000
AXNT20 KNHC 121727
TWDAT 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN APR 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1645 UTC.

...THE ITCZ...
FROM THE COAST OF LIBERIA NEAR 5N10W TO 2N20W...CROSSING THE
EQUATOR ALONG 30W...AND GOING INTO NORTHEASTERN BRAZIL NEAR
4S45W. ISOLATED AND DISORGANIZED MODERATE SHOWERS ARE TO THE 
SOUTH OF 5N BETWEEN 7W AND 40W. STRONG SHOWERS AND THUNDERSTORMS 
ARE WITHIN 30 NM TO 60 NM ON EITHER SIDE OF THE EQUATOR BETWEEN
40W AND 46W.

...DISCUSSION...

THE GULF OF MEXICO...
A DEEP LAYER TROUGH IN WEST TEXAS IS DRIVING A COLD FRONT THAT 
IS MOVING THROUGH TEXAS. THIS TEXAS COLD FRONT IS CONNECTED TO
A DEVELOPING WARM FRONT ACROSS EAST TEXAS/SOUTHWESTERN LOUISIANA
AND AN ALREADY-EXISTING STATIONARY FRONT THAT EXTENDS FROM 
SOUTHWESTERN LOUISIANA INTO THE NORTHERN GULF COASTAL WATERS... 
ACROSS THE GULF WATERS TO THE FLORIDA WEST COAST NEARLY DUE WEST
OF ORLANDO TOWARD CAPE CANAVERAL. A COLD FRONT CONTINUES FROM
CAPE CANAVERAL EASTWARD INTO THE ATLANTIC OCEAN. STRONG SHOWERS 
AND THUNDERSTORMS HAVE BEGUN TO DEVELOP FROM EAST TEXAS BEYOND
NORTHWESTERN LOUISIANA. SOME SHOWERS ARE DEVELOPING FROM 26N TO 
29N BETWEEN 91W AND 94W TO THE SOUTH OF LOUISIANA. THE STATIONARY
FRONT BETWEEN FLORIDA AND 90W IS MARKED BY A THIN LINE OF CLOUDS.
AN UPPER LEVEL RIDGE IS ALONG 84W/85W IN BETWEEN THE WEST TEXAS 
TROUGH AND A WESTERN ATLANTIC OCEAN DEEP LAYER TROUGH.

THE CARIBBEAN SEA...
UPPER LEVEL ANTICYCLONIC FLOW COVERS THE AREA TO THE WEST OF 
66W THANKS TO THE UPPER LEVEL 84W/85W RIDGE THAT ALSO SPANS THE 
GULF OF MEXICO. DEEP LAYER CYCLONIC FLOW CUTS INTO THE EASTERN
CARIBBEAN SEA TO THE EAST OF 66W THANKS TO THE DEEP LAYER 
WESTERN ATLANTIC OCEAN TROUGH THAT REACHES AS FAR TO THE SOUTH 
AS DOMINICA. A WEAK SURFACE PRESSURE GRADIENT EXISTS ACROSS THE
AREA. SHOWERS ARE POSSIBLE TO THE SOUTH OF 17N BETWEEN 60W AND 
62W IN CLUSTERS OF BROKEN LOW CLOUDS.
 
THE ATLANTIC OCEAN...
A WESTERN ATLANTIC OCEAN DEEP LAYER TROUGH SUPPORTS THE ATLANTIC 
OCEAN COLD FRONT THAT PASSES THROUGH THE AREA JUST TO THE WEST 
OF BERMUDA AND CONTINUES TO 29N70W 27N78W AND TO THE FLORIDA 
COAST NEAR CAPE CANAVERAL. ISOLATED MODERATE SHOWERS ARE IN 
FRONT OF THE COLD FRONT...TO THE NORTH OF 26N TO THE EAST OF 
76W. OTHER SHOWERS ARE FROM 26N TO 27N BETWEEN 67W AND 69W...
FROM 26N TO 32N BETWEEN 58W AND 62W. SHOWERS ARE POSSIBLE FROM 
22N TO 26N BETWEEN 60W AND 68W. A SURFACE RIDGE IS ALONG THE 
LINE THROUGH 32N45W TO 29N52W 25N61W INTO THE NORTHWESTERN 
CARIBBEAN SEA NEAR 20N83W. AN UPPER LEVEL RIDGE IS ALONG 31N26W 
TO 31N56W. BROAD LARGE-SCALE UPPER LEVEL ANTICYCLONIC FLOW IS
TO THE SOUTH OF 25N TO THE EAST OF 60W. 

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MT