000
AXNT20 KNHC 101732
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT TUE MAR 10 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.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 5N7W 1N20W CROSSING THE EQUATOR 
NEAR 28N THEN ALONG 2S35W AND INTO NE BRAZIL NEAR 3S45W. 
SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 60 NM EITHER 
SIDE OF THE AXIS BETWEEN THE AFRICAN COAST AND 17W.

...DISCUSSION...

GULF OF MEXICO...
DEEP LAYER RIDGING CONTINUES TO DOMINATE THE GULF THIS 
AFTERNOON. A 1022 MB SFC HIGH IN APALACHICOLA BAY IS PROVIDING 
LIGHT WINDS OVER THE NE GULF. SOUTHERLY RETURN FLOW OF 15-20 KT 
ON THE WESTERN PERIPHERY OF THE SFC RIDGE COVERS THE REMAINDER 
OF THE REGION. ALOFT...STRONG SOUTHWESTERLY FLOW IS ADVECTING 
MOISTURE ACROSS MEXICO AND INTO THE EASTERN CONUS... 
HOWEVER...LITTLE OF THIS MOISTURE IS MAKING ITS WAY INTO THE 
GULF AS DRY AIR IS PRESENT ACROSS THE ENTIRE REGION AT ALL 
LEVELS. EXPECT LITTLE CHANGE OVER THE NEXT FEW DAYS AS THE DEEP 
LAYER RIDGE REMAINS IN PLACE.

CARIBBEAN SEA...
THE PRESSURE GRADIENT BETWEEN A 1023 MB HIGH OVER THE BAHAMAS 
AND LOWER PRESSURE OVER SOUTH AMERICA IS GENERATING FRESH TO 
STRONG TRADE WINDS ACROSS THE CARIBBEAN. THE TRADE WIND FLOW IS 
EXPECTED TO DIMINISH LATER IN THE WEEK AS THE HIGH PRESSURE TO 
THE NORTH WEAKENS. LOW-LEVEL CLOUDS AND ISOLATED SHOWERS ARE 
RIDING THE TRADE WIND FLOW ACROSS THE EASTERN CARIBBEAN...MAINLY 
E OF 72W. THIS CONVECTION IS SHALLOW IN NATURE AS STRONG 
SUBSIDENCE AND DRY AIR COVER THE REGION AT THE BASE OF AN UPPER 
TROUGH THAT EXTENDS ACROSS THE WINDWARD PASSAGE TO NEAR 14N80W.
LITTLE CHANGE IN THE LARGE SCALE WEATHER PATTERN IS ANTICIPATED 
OVER THE NEXT DAY OR SO.

ATLANTIC OCEAN...
THE PREMIER WEATHER FEATURE IN THE DISCUSSION AREA CONTINUES TO 
BE THE DEEP-LAYER LOW SPINNING IN THE CENTRAL ATLC. THE 1001 MB 
SFC LOW IS CENTERED NEAR 31N41W. A SFC TROUGH EXTENDS AHEAD OF 
THE LOW CENTER FROM 30N37W ALONG 25N36W TO 11N47W. MULTI-LEVEL 
CLOUDS AND SCATTERED SHOWERS ARE WITHIN 50 NM OF THIS BOUNDARY. 
A SECONDARY TROUGH EXTENDS FROM THE LOW CENTER ALONG 28N39W TO 
24N41W. CLOUDINESS AND EMBEDDED SHOWERS ARE OBSERVED BETWEEN THE 
TWO TROUGHS. SHIP OBSERVATIONS AS WELL AS QUIKSCAT INDICATE GALE 
FORCE WINDS ARE STILL PRESENT IN THE EASTERN SEMICIRCLE OF THE 
LOW PRESSURE SYSTEM. AS SUCH...A GALE WARNING REMAINS IN EFFECT 
WITHIN 240 NM E OF THE LOW CENTER. IN THE W ATLC...A 1023 MB SFC 
HIGH OVER THE BAHAMAS CONTINUES TO WEAKEN AS LOW PRESSURE 
APPROACHES FROM THE NORTH. A 998 MB SFC LOW CENTERED NEAR 36N60W 
EXTENDS A COLD FRONT THAT CLIPS THE NRN PORTION OF THE 
DISCUSSION AREA ALONG 32N61W 30N64W 30N70W TO 32N78W. WINDS 
CONTINUE TO INCREASE AS THE LOW PRESSURE MOVES SOUTHEASTWARD AND 
A GALE WARNING IS EXPECTED WITHIN 24 HOURS N OF 28N BETWEEN 
57W-62W. A SFC RIDGE EXTENDS ACROSS THE AZORES TO THE CAPE VERDE 
ISLANDS MAINTAINING TRANQUIL CONDITIONS ACROSS THE EAST ATLC.

$$
WADDINGTON