000 AXNT20 KNHC 180536 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU MAR 18 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0345 UTC... ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N11W 3N21W CROSSING THE EQUATOR NEAR 37W AND INTO NE BRAZIL NEAR 2S45W. CLUSTERS OF ISOLATED MODERATE CONVECTION ARE WITHIN 75 NM OF LINE FROM 5N17W 2N30W 2N40W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER LOW COVERS THE SE US AND THE N GULF WITH SHORTWAVE UPPER TROUGHS ROTATING AROUND A CENTRAL POINT OVER TENNESSEE. THE EASTERN MOST SHORTWAVE IS SUPPORTING A 1010 MB LOW OFF THE FLORIDA COAST IN THE W ATLC AND A SURFACE TROUGH EXTENDING ACROSS FLORIDA NEAR LAKE OKEECHOBEE AND NAPLES TO 24N84W WITH A SECOND SURFACE TROUGH EXTENDING NW THROUGH TALLAHASSEE...SW GEORGIA AND N ALABAMA. A SECOND SHORTWAVE UPPER TROUGH IS MOVING S INTO THE NW GULF OVER LOUISIANA AND E TEXAS SUPPORTING A 1016 MB LOW OVER SE LOUISIANA AND A SURFACE TROUGH EXTENDING NW TO SW ARKANSAS. ISOLATED SHOWERS ARE N OF 23N E OF 87W AND N OF 27N BETWEEN 87W-92W. NEAR ZONAL WESTERN UPPER FLOW THAT COVERS THE REMAINDER OF THE GULF IS ENHANCING A JETSTREAM WITH WINDS OF 90 TO 125 KT N OF 24N W OF 90W AND FROM 20N-29N E OF 90W. SOUTHERLY RETURN FLOW WILL SET UP OVER THE NW GULF BY THU NIGHT SPREADING E ACROSS THE GULF BY SAT MORNING IN ADVANCE OF NEXT COLD FRONT MOVING OFF THE TEXAS COAST SAT NIGHT. CARIBBEAN SEA... THE NORTHERLY SURFACE FLOW FROM THE GULF OF MEXICO EXTENDS S OVER THE W CARIBBEAN AND COMBINED WITH THE EASTERLY TRADE WINDS ACROSS THE REMAINDER OF THE CARIBBEAN IS GENERATING DENSE LOW LEVEL CLOUDS AND SCATTERED SHOWERS S OF 20N W OF 82W WITH ISOLATED SHOWERS DOTTING THE REMAINDER OF THE W CARIBBEAN W OF 80W. THE REMNANTS OF A STATIONARY FRONT EXTEND OVER THE VIRGIN ISLANDS TO ALONG THE S COAST OF THE DOMINICAN REPUBLIC WITH A SURFACE TROUGH EXTENDING FROM NEAR THE FRONT OVER THE VIRGIN ISLANDS SW TO 14N72W. ISOLATED SHOWERS ARE WITHIN 30 NM EITHER SIDE FOR THE FRONT/TROUGH. BROAD UPPER RIDGE DOMINATES THE CARIBBEAN ANCHORED OVER E VENEZUELA AND EXTENDS INTO THE W ATLC AND OVER THE TROPICAL ATLC TO 45W. THIS UPPER FLOW IS DRAWING TROPICAL MOISTURE N OVER THE S CARIBBEAN AND IS PRODUCING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 13N TO INLAND OVER SOUTH AMERICA BETWEEN 68W-77W. ATLANTIC OCEAN... BROAD UPPER LOW COVERS THE SE US AND THE N GULF OF MEXICO INTO THE W ATLC WITH SHORTWAVE UPPER TROUGHS ROTATING AROUND A CENTRAL POINT OVER TENNESSEE. THE EASTERN MOST SHORTWAVE IS ALONG THE COAST OF GEORGIA TO SOUTH CAROLINA SUPPORTING A 1010 MB LOW OFF THE FLORIDA COAST NEAR DAYTONA BEACH AND A SURFACE TROUGH EXTENDING SW ACROSS FLORIDA NEAR LAKE OKEECHOBEE CONTINUING INTO THE GULF OF MEXICO. A SECOND SURFACE TROUGH EXTENDS W TO OVER DAYTONA BEACH THEN NW OVER THE SE US WHILE A THIRD SURFACE TROUGH EXTENDS N FROM THE LOW TO BEYOND 32N79W. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE FROM 28N-34N BETWEEN 75W-79W WITH ISOLATED SHOWERS COVERING THE REMAINDER OF THE AREA W OF 70W. A WEAK 1016 MB HIGH IS TO THE NE OF THE CENTRAL BAHAMAS NEAR 26N70W AS THE BROAD UPPER RIDGE THAT DOMINATES THE CARIBBEAN EXTENDS AN AXIS N ACROSS PUERTO RICO TO NEAR 32N65W. AN UPPER TROUGH IS OVER THE CENTRAL ATLC N OF 28N BETWEEN 33W-55W SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N35W EXTENDING SW ALONG 24N47W TO 20N57W WHERE IT BECOMES STATIONARY TO OVER THE VIRGIN ISLANDS AND ALONG THE S COAST OF THE DOMINICAN REPUBLIC. ISOLATED SHOWERS ARE WITHIN 60 NM SE OF THE COLD FRONT AND WITHIN 30 NM EITHER SIDE FOR THE STATIONARY FRONT. AN UPPER RIDGE AXIS EXTENDS FROM THE BROAD UPPER RIDGE OVER THE TROPICAL ATLC THROUGH 16N45W TO BEYOND 32N21W PROVIDING DIFFLUENCE ALOFT TO GENERATE ISOLATED SHOWERS WITHIN 150 NM OF LINE FROM 26N38W TO BEYOND 32N29W. A SURFACE RIDGE DOMINATES THE E ATLC EXTENDING THROUGH 32N14W TO A 1021 MB HIGH JUST W OF THE CANARY ISLANDS NEAR 27N21W TO A 1018 MB HIGH NEAR 19N35W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ WALLACE