000
AXNT20 KNHC 020550
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 AM EDT FRI OCT 02 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...GOES-12 SATELLITE 
IMAGERY THROUGH 0315 UTC AND METEOSAT-8 IMAGERY THROUGH
0530 UTC.

...TROPICAL WAVES...

AN EASTERN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 38W TO THE 
SOUTH OF 12N. STRONG ITCZ SHOWERS AND THUNDERSTORMS ARE
IN ONE OF THE CLUSTERS OF STRONG PRECIPITATION THAT COVERS
THE AREA FROM 9N TO 13N BETWEEN 40W AND 53W. ANY NEARBY 
PRECIPITATION IS IN THE ITCZ. AN ATLANTIC OCEAN TROPICAL WAVE
IS ALONG 52W/53W TO THE SOUTH OF 21N. IT IS NOT EASY TO SEE 
PRECIPITATION WITH THIS WAVE. THE UPPER LEVEL TROUGH THAT
IS NEARBY APPEARS TO BE THE PRIMARY SOURCE OF ATMOSPHERIC 
INSTABILITY NECESSARY FOR THE DEVELOPMENT OF PRECIPITATION.

...THE ITCZ...

FROM 12N17W TO 7N25W 8N38W 8N44W 12N53W NORTHEASTERN VENEZUELA
NEAR 9N64W. STRONG SHOWERS AND THUNDERSTORMS IN INDIVIDUAL 
CLUSTERS WITHIN 60 NM TO 90 NM ALONG 10N14W 8N28W
9N28W...AND 12N41W.

...DISCUSSION...

THE GULF OF MEXICO...
A DEEP LAYER TROUGH THAT IS DIGGING AND DIGGING AND TAKING UP 
LOTS OF SPACE THROUGHOUT THE CENTRAL U.S.A. IS SENDING A 
NORTHEAST-TO-SOUTHWEST ORIENTED UPPER LEVEL RIDGE TO COVER THE
AREA FROM THE FLORIDA PANHANDLE TO THE SOUTHWESTERN CORNER OF 
THE GULF OF MEXICO. THE DEEP LAYER TROUGH THAT HAS BEEN GUIDING
THE FIRST COLD FRONT OF THIS AUTUMN IS ALONG THE LINE THROUGH
30N77W TO 25N80W INTO THE CARIBBEAN SEA NEAR 17N82W. THE TAIL 
END OF A STATIONARY FRONT COVERS THE SOUTHEASTERNMOST CORNER OF 
FLORIDA.

THE CARIBBEAN SEA...
A DEEP LAYER TROUGH EXTENDS FROM THE STRAITS OF FLORIDA NEAR 
25N80W TO 17N82W TO NORTHERN HONDURAS NEAR 15N87W. UPPER LEVEL 
ANTICYCLONIC FLOW THAT IS TO THE SOUTH OF THE CYCLONIC ENVELOPE
WITH THE TROUGH MOVES NORTHWARD FROM THE EASTERN PACIFIC OCEAN
THAT IS TO THE SOUTH OF PANAMA AND IT IS DEFLECTED RAPIDLY 
EASTWARD. SHOWERS AND POSSIBLE THUNDERSTORMS COVER THE CARIBBEAN 
SEA AND THE ATLANTIC OCEAN FROM JAMAICA...ACROSS EXTREME 
SOUTHEASTERN CUBA...TO THE BAHAMAS TO THE SOUTH OF 27N BETWEEN 
70W AND 77W.

THE ATLANTIC OCEAN...
THE DEEP LAYER TROUGH FROM THE WESTERN ATLANTIC OCEAN INTO THE 
CARIBBEAN SEA DOMINATES THE WEATHER NEWS. THE STATIONARY FRONT 
THAT THE TROUGH IS SUPPORTING GOES FROM 31N64W TO 27N70W TO 
26N80W TO 24N81W. AN UPPER LEVEL TROUGH EXTENDS FROM A CYCLONIC 
CIRCULATION CENTER NEAR 24N48W TO 18N49W TO 10N49W. STRONG 
SHOWERS AND THUNDERSTORMS FROM 12N TO 13N BETWEEN 48W AND 50W.
ISOLATED MODERATE SHOWERS COVER THE REST OF THE ATLANTIC OCEAN
FROM 10N TO 26N BETWEEN 40W AND 50W. ISOLATED MODERATE SHOWERS 
ARE IN BETWEEN THE TWO TROUGHS TO THE NORTH OF 23N BETWEEN 47W 
AND 60W. NUMEROUS STRONG SHOWERS AND THUNDERSTORMS THAT ARE IN
THE ITCZ ARE BEING ENHANCED BY THE FACT THAT THIS AREA HAPPENS 
TO BE AT THE BASE OF AN UPPER LEVEL TROUGH THAT EXTENDS FROM
24N26W TO 18N31W TO 10N40W. BROAD LARGE-SCALE DEEP LAYER 
CYCLONIC FLOW COVERS THE ATLANTIC OCEAN TO THE NORTH OF 28N TO
THE EAST OF 50W. THIS EXTENSIVE AREA OF CYCLONIC FLOW SUPPORTS
A COLD FRONT THAT PASSES THROUGH 32N21W 28N30W 27N39W.
A DISSIPATING COLD FRONT GOES FROM 27N39W TO 31N47W. ISOLATED 
MODERATE SHOWERS ARE TO THE NORTHWEST OF THE LINE 31N21W 26N30W 
25N41W. 

$$
MT