[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 131143
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
805 AM EDT TUE OCT 13 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
1015 UTC.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 17N44W TO 8N51W MOVING W 10-15 KT.
WAVE REMAINS TILTED WITH SMALL CYCLONIC CIRCULATIONS SPINNING
OFF TO THE NE CAUGHT UP IN AN UPPER TROUGH. WAVE IS EMBEDDED
WITHIN A LOW AMPLITUDE AREA OF DEEP MOISTURE IN THE TOTAL
PRECIPITABLE WATER IMAGERY WITH SATELLITE DERIVED WINDS
INDICATING CYCLONIC CURVATURE EXTENDING AS FAR N AS 18N43W.
THERE ARE NO ASSOCIATED SHOWERS OR DEEP CONVECTION.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 12N15W 6N31W 10N47W 9N62W. A
SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ FROM 13N55W TO 8N56W
WITH CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION
FROM 10N-15N BETWEEN 51W-57W. CLUSTERS OF SCATTERED MODERATE TO
ISOLATED STRONG CONVECTION ARE FROM 4N-10N BETWEEN 12W-30W AND
FROM 7N-10N BETWEEN 43W-61W.

...DISCUSSION...

GULF OF MEXICO...
THE QUASI-STATIONARY FRONT REMAINS ACROSS THE N GULF CONTINUING
TO MEANDER BUT IS NOW MOSTLY INLAND FROM THE FLORIDA PANHANDLE
TO TEXAS GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N
OF A LINE FROM 27N91W TO 23N97W TO INLAND OVER LOUISIANA AND
TEXAS. BROAD UPPER RIDGE CONTINUES TO DOMINATE THE ENTIRE BASIN
WITH THE AXIS EXTENDING FROM THE TEXAS/MEXICO BORDER E ACROSS
FLORIDA N OF LAKE OKEECHOBEE INTO THE ATLC. THE DIFFLUENCE ALOFT
IS ENHANCING THE ACTIVITY ASSOCIATED WITH THE FRONT OVER THE N
GULF. THE REMAINDER OF THE GULF IS EXPERIENCING FAIR WEATHER
WITH CLEAR SKIES AGAIN THIS MORNING. A SURFACE RIDGE CONTINUES
TO NUDGE WESTWARD ACROSS THE GULF.

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 S CARIBBEAN OVER THE WINDWARD ISLANDS NEAR
SAINT LUCIA ALONG 12N78W TO NICARAGUA NEAR 14N84W PRODUCING
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 18N-22N BETWEEN
79W-84W INCLUDING THE CAYMAN ISLANDS AND WITHIN 75 NM ALONG THE
S COAST OF THE DOMINICAN REPUBLIC WITH A SWATH OF ISOLATED
SHOWERS WITHIN 120 NM OF A LINE FROM ACROSS THE LEEWARD ISLANDS
NEAR 17N62W ALONG 17N78W INTO GULF OF HONDURAS TO OVER CENTRAL
AMERICA NEAR 16N88W. THE ITCZ EXTENDS ACROSS THE EXTREME SW
WATERS OF THE CARIBBEAN FROM COLOMBIA TO THE PANAMA/COSTA RICA
BORDER AND INTO THE E PACIFIC REGION GENERATING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS S OF 12N TO INLAND OVER PANAMA
BETWEEN 76W-82W. VERY DRY AIR AND SUBSIDENCE IS OVER THE
REMAINDER OF THE CARIBBEAN MAINLY FROM 11N-15N GIVING THAT AREA
CLEAR SKIES AGAIN THIS MORNING.

ATLANTIC OCEAN...
A QUASI-STATIONARY FRONT THAT REMAINS ALONG THE N GULF COAST
STATES ENTERS THE REGION NEAR 32N79W CONTINUING ACROSS SE
GEORGIA JUST N OF JACKSONVILLE FLORIDA. BROAD UPPER RIDGE
DOMINATES THE ATLC W OF 45W WITH THE AXIS EXTENDING FROM ACROSS
THE GULF AND THE FLORIDA PENINSULA N OF LAKE OKEECHOBEE TO NEAR
27N44W. A WEAK SURFACE RIDGE COVERS THE W ATLC INTO THE CENTRAL
ATLC W OF 50W INTO THE E GULF OF MEXICO. A SHARP UPPER TROUGH
DIGS S INTO THE E ATLC NEAR 32N25W S TO 14N33W THEN EXTENDS W AS
A SHEAR AXIS ALONG 16N51W OVER THE WINDWARD ISLANDS NEAR SAINT
LUCIA INTO THE S CARIBBEAN. THIS UPPER TROUGH IS SUPPORTING A
1010 MB SURFACE LOW CENTERED NEAR 32N37W WITH A SURFACE TROUGH
EXTENDING S ALONG 28N38W THEN W TO 26N47W AND A STATIONARY
FRONTAL BOUNDARY TO THE E ENTERING THE REGION NEAR 32N25W
EXTENDING ALONG 26N30W TO 25N35W CONTINUING AS A SURFACE TROUGH
TO 24N40W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE WITHIN
150 NM SE OF THE SURFACE TROUGH AND WITHIN 225 NM E OF THE
STATIONARY FRONT.

$$
WALLACE



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