[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 160542
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI OCT 16 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 69W S OF 15N MOVING W NEAR 15 KT. WAVE IS
EMBEDDED WITHIN AN AREA OF DEEP MOISTURE AS INDICATED IN THE
TOTAL PRECIPITABLE WATER IMAGERY REMAINING AT A LOW AMPLITUDE.
ISOLATED SHOWERS ARE S OF 13N TO INLAND OVER VENEZUELA BETWEEN
67W-71W INCLUDING THE ABC ISLANDS.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 10N11W 6N25W 8N40W 7N48W 10N57W.
A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ ALONG 39W FROM
6N-11N WITH A SECOND SURFACE TROUGH ALSO EMBEDDED WITHIN THE
ITCZ ALONG 57W FROM 8N-14N. SCATTERED MODERATE/ISOLATED STRONG
CONVECTION IS WITHIN 75 NM OF THE ITCZ FROM 40W-44W. CLUSTERS OF
SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 4N-13N E
OF 35W TO JUST INLAND OVER THE COAST OF W AFRICA. SCATTERED
MODERATE CONVECTION IS FROM 12N-15N BETWEEN 58W-61W INCLUDING
THE WINDWARD ISLANDS.

...DISCUSSION...

GULF OF MEXICO...
THE PATTERN OF THE PAST FEW DAYS HAS FINALLY BROKEN DOWN AS THE
BROAD UPPER RIDGE THAT HAD DOMINATED THE GULF AND MOST OF THE
ATLC HAS RETREATED TO OVER MEXICO AND THE FAR W GULF. A BROAD
UPPER TROUGH IS OVER THE E HALF OF THE US COVERING THE N GULF TO
25N WITH THE ACCOMPANYING FRONTAL BOUNDARY INLAND OVER THE GULF
COAST STATES GENERATING SCATTERED TO HEAVY SHOWERS WITH
SCATTERED TO NUMEROUS THUNDERSTORMS FROM OVER S GEORGIA TO
LOUISIANA INCLUDING THE W FLORIDA PANHANDLE WITH ISOLATED
SHOWERS OVER THE N GULF WATERS N OF 26N E OF 92W. EASTERLY UPPER
FLOW OVER THE CARIBBEAN IS GENERATING SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS OVER W CUBA MOVING OVER THE SE GULF WITHIN 60 NM
OF THE COAST OF CUBA W OF 82W. THE REMAINDER OF THE GULF IS
DOMINATED BY DRY STABLE AIR GIVING THE AREA CLEAR SKIES TONIGHT.
THE COLD FRONT IS EXPECTED TO ENTER THE GULF OFF THE COAST OF
TEXAS BY LATER THIS MORNING.

CARIBBEAN SEA...
AN UPPER RIDGE IS ANCHORED OVER THE SW CARIBBEAN NEAR 13N81W
WITH AN AXIS EXTENDING NE ALONG 16N70W TO OVER THE LEEWARD
ISLANDS NEAR 17N62W. THIS IS CONTINUING TO GIVE THE N CARIBBEAN
EASTERLY UPPER FLOW GENERATING SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS OVER HAITI AND THE IMMEDIATE COASTAL WATERS AND W
GULF WITH THE ACTIVITY MOVING INTO THE SE GULF OF MEXICO. THIS
UPPER RIDGE IS DRAWING UPPER LEVEL TROPICAL MOISTURE OVER THE SE
CARIBBEAN AND COUPLED WITH A SURFACE TROUGH IN THE W TROPICAL
ATLC IS GIVING THE AREA S OF 16N E OF THE TROPICAL WAVE ACROSS
THE WINDWARD ISLANDS SCATTERED SHOWERS AND POSSIBLE ISOLATED
THUNDERSTORMS. A SMALL AREA OF SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ARE IN THE SW CARIBBEAN S OF 12N TO THE COAST OF
PANAMA BETWEEN 79W-81W. THE REMAINDER OF THE CARIBBEAN IS UNDER
A VERY DRY AND STABLE AIRMASS GIVING THE AREA CLEAR SKIES AGAIN
TONIGHT.

ATLANTIC OCEAN...
BROAD UPPER TROUGH OVER THE E US AND N GULF OF MEXICO COVERS THE
W ATLC N OF 26N W OF 62W WITH THE ASSOCIATED FRONTAL SYSTEM N OF
THE REGION BUT GENERATING SCATTERED SHOWERS/THUNDERSTORMS N OF
26N FROM 77W-80W. A BROAD UPPER RIDGE REMAINS OVER THE W ATLC
ANCHORED NEAR 25N58W EXTENDING AN AXIS NE TO BEYOND 32N40W. A
BROAD UPPER LEVEL TROUGH IS N OF 30N FROM 40W-50W SUPPORTING A
COLD FRONT THAT DRAPES INTO THE REGION NEAR 32N44W EXTENDING
ALONG 28N52W WITH THE FRONTAL BOUNDARY CONTINUING ALONG 27N59W
THE NW  TO BEYOND 32N66W. ISOLATED SHOWERS ARE WITHIN 120 NM OF
FRONT N OF 30N. A WEAK 1018 MB HIGH IS LOCATED NEAR 25N54W AND A
EQUALLY WEAK 1017 MB HIGH IS LOCATED NEAR 27N44W. BROAD COMPLEX
UPPER LEVEL TROUGH COVERS THE E ATLC N OF 16N E OF 40W
SUPPORTING A COMPLEX TROUGH SYSTEM WITH A 1012 MB LOW CENTERED
NEAR 29N28W. SCATTERED SHOWERS WITH POSSIBLE ISOLATED
THUNDERSTORMS ARE N OF 23N FROM 24W-30W.

$$
WALLACE





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