000
AXNT20 KNHC 310512
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
105 AM EST MON JAN 31 2011

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 
0445 UTC.

...THE ITCZ...

FROM THE CENTRAL COAST OF LIBERIA TO 4N20W 3N30W 2N40W...
CROSSING THE EQUATOR ALONG 44W...INTO NORTHEASTERN BRAZIL
NEAR 2S47W. WIDELY SCATTERED STRONG RAINSHOWERS AND
THUNDERSTORMS ARE FROM 4N TO 5N BETWEEN 11W AND 15W...
AND FROM 1N TO 3N BETWEEN 10W AND 22W. ISOLATED MODERATE
RAINSHOWERS AND LOCALLY STRONG THUNDERSTORMS ARE ELSEWHERE
TO THE SOUTH OF 5N BETWEEN 23W AND 50W.

...DISCUSSION...

THE GULF OF MEXICO...

AN UPPER LEVEL SHORTWAVE TROUGH IS MOVING FROM EAST TEXAS INTO 
LOUISIANA AND PARTS OF THE NORTH CENTRAL GULF OF MEXICO. THIS
TROUGH IS ASSOCIATED WITH A FRONTAL BOUNDARY THAT STRETCHES FROM 
NORTHEASTERN TEXAS TO CENTRAL TEXAS TO THE FAR WEST OF TEXAS.
RAINSHOWERS AND THUNDERSTORMS HAVE FORMED AND/OR HAVE BEEN 
FORMING ALONG AN OUTFLOW BOUNDARY THAT IS IN THE NORTH CENTRAL 
GULF OF MEXICO...CLOSE TO THE LOUISIANA COAST. UPPER LEVEL 
WESTERLY WIND FLOW COVERS THE REST OF THE AREA. THE WESTERN END 
OF A SURFACE RIDGE IS ALONG 28N87W TO AN ATLANTIC OCEAN 1023 MB 
HIGH PRESSURE CENTER THAT IS NEAR 29N75W.

THE CARIBBEAN SEA...

UPPER LEVEL WESTERLY FLOW MOVES ON TOP OF LOW LEVEL TO MIDDLE 
LEVEL EASTERLY FLOW...IN AN AREA THAT ALSO IS COVERED BY DRY AIR 
IN SUBSIDENCE IN THE UPPER LEVELS OF THE ATMOSPHERE. BROKEN TO 
OVERCAST LOW CLOUDS AND POSSIBLE RAIN ARE TO THE EAST OF 19N60W
15N64W 11N61W...FROM THE VENEZUELA COAST TO 14N BETWEEN 62W AND 
65W...WITHIN 60 NM TO 90 NM ON EITHER SIDE OF 22N63W FROM THE 
ATLANTIC OCEAN TO 19N66W PASSING OVER PUERTO RICO TO 16N68W...
FROM 17N TO 21N INCLUDING SOUTHEASTERN CUBA BETWEEN 74W AND 
82W...AND TO THE SOUTH OF 17N BETWEEN 79W AND 87W INCLUDING
IN EASTERN HONDURAS AND NORTHWESTERN NICARAGUA.

THE ATLANTIC OCEAN...

A DEEP LAYER CENTRAL ATLANTIC OCEAN TROUGH PASSES THROUGH 32N53W 
TO 26N58W TO 20N60W. THIS TROUGH SUPPORTS THE COLD FRONT THAT 
PASSES THROUGH 32N50W TO 26N60W. A STATIONARY FRONT CONTINUES 
FROM 26N60W TO 24N66W 23N71W. WIDELY SCATTERED MODERATE 
RAINSHOWERS ARE WITHIN 60 NM ON EITHER SIDE OF 27N57W BEYOND
32N51W. RAINSHOWERS ARE POSSIBLE WITHIN 90 NM ON EITHER SIDE
OF 27N57W 25N63W 24N72W. A SURFACE RIDGE EXTENDS FROM A 1025 MB 
HIGH PRESSURE CENTER THAT IS NEAR 31N62W TO A 1023 MB HIGH 
PRESSURE CENTER THAT IS NEAR 29N75W. SURFACE ANTICYCLONIC WIND 
FLOW MOVES AROUND A RIDGE THAT PASSES THROUGH 32N39W TO 26N51W 
TO 21N58W. A SURFACE TROUGH IS ALONG 22N25W 20N27W 17N32W.
THIS TROUGH IS THE REMNANT OF A FRONTAL BOUNDARY WITH TWO LOW 
PRESSURE CENTERS DURING THE LAST 3 TO 4 DAYS. NO DEEP CONVECTIVE 
PRECIPITATION IS APPARENT WITH THE TROUGH.

FOR ADDITIONAL INFORMATION PLEASE VISIT
HTTP://WWW.HURRICANES.GOV/MARINE

$$
MT