[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 150516
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT THU OCT 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
0345 UTC.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 64W S OF 14N MOVING W NEAR 15 KT. WAVE IS
AT THE LEADING EDGE OF AN AREA OF DEEP MOISTURE AS INDICATED IN
THE TOTAL PRECIPITABLE WATER IMAGERY AND REMAINS AT A LOW
AMPLITUDE. ISOLATED SHOWERS ARE S OF 14N TO INLAND OVER
VENEZUELA BETWEEN THE WINDWARD ISLANDS AND 67W.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 11N14W 7N27W 8N46W 10N52W 8N57W
10N62W. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ ALONG
33W/34W FROM 4N-10N AND A SECOND SURFACE TROUGH ALSO EMBEDDED
WITHIN THE ITCZ ALONG 52W FROM 8N-14N. SCATTERED MODERATE/STRONG
CONVECTION IS WITHIN 75 NM OF THE COAST OF W AFRICA BETWEEN
FREETOWN SIERRA LEONE AND BISSAU IN GUINEA-BISSAU. CLUSTERS OF
SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 6N-13N
BETWEEN 17W-29W AND FROM 7N-11N BETWEEN 52W-59W.

...DISCUSSION...

GULF OF MEXICO...
BROAD UPPER RIDGE CONTINUES TO DOMINATE THE GULF ANCHORED OVER
N/CENTRAL MEXICO WITH AN AXIS EXTENDING E ACROSS EXTREME S
FLORIDA INTO THE W ATLC. MOSTLY DRY STABLE AIR DOMINATES THE
AREA WITH SOME LINGERING ISOLATED SHOWERS OVER THE NE GULF N OF
27N E OF 86W AS A RESULT OF AN UPPER LEVEL SHORTWAVE TROUGH
MOVING ACROSS NE FLORIDA INTO THE W ATLC. AFTERNOON
THUNDERSTORMS THAT DEVELOPED INLAND OVER THE YUCATAN PENINSULA
ARE MOVING INTO THE E BAY OF CAMPECHE WITHIN 60 NM S OF 21N E OF
92W. SIMILAR ACTIVITY DEVELOPED OVER W CUBA MOVING INTO THE SE
GULF AND THE YUCATAN CHANNEL WITHIN 45 NM OF LINE FROM 23N83W TO
22N87W. THE REMAINDER OF THE GULF IS EXPERIENCING FAIR WEATHER
WITH REMARKABLY CLEAR SKIES AGAIN TONIGHT. THE NEXT FRONT TO
ENTER THE GULF WATERS WILL BE ON FRI.

CARIBBEAN SEA...
THE BROAD UPPER RIDGE THAT COVERS MOST OF THE ATLC AND GULF OF
MEXICO IS GIVING THE CARIBBEAN UPPER EASTERLY WINDS N OF A SHEAR
AXIS THAT ENTERS THE CARIBBEAN OVER THE LESSER ANTILLES BETWEEN
MARTINIQUE AND DOMINICA ALONG 14N73W TO PANAMA NEAR 9N79W
PRODUCING PATCHES OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS
OVER HAITI FROM 17N-19N BETWEEN 71W-75W AND WITHIN 90 NM ALONG
THE S COAST OF CUBA FROM 77W-80W AND IN THE SW CARIBBEAN S OF
12N E OF 82W TO INLAND OVER COLOMBIA AND PANAMA. ISOLATED
SHOWERS ARE OVER THE NE CARIBBEAN N OF 17N E OF 71W FROM THE
LEEWARD ISLANDS TO THE DOMINICAN REPUBLIC. THE REMAINDER OF THE
CARIBBEAN IS UNDER A VERY DRY AND STABLE AIRMASS GIVING THAT
AREA CLEAR SKIES AGAIN TONIGHT.

ATLANTIC OCEAN...
AN UPPER LEVEL SHORTWAVE TROUGH IS MOVING ACROSS NE FLORIDA INTO
THE W ATLC N OF 29N W OF 78W. A MID/UPPER LEVEL TROUGH IS
FURTHER TO THE E AND N OF 30N FROM 50W-55W SUPPORTING A COLD
FRONT THAT ENTERS THE REGION NEAR 32N54W EXTENDING ALONG 27N67W
27N72W THEN NW TO A 1009 MB LOW OFF THE COAST OF SOUTH CAROLINA
NEAR 32N79W. A DISSIPATING FRONTAL BOUNDARY IS JUST TO THE N
EXTENDING THROUGH 32N57W 28N67W TO 29N74W. SCATTERED SHOWERS/
ISOLATED THUNDERSTORMS ARE WITHIN 60/75 NM OF LINE FROM 27N61W
TO BEYOND 32N50W WITH CLUSTERS OF SIMILAR ACTIVITY N OF 28N W OF
70W. A WEAK 1015 MB HIGH IS OVER THE BAHAMA ISLANDS NEAR 26N76W.
A BROAD UPPER RIDGE CONTINUES TO DOMINATE THE ATLC W OF 35W
EXTENDING AN AXIS FROM ACROSS THE GULF OVER EXTREME S FLORIDA
ALONG 25N68W TO NEAR 22N35W AND IS PROVIDING DIFFLUENCE ALOFT TO
ENHANCING THE ACTIVITY ASSOCIATED WITH THE FRONT ABOVE. A SHARP
UPPER TROUGH DIGS S INTO THE E ATLC NEAR 32N27W S TO 16N30W THEN
EXTENDS W AS A SHEAR AXIS ALONG 20N47W OVER THE LESSER ANTILLES
BETWEEN MARTINIQUE AND DOMINICA INTO THE S CARIBBEAN. THIS UPPER
TROUGH IS SUPPORTING A WEAKENING SURFACE TROUGH EXTENDING ALONG
30N31W 25N31W THEN W TO 24N40W. SCATTERED SHOWERS AND POSSIBLE
ISOLATED THUNDERSTORMS ARE FROM 25N-29N BETWEEN 21W AND THE
ABOVE SURFACE TROUGH.

$$
WALLACE



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