000
AXNT20 KNHC 240550
TWDAT 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
105 AM EST SUN FEB 24 2008

TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL 
AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN 
SECTIONS OF SOUTH AMERICA...AND THE 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0545 UTC.

...ITCZ...
THE ITCZ AXIS IS CENTERED ALONG 6N12W 2S44W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION NOTED WITHIN 60 NM EITHER SIDE OF 
LINE 4N25W 3N35W AND WITHIN 60 NM OF 3.5N41W.

...DISCUSSION...
GULF OF MEXICO...
THE SOUTHERN EXTENSION OF AN SECONDARY UPPER TROUGH IS SWINGING 
SE TOWARDS THE TEXAS COAST TO REINFORCE THE ALREADY DRY AIR 
ALOFT WHICH IS NOTED W OF A LINE FROM 26N87W TO 21N97W. AN UPPER 
ANTICYCLONE HAS RE-ESTABLISHED ITSELF OVER THE NW CARIBBEAN. ITS 
ENVELOPE OF ANTICYCLONIC FLOW CRESTS OVER THE SE GULF OF MEXICO 
ALONG POINTS 20N96W 27N82W. UPPER LEVEL MOISTURE...ORIGINATING 
FROM FORMER CONVECTION OVER CENTRAL AMERICA BETWEEN 89W AND 
93W...IS STREAMING NE WITHIN 120 NM EITHER SIDE OF LINE 18N92W 
26N80W. A SURFACE FRONT IS DISSIPATING ALONG LINE 29N81W 27N87W.
LOCALLY BROKEN LOW CLOUDS ARE OBSERVED ALONG THE BOUNDARY WITH 
ASSOCIATED PRECIPITATION ONLY LIGHT RAIN AT BEST. SE OF THE 
FRONT...THE ATLC SUBTROPICAL RIDGE EXTENDS W OVER THE STRAITS OF 
FLORIDA TO NEAR 24N84W.

CARIBBEAN...
AN UPPER ANTICYCLONE HAS RE-ESTABLISHED ITSELF OVER THE NW 
CARIBBEAN NEAR 19N78W WITH ITS ANTICYCLONIC ENVELOPE STILL 
DOMINATING THE CARIBBEAN N OF 14N W OF 65W. THE WESTERN 
EXTENSION OF A CENTRAL ATLC UPPER TROUGH STILL EXTENDS OVER THE 
EASTERN CARIBBEAN TO A WEAK CYCLONE NEAR 13N62W...BUT THIS 
APPEARS TO MOSTLY MID LEVEL AS AN UPPER LEVEL WESTERLY JET IS 
BEGINNING TO SHIFT N OVER THE SOUTHERN CARIBBEAN...GENERALLY S 
OF 14N...ACCOMPANIED BY THIN BROKEN CIRRIFORM CLOUDS. AT THE LOW 
LEVELS THE ATLC SUBTROPICAL RIDGE IS SUPPORTING BRISK EASTERLY 
FLOW. LOCALLY BROKEN LOW CLOUDS WITH EMBEDDED SHOWERS ARE NOTED 
N OF 16N W OF 80W.

ATLANTIC...
AN UPPER ANTICYCLONE CENTERED OVER THE NW CARIBBEAN HAS A 
RIDGE EXTENDING NE TO BEYOND 32N60W. THE SOUTHERN EXTENSION OF 
AN UPPER TROUGH IS NOTED OVER THE EXTREME NW PORTION DISCUSSION 
AREA ALONG 32N77W 29N31W ACCOMPANIED BY DRY UPPER AIR. THE 
ASSOCIATED SURFACE COLD FRONT LIES ALONG 32N79W 29N81W. A 
MOISTURE PLUME IS NOTED SE OF THIS TROUGH ALONG THE RIDGE 
CREST...ROUGHLY WITHIN 120 NM EITHER SIDE OF LINE FROM 27N80W TO 
BEYOND 32N64W. THIN BROKEN CIRRIFORM CLOUDS ARE NOTED ELSEWHERE 
UNDER THE UPPER RIDGE W OF LINE 32N35W 21N70W. THE CENTRAL 
SUB-TROPICAL ATLC IS DOMINATED ALOFT BY A WEAKENING UPPER TROUGH 
EXTENDING THROUGH CYCLONES FILLING AT 33N34W 25N39W 17N50W AND 
13N63W. DRY UPPER AIR IS NOTED ROUGHLY WITHIN 360 NM EITHER SIDE 
OF LINE 26N38W 14N61W.

THE TROPICAL E ATLC IS DOMINATED ALOFT BY AN UPPER RIDGE ALONG 
8N TO THE E OF 45W. UPPER DIFFLUENCE ALONG THIS RIDGE AXIS IS 
ENHANCING CONVECTION N OF THE ITCZ AXIS...DESCRIBED ABOVE. A 300 
NM WIDE MOISTURE PLUME...MOSTLY ORIGINATING FROM CONVECTION OVER 
S AMERICA...STREAMS NE ALONG AXIS 3N52W 13N38W THEN BEGINS 
EVAPORATING BUT CONTINUES BEYOND 24N7W. AT THE LOW LEVELS A HIGH 
PRES IS AT 33N35W 1029 MB WITH A RIDGE SW THROUGH THE STRAITS OF 
FLORIDA CRESTING OVER THE SE GULF OF MEXICO. LOCALLY BROKEN 
STRATOCUMULUS IS MOVING ANTICYCLONICALLY SW ACROSS THE WATERS SE 
OF THIS RIDGE.

$$
NELSON