000
AXNT20 KNHC 081741
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 PM EST SUN FEB 08 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1715 UTC.

...THE ITCZ...

ITCZ IS CENTERED ALONG 6N10W 2N20W THEN ALONG THE EQUATOR 
BETWEEN 30W AND 40W...AND INTO NE BRAZIL NEAR 2S47W. SCATTERED 
MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 80 NM S OF AXIS 
BETWEEN 9W-14W. ISOLATED MODERATE CONVECTION IS WITHIN 100 NM N 
OF AXIS AND EAST OF 15W TO THE COAST OF AFRICA. ELSEWHERE... 
SCATTERED SHOWERS ARE ALONG THE ITCZ AXIS.     
 
...DISCUSSION...

GULF OF MEXICO...
A 1033 MB SURFACE HIGH PRESSURE CENTERED OVER SOUTH GEORGIA  
NEAR 31N83W REMAINS IN CONTROL OF THE WEATHER PATTERN ACROSS THE 
ENTIRE GULF PRODUCING MOSTLY FAIR WEATHER AND SE-S RETURN FLOW. 
THESE WINDS ARE EXPECTED TO INCREASE TO 20-25 KT TONIGHT AS THE 
NEXT LOW PRESSURE SYSTEM DEVELOPS OVER THE SRN PLAIN STATES. 
SCATTERED COLD AIR STRATOCUMULUS CLOUDS ARE STILL NOTED OVER THE 
GULF MOVING MAINLY N UNDER THE PREDOMINANT WIND FLOW. ALOFT...A 
MID TO UPPER LEVEL RIDGE DOMINATES MUCH OF THE GULF WATERS WHILE 
A SHORT-WAVE TROUGH IS OVER WESTERN CUBA. THE SFC HIGH...WHICH 
ALSO DOMINATES THE SE CONUS...WILL SLIDE E OF AREA THROUGH TUE 
IN ADVANCE OF THE NEXT COLD FRONT EXPECTED TO MOVE OFF THE TEXAS 
COAST EARLY WED.

CARIBBEAN SEA...
A TIGHT SURFACE GRADIENT BETWEEN THE SURFACE HIGH OVER S GEORGIA 
AND LOWER PRES OVER S AMERICA IS PRODUCING FRESH TO STRONG TRADE 
WINDS OVER THE CENTRAL AND W CARIBBEAN. AN EARLIER QSCAT PASS 
SHOWED NE WINDS OF UP TO 30 KT JUST OFFSHORE THE COAST OF 
COLOMBIA. THIS WEATHER PATTERN IS EXPECTED TO PERSIST DURING THE 
NEXT 24 HOURS. THE NE-E WINDS ASSOCIATED WITH THE SFC HIGH ARE 
TRANSPORTING PATCHES OF MOISTURE WITH EMBEDDED SHOWERS ACROSS 
THE LEEWARD ISLANDS...THE UK/US VIRGIN ISLANDS...PUERTO 
RICO...HISPANIOLA AND THE EASTERNMOST PROVINCES OF CUBA. 
ADDITIONAL CONCENTRATED POCKETS OF MOISTURE WITH MAINLY LIGHT 
RAIN ARE ALSO AFFECTING MUCH OF CENTRAL AMERICA LIKELY RELATED 
TO THE LOW-LEVEL WIND/SPEED CONVERGENCE. AS PREVIOUSLY 
MENTIONED...THE SPEED CONVERGENCE OVER THIS REGION IS A RESULT 
OF THE FRESH TO STRONG TRADES OVER THE CENTRAL AND W CARIBBEAN. 
ALOFT... AN UPPER LEVEL HIGH IS CENTERED OVER E VENEZUELA NEAR 
7N62W. SW TO W UPPER LEVEL FLOW COVERS THE ENTIRE CARIBBEAN WITH 
STRONG SUBSIDENCE. 

ATLANTIC OCEAN...
AN DEEP LAYERED TROUGH OVER THE E-CENTRAL ATLC N OF 28N SUPPORTS 
A COLD FRONT THAT ENTERS THE DISCUSSION AREA NEAR 31N38W THEN 
CONTINUES SW ALONG 26N46W 20N57W. LOW-LEVEL CONVERGENCE IS 
SUPPORTING SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF THE 
FRONTAL BOUNDARY PARTICULARLY N OF 26N. A HIGH PRES SYSTEM IS IN 
THE WAKE OF THE FRONT WITH THE MAIN CENTER OF 1033 MB OVER SOUTH 
GEORGIA. NE WINDS OF 20 TO 25 KT AROUND THE SOUTHERN PERIPHERY 
OF THIS HIGH ARE ADVECTING FRAGMENTS OF LOW/MID CLOUDS WITH 
EMBEDDED LIGHT SHOWERS ACROSS THE BAHAMAS AND THE GREATER 
ANTILLES. E OF THE FRONT...THERE IS A SFC TROUGH EXTENDING FROM 
26N42W TO 18N44W. AN ASCAT PASS FROM AROUND 1300 UTC INDICATED 
SOME WIND SHIFT ASSOCIATED WITH THIS TROUGH WHILE THE TPW 
PRODUCT FROM UW-CIMSS SHOWS A SURGE OF MOISTURE IN THAT AREA. 
THE REMAINDER OF ATLC IS UNDER THE INFLUENCE OF A 1027 MB SFC 
HIGH LOCATED WEST OF THE MADEIRA ISLANDS NEAR 33N19W. THIS 
FEATURE WILL CONTINUE TO MOVE EWD. ALOFT...A DEEP LAYERED UPPER 
RIDGING IS ACROSS MUCH OF THE CENTRAL AND EASTERN ATLC EXTENDING 
FROM THE ABOVE MENTIONED UPPER-LEVEL HIGH LOCATED OVER E 
VENEZUELA. AN ELONGATED TROUGH LIES SE OF THE RIDGE CROSSING 
BETWEEN THE CANARY AND CAPE VERDE ISLANDS TO NEAR 20N28W THEN 
CONTINUING SW INTO THE DEEP TROPICS TO NEAR THE NE COAST OF 
BRAZIL. AN AREA OF MODERATE CONVECTION IS ALONG THE COASTLINES 
OF FRENCH GUIANA AND SURINAME ENHANCED BY UPPER DIFFLUENCE.

$$
GR