[Tropical] Tropical Weather Discussion

[EMWIN Server]

AXNT20 KNHC 110558
TWDAT

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT SUN OCT 11 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 FOR GOES-12 IMAGERY...AND THROUGH 0530 UTC
FOR METEOSAT-8 IMAGERY.

...TROPICAL WAVES...

AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 17N37W 14N39W 9N40W
MOVING WEST 10 KT OR LESS. THIS WAVE HAS BEEN SLOWING DOWN IN
SPEED DURING THE LAST 24 HOURS. IT APPEARS THAT ITS WESTWARD
PROGRESSION IS BEING BLOCKED BY A MIDDLE LEVEL TROUGH THAT IS
ALONG 19N33W 14N45W 10N57W.

A CARIBBEAN SEA TROPICAL WAVE IS ALONG 73W TO THE SOUTH OF 16N
MOVING WESTWARD 10 TO 15 KT. SHOWERS AND POSSIBLE THUNDERSTORMS
FROM 13N TO 15N BETWEEN 73W AND 75W.

A TROPICAL WAVE IS MOVING ACROSS SOUTHEASTERN MEXICO BETWEEN THE
SOUTHWESTERN YUCATAN PENINSULA AND THE ISTHMUS OF TEHUANTEPEC...
MOVING WESTWARD 10 TO 15 KT. IT IS NOT EASY TO RELATE ANY
PRECIPITATION DIRECTLY JUST TO THIS WAVE.

...THE ITCZ...

FROM 9N13W TO 8N20W TO 12N37W TO 12N42W TO THE NORTHERN COAST OF
SURINAME TO 7N63W IN EASTERN VENEZUELA. NUMEROUS STRONG SHOWERS
AND THUNDERSTORMS ARE FROM 12N TO 13N BETWEEN 29W AND 31W...
WITHIN A 30 NM RADIUS OF 10N43W...9N48W...AND 8N50W. WARMING
CLOUD TOP TEMPERATURES AND WEAKENING BUT POSSIBLY LINGERING
PRECIPITATION FROM 10N TO 12N BETWEEN 41W AND 43W. SHOWERS ARE
POSSIBLE WITHIN 180 NM ON EITHER SIDE OF 7N12W 7N23W 12N31W...
AND WITHIN 60 NM ON EITHER SIDE OF 13N38W 10N45W 6N56W.

...DISCUSSION...

THE GULF OF MEXICO...
THE UPPER LEVEL ATMOSPHERIC SUPPORT FOR THE CURRENT STATIONARY
FRONT IS PRETTY MUCH NON-EXISTENT. SOME OF THE FLOW IN THE NORTH
CENTRAL GULF WATERS IS SOUTHWESTERLY. SOME OF THE FLOW IN THE
CENTRAL GULF WATERS IS ANTICYCLONIC. AN UPPER LEVEL TROUGH RUNS
FROM ONE CYCLONIC CIRCULATION CENTER IS NEAR THE BAY OF CAMPECHE
BETWEEN THE SOUTHWESTERN PART OF THE YUCATAN PENINSULA AND THE
ISTHMUS OF TEHUANTEPEC...AND A SECOND CYCLONIC CENTER THAT IS
NEAR 13N96W...THAT IS ABOUT 200 NM TO THE SOUTH-SOUTHWEST OF
THE GULF OF TEHUANTEPEC. STRONG SHOWERS AND THUNDERSTORMS ARE
IN THE GULF AND ISTHMUS OF TEHUANTEPEC. THE STATIONARY FRONT
PASSES THROUGH THE FLORIDA PANHANDLE TO THE NORTH CENTRAL GULF
WATERS...TO 26N95W...AND TO COASTAL MEXICO NEAR 20N97W.
DISORGANIZED ISOLATED MODERATE TO STRONG SHOWERS AND POSSIBLE
THUNDERSTORMS ARE FROM 21N TO 26N BETWEEN 95W AND 97W.

THE CARIBBEAN SEA...
THE LINE OF UPPER LEVEL DIFFLUENT FLOW THAT SEPARATES THE GULF
OF MEXICO CYCLONIC FLOW AND THE UPPER LEVEL ANTICYCLONIC FLOW
THAT COVERS THE WESTERN CARIBBEAN SEA IS MORE OR LESS ALONG
86W/87W. ANTICYCLONIC FLOW GOES FROM CENTRAL AMERICA TO JAMAICA
ALONG 77W. A MASS OF DRY AIR IN SUBSIDENCE IS ROLLING ACROSS THE
CARIBBEAN SEA FROM EAST-TO-WEST BETWEEN 60W AND 77W. THE ONLY
SIGNIFICANT DEEP CONVECTIVE PRECIPITATION THAT IS SURVIVING THE
DRY AIR IS THE SHOWER/THUNDERSTORM ACTIVITY FROM 13N TO 15N
BETWEEN 73W AND 75W THAT ACCOMPANIES THE 73W TROPICAL WAVE.

THE ATLANTIC OCEAN...
THE REMNANT OF HENRI IS A 1013 MB LOW PRESSURE CENTER THAT
IS NEAR 20N70W. THE LITTLE BIT OF PRECIPITATION THAT WAS
ACCOMPANYING THE REMNANT OF HENRI HAS BEEN OVERWHELMED
BY THE DRY AIR IN SUBSIDENCE THAT SURROUNDS IT. UPPER LEVEL
ANTICYCLONIC FLOW AND DRY AIR IN SUBSIDENCE COVER THE AREA
TO THE NORTH OF 20N TO THE WEST OF 50W. EVEN MORE UPPER LEVEL
ANTICYCLONIC FLOW CONTINUES TO THE NORTH OF 20N BETWEEN 40W
AND 50W...AS SOME OF THIS FLOW HEADS TOWARD THE TROUGH THAT
PASSES THROUGH 32N38W 23N39W TO 19N42W. THIS TROUGH SUPPORTS
THE STATIONARY FRONT THAT PASSES THROUGH 32N37W TO 25N40W AND
22N50W. A SURFACE TROUGH CONTINUES FROM 22N50W TO 21N55W AND
21N62W. ISOLATED MODERATE SHOWERS ARE STAYING ALIVE IN THE DRY
AIR FROM 19N TO 21N BETWEEN 50W AND 63W. SHOWERS AND ISOLATED
STRONG THUNDERSTORMS COVER THE AREA FROM 23N TO 32N BETWEEN
28W AND 40W.

$$
MT





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