[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 120558
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT MON OCT 12 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
0315 UTC.

...TROPICAL WAVES...

TROPICAL WAVE EXTENDS FROM 16N42W TO 8N45W MOVING W 10-15 KT.
WAVE HAS BECOME ILL-DEFINED AS SMALL CYCLONIC CIRCULATIONS ARE
SPINNING OFF TO THE NE FROM THE N PORTION OF THE TROPICAL WAVE
CAUGHT UP IN AN UPPER TROUGH. ALTHOUGH THE WAVE IS TILTED TOWARD
A MOISTURE MAXIMUM IN THE TOTAL PRECIPITABLE WATER IMAGERY...
THERE IS NO ASSOCIATED SHOWERS OR DEEP CONVECTION.

TROPICAL WAVE IS ALONG 79W/80W S OF 18N MOVING W NEAR 15 KT.
WAVE IS EMBEDDED WITHIN A DEEP LAYER MOISTURE MAXIMUM IN THE
TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ARE S OF 14N TO OVER CENTRAL AMERICA BETWEEN
77W-83W.

...THE ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 10N14W 8N23W 13N41W 7N59W. THE
ITCZ IS NOT VERY ACTIVE TONIGHT WITH SMALL CLUSTERS OF SCATTERED
MODERATE/ISOLATED STRONG CONVECTION FROM 5N-8N BETWEEN 16W-20W
AND FROM 8N-10N BETWEEN 20W-31W.

...DISCUSSION...

GULF OF MEXICO...
THE STATIONARY FRONT ACROSS THE GULF HAS BACKED N AS A WARM
FRONT EXTENDING FROM THE W ATLC ACROSS N FLORIDA OVER APALACHEE
BAY AND PANAMA CITY ALONG 30N87W THEN THE MISSISSIPPI DELTA OF
LOUISIANA TO JUST OFF THE COAST NEAR CORPUS CHRISTI TEXAS AND S
OVER BROWNSVILLE INTO NE MEXICO. THE FRONT APPEARS TO BE
STALLING AGAIN AS IT CONTINUES TO WEAKEN WITH ISOLATED SHOWERS N
OF THE FRONT TO INLAND OVER THE GULF COAST STATES. A BROAD UPPER
RIDGE ANCHORED OVER THE SE GULF NEAR 26N87W DOMINATES THE ENTIRE
BASIN PROVIDING DIFFLUENCE ALOFT OVER THE W GULF TO GENERATE
SCATTERED SHOWERS/ISOLATED THUNDERSTORMS WITHIN 75 NM OF LINE
FROM 26N97W INTO THE BAY OF CAMPECHE AND OVER S MEXICO NEAR
18N94W WITH ISOLATED SHOWERS/THUNDERSTORMS OVER THE SE GULF S OF
26N E OF 83W. THE REMAINDER OF THE GULF IS EXPERIENCING
GENERALLY FAIR WEATHER TONIGHT. A SURFACE RIDGE WILL BUILD
ACROSS THE GULF AS THE FRONTAL SYSTEM CONTINUES TO WEAKEN.

CARIBBEAN SEA...
THE TROPICAL WAVE ALONG 79W/80W IS RESPONSIBLE FOR THE ACTIVITY
IN THE SW CARIBBEAN. A SURFACE TROUGH...REMNANTS OF HENRI...
EXTENDS FROM THE TURKS AND CAICOS NEAR 22N73W ACROSS THE E TIP
OF CUBA TO NEAR 18N76W WHILE A SECOND SURFACE TROUGH...REMNANT
FRONTAL BOUNDARY...EXTENDS ACROSS THE VIRGIN ISLANDS NEAR 19N63W
TO S OF PUERTO RICO NEAR 17N67W. BROAD UPPER RIDGE THAT COVERS
MOST OF THE ATLC IS GIVING THE CARIBBEAN UPPER EASTERLY WINDS
AND COUPLE OF THE SURFACE TROUGHS ARE ARE PRODUCING SCATTERED
SHOWERS/ISOLATED THUNDERSTORMS OVER THE GREATER ANTILLES FROM
16N-20N FROM 60W-80W WITH ISOLATED SHOWERS/THUNDERSTORMS FROM
18N-22N BETWEEN 80W-84W. VERY DRY AIR AND SUBSIDENCE IS OVER THE
E CARIBBEAN S OF 16N E OF 77W GIVING THE AREA CLEAR SKIES
TONIGHT.

ATLANTIC OCEAN...
A STATIONARY FRONT ENTERS THE REGION NEAR 32N76W CONTINUING
ACROSS NE FLORIDA NEAR DAYTONA BEACH CONTINUING AS A WARM FRONT
INTO THE GULF OF MEXICO. BROAD UPPER RIDGE DOMINATES THE ATLC W
OF 40W ANCHORED NEAR 26N61W WHICH HAS STALLED THE EASTERLY
MOVEMENT OF THE FRONT IN THE REGION. A SURFACE HIGH RIDGE COVERS
THE W ATLC N OF 23N W OF 50W TO OVER THE FLORIDA PENINSULA
ANCHORED BY A 1021 MB HIGH NEAR 29N68W. A SURFACE TROUGH...
REMNANTS OF HENRI...IS THE FAR SW ATLC EXTENDING FROM THE TURKS
AND CAICOS NEAR 22N73W ACROSS THE E TIP OF CUBA INTO THE
CARIBBEAN. A SHARP UPPER TROUGH DIGS S INTO THE E ATLC NEAR
32N32W S TO 16N34W THEN EXTENDS W AS A SHEAR AXIS ALONG 15N45W
OVER TRINIDAD AND THE N PORTION OF SOUTH AMERICA SUPPORTING A
NEAR-STATIONARY FRONTAL BOUNDARY THAT ENTERS THE REGION NEAR
32N27W EXTENDING ALONG 25N33W 18N48W TO 18N53W CONTINUING AS A
SURFACE TROUGH ALONG 19N61W ACROSS THE VIRGIN ISLANDS INTO THE
NE CARIBBEAN TO NEAR 17N67W. SCATTERED SHOWERS/ISOLATED
THUNDERSTORMS ARE WITHIN 150 NM E OF THE FRONT N OF 23N AND
WITHIN 75 NM EITHER SIDE OF THE SURFACE TROUGH W OF 61W.

$$
WALLACE



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