000
AXNT20 KNHC 130554
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST TUE JAN 13 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 SIERRA LEONE NEAR 8N12W TO 5N20W TO 4N30W TO 3N40W...
CROSSING THE EQUATOR ALONG 46W...INTO NORTHEASTERN BRAZIL
NEAR 2S48W. STRONG SHOWERS AND THUNDERSTORMS ARE FROM 2N
TO 4N BETWEEN 17W AND 24W...AND FROM 4N TO 5N BETWEEN 27W
AND 31W. ISOLATED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS
ARE ELSEWHERE SOUTH OF 8N BETWEEN 24W AND 50W.
 
...DISCUSSION...

THE GULF OF MEXICO...AND THE ATLANTIC OCEAN WEST OF BERMUDA...
A DEEP LAYER TROUGH IS DIGGING SOUTHWARD...FROM THE NORTH 
CENTRAL U.S.A. INTO SOUTH CENTRAL TEXAS. THIS FEATURE SUPPORTS 
COLD FRONTS THAT STILL ARE WELL NORTH OF THE AREA IN THE TEXAS
AND MUCH MUCH FARTHER TO THE NORTH. A SHALLOW STATIONARY FRONT
STRETCHES FROM LAKE OKEECHOBEE FLORIDA INTO THE CENTRAL GULF
OF MEXICO...TOWARD THE SOUTHWESTERN CORNER OF THE AREA. THIS
FRONT IS UNDERNEATH UPPER LEVEL SOUTHWESTERLY WIND FLOW THAT
IS PREVALENT EVERYWHERE EXCEPT FOR THE TEXAS COASTAL WATERS.
SCATTERED MODERATE SHOWERS AND POSSIBLE THUNDERSTORMS IS IN
THE NORTH CENTRAL GULF WATERS. THE STATIONARY FRONT CONTINUES
NORTHEAST OF LAKE OKEECHOBEE FLORIDA...TO THE ATLANTIC OCEAN
NEAR 29N80W...BECOMING WARM FROM 29N80W TO 29N74W...AND THEN
AS A COLD FRONT FROM 29N74W THROUGH 30N70W AND NORTHEASTWARD 
BEYOND BERMUDA. GALE-FORCE WINDS ARE FORECAST TO DEVELOP TO
THE NORTH OF THE COLD FRONT DURING THE NEXT 24 HOURS. AT LEAST
TWO MORE FRONTAL BOUNDARIES TO MOVE THROUGH THE GULF WATERS
DURING THE NEXT FEW DAYS. 

THE CARIBBEAN SEA...
MIDDLE TO UPPER LEVEL DRY AIR IN SUBSIDENCE SURROUNDS A MIDDLE
TO UPPER LEVEL TROUGH THAT PASSES THROUGH THE ATLANTIC OCEAN 
FROM 15N52W TO 13N68W. UPPER LEVEL ANTICYCLONIC FLOW COVERS THE 
AREA WEST OF 70W. THIS ANTICYCLONIC FLOW IS PART OF A BROADER
UPPER LEVEL RIDGE THAT EXTENDS FROM THE WESTERN CARIBBEAN SEA 
INTO THE CENTRAL ATLANTIC OCEAN NORTHEASTWARD BEYOND 32N53W.
A TIGHT SURFACE PRESSURE GRADIENT BETWEEN HIGH PRESSURE NORTH
OF THE AREA AND THE SEMI-PERMANENT SURFACE LOW PRESSURE IN
COLOMBIA AND PANAMA IS PRODUCING MODERATE TO STRONG TRADEWINDS 
WITH OCCASIONAL GUSTS TO GALE FORCE ACROSS THE BASIN. THE 
COMPARATIVELY FASTEST WINDS USUALLY ARE NEAR THE COAST OF
COLOMBIA. THE NEXT COLD FRONT IS FORECAST TO REACH WESTERN
CUBA AND THE NORTHWESTERN CARIBBEAN SEA LATE TUESDAY.
THE SAME FRONT WILL EXTEND FROM CENTRAL CUBA TO HONDURAS
ON WEDNESDAY.

THE ATLANTIC OCEAN...
A MIDDLE TO UPPER LEVEL TROUGH EXTENDS FROM 26N37W TO 15N52W
INTO THE SOUTHEASTERN CARIBBEAN SEA NEAR 13N68W. MIDDLE TO
UPPER LEVEL DRY AIR IN SUBSIDENCE SURROUNDS THIS TROUGH...FROM
6N IN GUYANA AND VENEZUELA TO 30N BETWEEN 40W AND 70W. ISOLATED
MODERATE SHOWERS ARE FROM 10N TO 16N BETWEEN 40W AND 50W...
AND FROM 13N TO 17N BETWEEN 45W AND 52W. A SURFACE RIDGE
PASSES THROUGH 32N38W TO 28N61W TO 27N74W.

$$
MT