAINDER OF THE CARIBBEAN...THUS PROVIDING THE AREA
E OF 75W WITH DRY UPPER AIR. FRESH TO STRONG EASTERLY TRADE
WINDS CONTINUES ACROSS THE CARIBBEAN USHERING IN ISOLATED
SHOWERS MAINLY OVER THE E CARIBBEAN E OF 67W.

ATLANTIC OCEAN...
THE UPPER LOW IN THE W CARIBBEAN EXTENDS AN UPPER TROUGH OVER
THE FAR SW ATLC S OF 26N W OF 75W AND UPPER HIGH IS NNE OF THE
BAHAMAS NEAR 27N76W. AT 0300 UTC A SURFACE TROUGH EXTENDS FROM
CUBA NEAR 22N79W TO OVER THE BAHAMAS NEAR 26N78W AND COUPLED
WITH UPPER DIFFLUENCE IS GENERATING SCATTERED/NUMEROUS SHOWERS/
THUNDERSTORMS OVER THE AREA FROM 26N TO OVER CUBA BETWEEN 76W TO
81W IN THE STRAITS OF FLORIDA. THIS ACTIVITY WILL BE MOVING INTO
THE SE GULF LATER THIS MORNING. AN UPPER LOW IS TO THE W OF THE
UPPER HIGH CENTERED NEAR 25N63W AGAIN PROVIDING UPPER DIFFLUENCE
TO GENERATE ISOLATED SHOWERS/THUNDERSTORMS WITHIN 75 NM OF LINE
FROM 26N69W TO 32N75W. AT 0000 UTC A SURFACE TROUGH IS IN THE
CENTRAL ATLC EXTENDING FROM 32N52W ALONG 29N56W TO 25N57W. THIS
TROUGH IS EMBEDDED WITH A BROAD SURFACE RIDGE THAT DOMINATES THE
ATLC ANCHORED BY A 1023 MB HIGH JUST N OF BERMUDA AND A 1025 MB
HIGH SW OF THE AZORES.

$$
WALLACE






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