000 AXNT20 KNHC 241148 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 6N11W 1N24W 3N39W 1N50W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 60 NM EITHER SIDE OF LINE 4N26W 3N37W AND WITHIN 90 NM OF 3N42W AND 4N50W. ...DISCUSSION... GULF OF MEXICO... THE SOUTHERN EXTENSION OF AN SECONDARY UPPER TROUGH IS SWINGING SE ACROSS THE TEXAS COAST ATTM AND WILL REINFORCE THE ALREADY DRY AIR ALOFT WHICH IS NOTED NW OF A LINE ALONG 27N82W 24N90W 20N95W. 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 20N93W 26N82W. UPPER LEVEL MOISTURE...ORIGINATING FROM YESTERDAYS CONVECTION OVER CENTRAL AMERICA BETWEEN 89W AND 93W...IS STREAMING NE WITHIN 120 NM EITHER SIDE OF LINE FROM 18N92W TO BEYOND 26N81W...BUT APPEARS TO BE EVAPORATING W OF 88W. A SURFACE FRONT IS DISSIPATING ALONG LINE 29N81W 28N84W. 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 19N79W 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 WEAKENING MID LEVEL CYCLONE NEAR 13N62W. AN UPPER LEVEL WESTERLY JET IS AMPLIFYING N OVER CARIBBEAN S OF 16N 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 ACROSS THE CARIBBEAN SEAS N OF 12N EXCEPT BECOMING LOCALLY OVERCAST N OF 16N W OF 81W. ATLANTIC... AN UPPER ANTICYCLONE CENTERED OVER THE NW CARIBBEAN HAS A RIDGE EXTENDING NE TO BEYOND 32N58W. THE SOUTHERN EXTENSION OF AN UPPER TROUGH IS NOTED OVER THE EXTREME NW PORTION DISCUSSION AREA ACCOMPANIED BY DRY UPPER AIR W OF LINE 32N69W 29N81W. THE ASSOCIATED SURFACE COLD FRONT LIES ALONG 32N76W 30N76W BECOMING STATIONARY AND WEAKENING ACROSS THE FLORIDA COAST AT 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 32N62W. THIN BROKEN CIRRIFORM CLOUDS ARE NOTED ELSEWHERE UNDER THE UPPER RIDGE W OF LINE 32N37W 20N73W. THE CENTRAL SUB-TROPICAL ATLC IS DOMINATED ALOFT BY A WEAKENING UPPER TROUGH EXTENDING THROUGH CYCLONES FILLING AT 31N34W 24N38W 16N51W AND TO NEAR 13N63W. DRY UPPER AIR IS NOTED ROUGHLY WITHIN 360 NM EITHER SIDE OF LINE 26N38W 14N61W. THE UPPER LEVELS OF THE TROPICAL E ATLC IS DOMINATED BY AN UPPER RIDGE ALONG 8N 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 14N38W THEN BEGINS EVAPORATING BUT CONTINUES E ACROSS AFRICA BEYOND 24N12W. AT THE LOW LEVELS A HIGH PRES IS AT 32N38W 1027 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