000
AXNT20 KNHC 201147
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
705 AM EST TUE JAN 20 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 1045 UTC.

...THE ITCZ...
FROM THE COAST OF LIBERIA ALONG 10W TO THE EQUATOR ALONG 27W...
ALONG THE EQUATOR TO 32W...INTO NORTHEASTERN BRAZIL NEAR 3S45W. 
NUMEROUS STRONG SHOWERS AND THUNDERSTORMS ARE ALONG THE COAST OF 
SOUTH AMERICA FROM BRAZIL NEAR 48W TO THE BRAZIL/FRENCH GUIANA 
BORDER SOUTH OF 4N. SCATTERED STRONG SHOWERS AND THUNDERSTORMS 
ARE SOUTH OF 5N BETWEEN 8W AND 17W...FROM THE EQUATOR TO 1N
BETWEEN 22W AND 23W...FROM THE EQUATOR TO 2N BETWEEN 33W AND 
35W...AND FROM THE EQUATOR TO 1N BETWEEN 38W AND 43W.
 
...DISCUSSION...

THE GULF OF MEXICO AND THE ATLANTIC OCEAN WEST OF 70W...
A DEEP-LAYER TROUGH HAS DUG INTO THE GULF OF MEXICO. CYCLONIC 
FLOW FROM THIS TROUGH COVERS THE ENTIRE AREA. THIS TROUGH
SUPPORTS ONE COLD FRONT THAT PASSES FROM THE ATLANTIC OCEAN NEAR 
32N70W TO ANDROS ISLAND TO WESTERN CUBA...DISSIPATING ACROSS
THE YUCATAN PENINSULA INTO THE SOUTHWESTERN CORNER OF THE GULF 
OF MEXICO. A SECOND COLD FRONT PASSES THROUGH SOUTH FLORIDA
ABOUT 60 NM NORTH OF LAKE OKEECHOBEE INTO THE CENTRAL GULF 
WATERS. EXPECT COMPARATIVELY MUCH COLDER TEMPERATURES IN THE 
U.S.A. NORTHERN GULF COAST AREAS AND IN FLORIDA FOR AT LEAST
THE NEXT 48 HOURS OR SO. GALE WIND CONDITIONS ARE FORECAST IN 
THE ATLANTIC OCEAN NORTH OF 27N BETWEEN 65W AND 78W FOR THE
NEXT 24 HOURS OR SO.

THE CARIBBEAN SEA...
UPPER LEVEL SOUTHWESTERLY WIND FLOW FROM THE SOUTHWESTERN CORNER 
OF THE GULF OF MEXICO AND THE YUCATAN PENINSULA OF MEXICO MERGES
WITH THE CYCLONIC FLOW AROUND THE BASE OF THE DEEP LAYER TROUGH
IN THE SOUTHEASTERN CORNER OF THE GULF OF MEXICO. COMPLETELY 
SEPARATE UPPER LEVEL ANTICYCLONIC FLOW MOVES FROM COLOMBIA AND 
PANAMA TOWARD CUBA. A SURFACE TROUGH PASSES FROM THE WINDWARD 
PASSAGE TO THE JAMAICA CHANNEL TOWARD EASTERN PANAMA. THIS 
TROUGH IS DENOTED BY A DEFINITE CLOUD LINE. SHOWERS ARE POSSIBLE 
IN THE CLOUD LINE WITH THE TROUGH. THIS TROUGH IS FORECAST TO 
CONTINUE TO DRIFT WESTWARD AND DISSIPATE ALONG 80W DURING THE 
LATE NIGHT AND EARLY MORNING HOURS OF TODAY. THE NEXT COLD FRONT 
WILL MOVE THROUGH THE YUCATAN CHANNEL LATE ON TONIGHT AND REACH 
FROM HISPANIOLA TO NICARAGUA LATE ON WEDNESDAY. NORTHWESTERLY 
WINDS OF 20 KT WILL FOLLOW THE FRONT.

THE REST OF THE ATLANTIC OCEAN EAST OF 70W...
A SURFACE TROUGH THAT IS LOSING ITS UPPER LEVEL SUPPORT AS IT 
HAD EARLIER...PASSES THROUGH 31N60W TO 27N66W TO THE TURKS 
ISLANDS OF THE SOUTHERN BAHAMAS. POSSIBLE SHOWERS ARE WITHIN
30 NM ON EITHER SIDE OF THE TROUGH. AN UPPER LEVEL RIDGE IS
ALONG 40W FROM 10N TO BEYOND 32N. BROAD MIDDLE LEVEL CYCLONIC
FLOW COVERS THE AREA FROM 10N TO 27N BETWEEN 30W AND 53W.
A SECOND SMALLER UPPER LEVEL RIDGE IS ALONG 34W/35W SOUTH OF
19N. A MIDDLE TO UPPER LEVEL TROUGH BROAD SURFACE ANTICYCLONIC
WIND FLOW COVERS THE AREA NORTH OF 10N BETWEEN AFRICA AND 60W.

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