000
AXNT20 KNHC 150552
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST THU JAN 15 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 0515 UTC.

...THE ITCZ...

FROM LIBERIA NEAR 7N11W TO 2N20W TO 1N31W...CROSSING THE EQUATOR 
ALONG 38W...INTO NORTHEASTERN BRAZIL NEAR 3S45W. SCATTERED 
STRONG SHOWERS AND THUNDERSTORMS FROM 2N TO 4N BETWEEN 4W AND 
14W...SOUTH OF 4N BETWEEN 16W AND 23W...FROM 3N TO 4N BETWEEN 
28W AND 30W. SHOWERS ARE POSSIBLE FROM 6N TO 10N BETWEEN 32W
AND 36W...AND SOUTH OF 7N BETWEEN 40W AND 55W.

...DISCUSSION...

THE GULF OF MEXICO...
THE DEEP LAYER TROUGH THAT BROUGHT THE MOST RECENT COLD FRONT
TO THE GULF OF MEXICO HAS MOVED OUT OF THE AREA...TO THE 
ATLANTIC OCEAN...ALONG THE U.S.A. EAST COAST. THE TROUGH HAS 
BECOME ELONGATED...STRETCHED OUT ALONG A NORTHEAST-TO-SOUTHWEST 
LINE. UPPER LEVEL SOUTHWESTERLY WIND FLOW COVERS THE AREA. 
MOISTURE AT SEVERAL LEVELS IN THE ATMOSPHERE COVERS MOST OF THE
AREA. THE ONLY AMOUNTS OF DRY AIR IN SUBSIDENCE ARE NORTH OF 27N.
SURFACE HIGH PRESSURE HAS SETTLED INTO THE AREA. GALE-FORCE WIND 
CONDITIONS ARE BEING EXPERIENCED IN THE GULF OF TEHUANTEPEC ON 
THE EASTERN PACIFIC OCEAN SIDE OF MEXICO.

THE CARIBBEAN SEA...
MIDDLE TO UPPER LEVEL DRY AIR IN SUBSIDENCE COVERS THE AREA
EAST OF 80W. BROAD UPPER LEVEL ANTICYCLONIC FLOW IS IN PLACE
AS MIDDLE TO UPPER LEVEL CYCLONIC FLOW STARTS TO MOVE INTO THE 
AREA EAST OF 65W. THE CYCLONIC FLOW IS AROUND A CUT-OFF CYCLONIC 
CIRCULATION CENTER IN THE ATLANTIC OCEAN NEAR 14N50W. A TROUGH
EXTENDS FROM THE CYCLONIC CENTER TO 13N64W. THE SOUTHERN END OF
AN ATLANTIC OCEAN-TO-CARIBBEAN SEA COLD FRONT PASSES OVER CUBA
NEAR 21N77W TO THE CAYMAN ISLANDS...CONTINUING AS A STATIONARY
FRONT FROM THE CAYMAN ISLANDS TO THE ISLAS DE LA BAHIA OFF THE 
COAST OF HONDURAS. WINDS FROM THE NORTHEAST TO EAST RANGING
FROM 20 TO 30 KTS AND SEA HEIGHTS RANGING FROM 8 TO 12 FT ARE
FORECAST FOR THE NEXT 48 HOURS FROM 10N TO 18N EAST OF 82W. THE 
WINDS AND SEAS ARE RELATED TO A TIGHT SURFACE PRESSURE GRADIENT 
BETWEEN HIGH PRESSURE NORTH OF THE AREA AND THE SEMI-PERMANENT 
SURFACE LOW PRESSURE IN COLOMBIA AND PANAMA.

THE REST OF THE ATLANTIC OCEAN EAST OF 60W...
THE DEEP LAYER TROUGH THAT BROUGHT THE MOST RECENT COLD FRONT
TO THE GULF OF MEXICO HAS MOVED OUT OF THE AREA...TO THE 
ATLANTIC OCEAN...ALONG THE U.S.A. EAST COAST. THE TROUGH HAS 
BECOME ELONGATED...STRETCHED OUT ALONG A NORTHEAST-TO-SOUTHWEST 
LINE. AN UPPER LEVEL RIDGE IS ALONG THE LINE FROM THE MONA 
PASSAGE BEYOND 32N43W. A MIDDLE TO UPPER LEVEL CYCLONIC 
CIRCULATION CENTER IS NEAR 14N50W. A TROUGH EXTENDS FROM THIS
CENTER TO 13N64W IN THE SOUTHEASTERN CARIBBEAN SEA. CYCLONIC 
FLOW AROUND THIS CENTER COVERS THE ATLANTIC OCEAN FROM 8N TO 23N 
BETWEEN 45W AND 60W ON CURRENT WATER VAPOR SATELLITE IMAGERY.
A SURFACE TROUGH IS ALONG 50W FROM 9N TO 19N. SCATTERED MODERATE 
SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE FROM 14N TO 18N 
BETWEEN 44W AND 53W...AND FROM 16N TO 17N BETWEEN 37W AND 40W.
A DEEP LAYER TROUGH IS DIGGING SOUTHWARD TO THE CANARY ISLANDS. 
THIS TROUGH SUPPORTS A COLD FRONT THAT PASSES FROM THE MADEIRA 
ARCHIPELAGO TO 30N22W. PRECIPITATION IS POSSIBLE NORTH OF 30N 
BETWEEN 14W AND 17W. A SURFACE RIDGE PASSES THROUGH 32N40W TO 
28N55W TO 26N66W.

$$
MT