000
AXNT20 KNHC 211730
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SAT MAR 21 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.

...ITCZ...
FROM THE COAST OF SOUTHERN LIBERIA TO 1N20W...CROSSING THE 
EQUATOR ALONG 23W TO 1S38W INTO NORTHEASTERN BRAZIL NEAR 3S46W. 
ISOLATED MODERATE AND DISORGANIZED SHOWERS ARE SOUTH OF 3N 
BETWEEN 25W AND THE EXTREME NORTHEASTERN BRAZIL COAST JUST
WEST OF 50W.
 
...DISCUSSION...

THE GULF OF MEXICO...
MIDDLE LEVEL TO UPPER LEVEL NORTHWESTERLY WIND FLOW COVERS THE 
AREA. THIS FLOW IS ON THE WESTERN SIDE OF A DEEP LAYER ATLANTIC 
OCEAN-TO-EASTERN GULF OF MEXICO TROUGH. THIS TROUGH SUPPORTS A 
COLD FRONT THAT REACHES SOUTH FLORIDA. THE TAIL END OF THE COLD 
FRONT REACHES 26N81W IN SOUTH FLORIDA...A LITTLE WEST OF FORT 
LAUDERDALE. SURFACE NORTHEASTERLY WIND FLOW MOVES FROM THE 
ATLANTIC OCEAN TOWARD THE FLORIDA COAST. A SURFACE RIDGE HAS 
DEVELOPED IN THE GULF OF MEXICO...FROM THE FLORIDA PANHANDLE 
INTO THE ISTHMUS OF TEHUANTEPEC...GENERATING GALE-FORCE WINDS
IN THE GULF OF TEHUANTEPEC ON THE EASTERN PACIFIC OCEAN SIDE
OF MEXICO. 
 
THE CARIBBEAN SEA...
MIDDLE LEVEL TO UPPER LEVEL SOUTHWESTERLY WINDS ARE BLOWING 
ACROSS THE ENTIRE AREA. THE SOUTHWESTERLY FLOW IN THE 
NORTHWESTERN CORNER IS RELATED TO A MIDDLE LEVEL TO UPPER LEVEL 
TROUGH THAT PASSES THROUGH 32N68W IN THE ATLANTIC OCEAN...ACROSS 
THE BAHAMAS...INTO THE EASTERN GULF OF MEXICO. BROKEN LOW LEVEL
TO MIDDLE LEVEL CLOUDS AND POSSIBLE SHOWERS ARE FROM 12N TO 15N
BETWEEN 71W AND 75W...IN THE WINDWARD PASSAGE AND THE JAMAICA 
CHANNEL AND BETWEEN JAMAICA AND CUBA...FROM 17N TO 20N BETWEEN 
79W AND 86W...AND SOUTH OF 19N WEST OF 86W ALONG THE COAST FROM
THE YUCATAN PENINSULA TO THE GULF OF HONDURAS. 

ATLANTIC OCEAN...
A DEEP LAYER TROUGH THAT EXTENDS FROM THE WESTERN ATLANTIC OCEAN 
THROUGH 32N68W INTO THE EASTERN GULF OF MEXICO SUPPORTS A COLD 
FRONT THAT PASSES THROUGH 32N67W TO 28N73W TO THE NORTHERN 
BAHAMAS TO 26N81W IN SOUTH FLORIDA A BIT TO THE WEST OF
FORT LAUDERDALE. A 1012 MB LOW PRESSURE CENTER IS AT THE EASTERN
EDGE OF THE DEEP LAYER TROUGH NEAR 29N65W. A TROUGH EXTENDS FROM 
THE LOW CENTER TO NORTHERN HAITI. ISOLATED MODERATE SHOWERS ARE 
WITHIN 90 NM ON EITHER SIDE OF 29N62W 25N64W 22N65W 19N68W.
STRONG SHOWERS AND POSSIBLE THUNDERSTORMS ARE FROM 30N TO 32N
BETWEEN 61W AND 63W. A WARM FRONT GOES FROM THE LOW CENTER TO 
23N53W. A DISSIPATING COLD FRONT GOES FROM 23N53W TO 22N50W 
26N40W TO 30N35W. A COLD FRONT CONTINUES FROM 30N35W BEYOND 
32N35W. A SURFACE RIDGE TO THE EAST OF THE COLD FRONT PASSES 
THROUGH 33N27W 29N31W 25N31W 19N39W ALL THE WAY TO 23N65W.
A DEEP LAYER TROUGH FROM THE EASTERN ATLANTIC OCEAN INTO THE
CENTRAL ATLANTIC OCEAN SUPPORTS THE ACTIVE PART OF THE COLD
FRONT THAT PASSES THROUGH 32N35W.

$$
MT