000
AXNT20 KNHC 211154
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL  
705 AM EST FRI JAN 21 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1115 UTC.

...THE ITCZ...

FROM CENTRAL COASTAL LIBERIA TO 6N16W...CROSSING THE EQUATOR 
ALONG 29W...INTO NORTHEASTERN BRAZIL NEAR 4S42W. ISOLATED 
MODERATE RAINSHOWERS AND LOCALLY STRONG THUNDERSTORMS ARE
TO THE SOUTH OF 5N TO THE EAST OF 51W.

...DISCUSSION...

THE GULF OF MEXICO...
A LONGWAVE UPPER LEVEL TROUGH IS MOVING THROUGH THE OHIO VALLEY 
OF THE U.S.A....AND SWINGING THROUGH MISSISSIPPI...LOUISIANA...
AND TEXAS INTO NORTHERN MEXICO. THE UPPER LEVEL SOUTHWESTERLY 
WIND FLOW THAT COVERS THE GULF OF MEXICO IS A COMBINATION OF
THE FLOW THAT IS TO THE SOUTHEAST OF THE UPPER LEVEL TROUGH
AND BROAD UPPER LEVEL ANTICYCLONIC WIND FLOW THAT ALSO SPANS
THE CARIBBEAN SEA. THE TROUGH SUPPORTS A COLD FRONT THAT IS 
MOVING THROUGH THE FLORIDA PANHANDLE INTO THE WEST CENTRAL
GULF OF MEXICO...TO THE MEXICO COAST NEAR 23N98W. RAINSHOWERS 
AND THUNDERSTORMS COVER THE GULF OF MEXICO FROM 24N TO 28N
BETWEEN WESTERN FLORIDA AND 88W. BROKEN TO OVERCAST LOW CLOUDS 
AND POSSIBLE FOG/HAZE ARE IN THE FLORIDA PANHANDLE AND 
NORTHEASTERN FLORIDA. BROKEN TO OVERCAST LOW CLOUDS ARE TO
THE NORTH AND NORTHWEST OF THE COLD FRONT. A SURFACE TROUGH
IS WITHIN 120 NM TO 180 NM TO THE SOUTHEAST OF THE COLD
FRONT...TO THE NORTH OF 23N.

THE CARIBBEAN SEA...
BROAD UPPER LEVEL ANTICYCLONIC WIND FLOW SPANS THE AREA.
DRY AIR IN SUBSIDENCE IN WATER VAPOR IMAGERY COVERS THE ENTIRE 
AREA. A SURFACE TROUGH IS ALONG 69W/70W FROM 9N IN COASTAL 
VENEZUELA TO 16N. RAINSHOWERS ARE POSSIBLE IN THE BROKEN TO 
OVERCAST LOW LEVEL TO MIDDLE LEVEL CLOUDS THAT COVER THE WATERS 
FROM COASTAL VENEZUELA AND COLOMBIA TO 17N BETWEEN 69W AND 74W. 
RAINSHOWERS ARE POSSIBLE ELSEWHERE IN OTHER CLUSTERS OF CLOUDS
BETWEEN 59W AND 67W...IN THE ATLANTIC OCEAN WATERS TO THE SOUTH 
OF 22N BETWEEN 60W AND 74W REACHING THE NORTHERN SHORES OF THE 
GREATER ANTILLES...AND TO THE NORTH OF 18N BETWEEN WESTERN 
JAMAICA AND 83W IN THE NORTHWESTER CORNER OF THE AREA.
  
THE ATLANTIC OCEAN...
BROAD UPPER LEVEL ANTICYCLONIC WIND FLOW MOVES FROM FLORIDA AND 
THE BAHAMAS TOWARD THE AREA OF A CENTRAL ATLANTIC OCEAN TROUGH 
IN WATER VAPOR IMAGERY. A SURFACE TROUGH PASSES THROUGH 32N78W 
TO 30N80W TO THE FLORIDA EAST COAST NEAR 29N81W. RAINSHOWERS AND 
THUNDERSTORMS ARE WITHIN 60 NM ON EITHER SIDE OF 29N81W 30N77W 
BEYOND 32N74W. A CENTRAL ATLANTIC OCEAN MIDDLE LEVEL TO UPPER 
LEVEL TROUGH PASSES THROUGH 32N46W TO 26N49W. A COLD FRONT 
PASSES THROUGH 32N50W TO 28N60W TO 26N66W. A REMNANT CLOUD LINE 
CONTINUES FROM 26N66W TO 27N74W. ISOLATED MODERATE RAINSHOWERS 
AND POSSIBLE THUNDERSTORMS ARE TO THE NORTH OF 30N BETWEEN 45W 
AND 51W. PRECIPITATION IS POSSIBLE IN CLOUD CLUSTERS THAT ARE
TO THE NORTH OF 27N BETWEEN 50W AND 67W. SURFACE ANTICYCLONIC 
FLOW MOVES AROUND A 1017 MB HIGH PRESSURE CENTER THAT IS NEAR 
30N64W TO THE NORTHWEST OF THE FRONT. BROAD SURFACE 
ANTICYCLONIC FLOW COVERS THE ATLANTIC OCEAN BETWEEN THE 32N50W 
26N66W COLD FRONT AND THE COLD FRONT THAT RUNS FROM THE MADEIRA 
ARCHIPELAGO TO 23N29W. THIS ANTICYCLONIC FLOW MOVES AROUND
A 1019 MB HIGH PRESSURE CENTER THAT IS NEAR 26N45W. AN UPPER 
LEVEL TROUGH PASSES THROUGH 32N20W TO 20N25W 12N30W 6N40W.
THIS TROUGH SUPPORTS A COLD FRONT THAT PASSES THROUGH 32N16W
TO THE CANARY ISLANDS TO 23N29W. ANY PRECIPITATION APPEARS
TO BE TO THE NORTH OF 29N BETWEEN AFRICA AND 20W.

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

$$
MT