000
AXNT20 KNHC 052357
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL  
705 PM EST TUE JAN 05 2010

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 THE 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 2345 UTC.

...ITCZ...

THE ITCZ AXIS IS ANALYZED FROM THE NORTHERN COAST OF SIERRA 
LEONE NEAR 8N13W WESTWARD ALONG 4.5N20W 3N30W 2.5N40W TO 
NORTHEAST BRAZIL NEAR THE CITY OF MACAPA AT EQ50. ISOLATED WEAK 
TO MODERATE CONVECTION IS OCCURRING ALONG THE ITCZ FROM BETWEEN 
20W AND 43W.

...DISCUSSION...

GULF OF MEXICO...
THE GULF OF MEXICO REMAINS UNDER THE INFLUENCE OF A NORTH TO 
SOUTH ELONGATED SURFACE HIGH PRESSURE...WITH THE STRONGEST 
SUBSIDENCE OF AIR SITUATED ACROSS THE UNITED STATES ALONG THE 
95W LINE REACHING TO THE EASTERN TEXAS COAST. THIS SYSTEM IS 
BRINGING A DRY CONTINENTAL AIRMASS TO THE BASIN...SUPPRESSING 
DEEP CONVECTION IN THIS REGION. HENCE...SHIP AND BUOY 
OBSERVATIONS SHOW MOSTLY NORTHERLY WINDS 10 TO 20 KT WITH DEW 
POINTS RANGING MID 10S TO MID 50S OVER MOST OF THE BASIN. IN THE 
UPPER LEVELS OF THE ATMOSPHERE...LIGHT WEST TO NORTHWEST FLOW IS 
OVER THE ENTIRE REGION. A STREAM OF MID TO UPPER LEVEL MOISTURE 
IS BEEN TRANSPORTED FROM THE EASTERN TROPICAL PACIFIC INTO THE 
CENTRAL AND SOUTHERN GULF...SOUTH OF 26N. SURFACE PRESSURE 
GRADIENT IS EXPECTED TO SLOWLY LOOSEN OVER THE NEXT 24 
HOURS...AS THE SURFACE HIGH PRESSURE BECOMES WEAKER.

CARIBBEAN SEA...
IN THE UPPER LEVELS OF THE ATMOSPHERE ACROSS THE CARIBBEAN...DRY 
AIR ALOFT IS OVER MOST OF THE REGION...ESPECIALLY SOUTHWEST AND 
SOUTH CENTRAL. THIS IS SUPPRESSING DEEP CONVECTION OVER MOST OF 
THE REGION. NEVERTHELESS...THE SOUTHERN TIP OF AN UPPER LEVEL 
SHORTWAVE IS SWINGING ACROSS THE NORTHWEST BASIN...SUPPORTING A 
A SURFACE TROUGH THAT IS ANALYZED ACROSS THE HISPANIOLA INTO 
CENTRAL CARIBBEAN...ENTERING AS A SHEAR LINE FROM SW HAITI NEAR 
18N74W TO 15N80W TO 10N82W. SATELLITE IMAGERY SHOWS WEAK 
CONVECTION OCCURRING WITHING 100 NM ON EITHER SIDE OF THE 
BOUNDARY. TO THE EAST OF THE BOUNDARY...EASTERLY WINDS 5 TO 15 
KT ARE OBSERVED...WHILE TO THE WEST AND NORTHWEST OF THE 
BOUNDARY...NORTH-NORTHEAST WINDS 10 TO 20 KT ARE OBSERVED. LOOK 
FOR SIMILAR CONDITIONS ACROSS THE CARIBBEAN SEA OVER THE NEXT 24 
HOURS.


ATLANTIC OCEAN...
THE WEATHER ON THE WESTERN ATLANTIC REMAINS UNDER THE INFLUENCE 
OF A DEEP LAYERED TROUGH MOVING ACROSS THIS REGION. A BROAD AREA 
OF WEAK TO MODERATE CONVECTION IS OVER THE WESTERN ATLANTIC FROM 
22N TO 32N BETWEEN 55W AND 72W. A WEAKENING SURFACE TROUGH IS 
ANALYZED ALONG 27N60W 23N64W AND 20N70W. WEAK CONVECTION IS 
FOUND WITHIN 120 NM ON EITHER SIDE OF THE BOUNDARY. TO THE WEST 
OF THIS TROUGH...A COLD FRONT IS ANALYZED ALONG 32N62W 28N65W 
25N70W TO THE CENTRAL BAHAMAS. WEAK TO MODERATE CONVECTION IS 
WITHIN 120 NM EAST OF THIS FRONT. OVER THE NEXT 12 HOURS...WEST 
WINDS TO GALE FORCE ARE EXPECTED AHEAD THE FRONT. OTHERWISE...A 
1024 MB HIGH CENTERED OVER THE EASTERN ATLANTIC NEAR 27N33W 
DOMINATES THE WEATHER OVER THE REMAINDER OF THE 
ATLANTIC...BRINGING MOSTLY FAIR WEATHER TO THIS REGION.


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

$$

GARCIA