000
AXNT20 KNHC 111752
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST WED FEB 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1715 UTC.

...THE ITCZ...

FROM THE CENTRAL COAST OF LIBERIA TO 2N20W...CROSSING THE 
EQUATOR ALONG 27W...TO 1S40W...INTO NORTHEASTERN BRAZIL
NEAR 3S47W. STRONG SHOWERS AND THUNDERSTORMS ARE WITHIN
A 15 NM TO 30 NM RADIUS OF 1N24W...AND FROM 2N TO 3N BETWEEN
26W AND 27W. ISOLATED MODERATE SHOWERS ARE ELSEWHERE SOUTH
OF 5N BETWEEN 16W AND 51W.
 
...DISCUSSION...

THE GULF OF MEXICO...
MIDDLE TO UPPER LEVEL SOUTHWESTERLY WIND FLOW THAT IS ON THE 
WESTERN SIDE OF AN ATLANTIC OCEAN RIDGE COVERS THE AREA.
A DEEP LAYER TROUGH THAT IS MOVING NORTHEASTWARD THROUGH THE 
CENTRAL U.S.A. IS DRIVING THE CURRENT GULF OF MEXICO COLD FRONT. 
THE CURRENT COLD FRONT PASSES THROUGH SOUTHWESTERN LOUISIANA 
NEAR 30N93W TO THE NORTHERN MEXICO COAST NEAR 24N98W TO 23N101W.
SHOWERS ARE WITHIN 30 NM ON EITHER SIDE OF 29N89W 31N88W.
THIS FRONT IS FORECAST TO MOVE TO CENTRAL FLORIDA IN 24 HOURS ON 
THE EASTERN END...AND BECOME STATIONARY ON THE WESTERN END.
THE WESTERN END IS FORECAST TO MOVE NORTHWARD INTO THE NORTHERN
GULF WATERS AS A WARM FRONT IN 48 HOURS. A SURFACE TROUGH IS TO 
THE EAST AND SOUTHEAST OF THE FRONT...ALONG 26N95W TO A 1011 MB
LOW PRESSURE CENTER NEAR 22N95W...TO THE ISTHMUS OF TEHUANTEPEC
AND INTO CENTRAL AMERICA TO NORTHWESTERN NICARAGUA.

THE CARIBBEAN SEA...
BROAD LARGE SCALE UPPER LEVEL SOUTHERLY AND SOUTHWESTERLY FLOW 
MOVE FROM SOUTH AMERICA INTO THE CENTRAL AND EASTERN CARIBBEAN 
SEA...SOUTH OF 10N81W 16N75W BEYOND 16N60W. BROAD UPPER LEVEL
EASTERLY FLOW IS NORTH OF 16N...GETTING CAUGHT UP IN AN UPPER 
LEVEL RIDGE THAT STRETCHES NORTHEASTWARD FROM WESTERN CUBA 
BEYOND THE NORTHERN BAHAMAS. DRY AIR IN SUBSIDENCE IS EVERYWHERE 
EXCEPT UNDER THE FLOW FROM SOUTH AMERICA NORTHWARD. A LOW LEVEL 
TROUGH ALONG THE LINE FROM 20N67W TO THE EASTERN DOMINICAN 
REPUBLIC TO 16N70W HAS HELPED TO PRODUCE PRECIPITATION FROM THE 
VIRGIN ISLANDS TO PUERTO RICO DURING THE LAST 24 HOURS.

THE ATLANTIC OCEAN...
LARGE SCALE UPPER LEVEL ANTICYCLONIC FLOW AROUND A RIDGE COVERS 
THE AREA TO THE WEST OF A SHORTWAVE TROUGH THAT IS ALONG THE 
LINE THROUGH 32N44W TO 29N46W TO 25N54W. THIS TROUGH IS MOVING 
TOWARD THE DEEP LAYER TROUGH THAT HAS BEEN AROUND FOR MOST OF
A WEEK...NOW PASSING THROUGH 32N31W TO 26N31W TO 20N45W. THE 
DEEP LAYER TROUGH SUPPORTS THE COLD FRONT THAT PASSES THROUGH 
32N36W TO 28N41W TO 23N52W. A TROUGH CONTINUES FROM 23N52W TO 
22N61W TO 22N65W. BROAD SURFACE ANTICYCLONIC FLOW IS NORTH AND
NORTHWEST OF THE COLD FRONT/TROUGH AROUND A 1030 MB HIGH PRESSURE
CENTER NEARLY RIGHT ON TOP OF BERMUDA. A SURFACE TROUGH IS TO
THE SOUTHEAST OF THE COLD FRONT ALONG 25N42W 20N46W. A SMALL
1025 MB HIGH PRESSURE CENTER IS NEAR 22N40W. BROAD SURFACE
ANTICYCLONIC FLOW IS NORTH OF 28N EAST OF 30W AROUND A 1033 MB
HIGH PRESSURE CENTER NEAR 42N15W.

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