000 AXNT20 KNHC 200547 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN MAR 20 2011 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...GULF OF MEXICO...CARIBBEAN SEA...NORTHERN SECTION 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ... THE ITCZ AXIS EXTENDS ALONG 05N09W TO THE EQUATOR NEAR 18W THEN ALONG 01S TO 28W AND INTO NE BRAZIL NEAR 05S37W. SCATTERED MODERATE CONVECTION IS FROM 03N-06N BETWEEN 04W-17W. ISOLATED MODERATE CONVECTION IS FROM THE EQUATOR TO 03N BETWEEN 28W-34W. ...DISCUSSION... GULF OF MEXICO... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER CENTRAL MEXICO NEAR 18N101W THAT EXTENDS A RIDGE AXIS NE ACROSS THE WESTERN GULF AND PORTIONS OF THE SE CONUS. MOSTLY SUBSIDENT NORTHWESTERLY FLOW ALOFT IS NOTED ON WATER VAPOR IMAGERY WHICH IS SUPPORTIVE OF A 1024 MB SURFACE HIGH CENTERED OVER THE NE GULF NEAR 27N84W. SHIP AND BUOY OBSERVATIONS INDICATE EAST TO SOUTHEAST WINDS IN THE RANGE OF 10 TO 20 KT ARE ACROSS THE GULF CURRENTLY AND THIS WIND REGIME IS FORECAST TO PERSIST THROUGH EARLY WEDNESDAY AS THE HIGH REMAINS STATIONARY WITH AXIS ALONG 28N. SKIES ARE EXPECTED TO REMAIN CLEAR THROUGH THE OVERNIGHT HOURS WITH AREAS OF PATCHY TO DENSE FOG POSSIBLE ALONG THE IMMEDIATE GULF COAST WATERS W OF 85W. CARIBBEAN SEA... MOST OF THE CARIBBEAN SEA BASIN IS UNDER THE INFLUENCE OF A BROAD UPPER LEVEL RIDGE CENTERED OVER THE TROPICAL ATLC WITH ASSOCIATED DRY AIR AND SUBSIDENCE. THIS OVERALL PATTERN IS LIMITING ANY SIGNIFICANT DEEP CONVECTION...WITH ONLY A FEW AREAS OF TRADEWIND SHOWERS NOTED ON SATELLITE IMAGERY. OF NOTE...AN AREA OF ISOLATED SHOWERS REMAINS FOCUSED IN THE VICINITY OF A SURFACE TROUGH ANALYZED FROM 12N61W TO 15N59W EAST OF THE LESSER ANTILLES. THE ACTIVITY COVERS THE AREA S OF 17N BETWEEN 58W-65W. ANOTHER AREA OF ISOLATED SHOWERS IS OCCURRING FROM 14N-18N BETWEEN 81W-90W...INCLUDING INTERIOR PORTIONS OF HONDURAS... BELIZE...AND GUATEMALA. ALSO...LOW-LEVEL SPEED CONVERGENCE OF THE TRADES OVER THE SW CARIBBEAN IS GENERATING ISOLATED SHOWERS S OF 12N W OF 78W ACROSS THE COSTA RICA AND WESTERN PANAMA COAST. ATLANTIC OCEAN... SURFACE HIGH PRESSURE LOCATED OVER THE FLORIDA PENINSULA EXTENDS EASTWARD OVER THE SW NORTH ATLC WATERS MAINTAINING OVERALL FAIR CONDITIONS FOR THE OVERNIGHT PERIOD W OF 60W. A WEAKENING COLD FRONT IS ANALYZED INTO THE DISCUSSION AREA NEAR 32N70W TO 32N79W THEN INLAND NEAR BEAUFORT SOUTH CAROLINA. VERY LITTLE MIDDLE TO UPPER LEVEL MOISTURE IS ASSOCIATED WITH THE FRONT...HOWEVER... POSSIBLE ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE FRONT AS IT CONTINUES TO MOVE S-SE. AN AREA OF STRONGER NE WINDS IN THE RANGE OF 20 TO 25 KT RESIDE NORTH OF THE FRONT AS DEPICTED BY A RECENT 20/0144 UTC ASCAT PASS. FARTHER EAST...AN UPPER LEVEL SHORTWAVE TROUGH IS ALONG 50W AND SUPPORTS A 1014 MB LOW CENTERED NEAR 27N51W. A SURFACE TROUGH EXTENDS S-SW FROM THE LOW ALONG 24N50W TO 19N53W WITH ISOLATED SHOWERS AND POSSIBLE TSTMS FROM 18N-27N BETWEEN 44W-54W. A WARM FRONT ALSO EXTENDS EAST FROM THE LOW TO 27N45W. LOW-LEVEL CONVERGENCE GENERATED FROM THE FRONT ALONG WITH AMPLE MIDDLE TO UPPER LEVEL DIFFLUENCE IS GENERATING ISOLATED SHOWERS AND TSTMS FROM 27N-31N BETWEEN 43W-53W. A RECENT ASCAT PASS FROM AROUND 20/0000 UTC DEPICTED THE LOW CIRCULATION WITH STRONG E TO SE WINDS IN THE RANGE OF 20 TO 30 KT COVERING THE AREA FROM 22N-31N BETWEEN 43W-52W. THE REMAINDER OF THE EASTERN ATLC IS DOMINATED BY A SURFACE RIDGE ANCHORED ON A 1025 MB HIGH CENTERED NEAR 36N38W SUPPORTING OVERALL FAIR WEATHER CONDITIONS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN