000 AXNT20 KNHC 090002 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT MON APR 08 2013 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2300 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF SIERRA LEONE NEAR 08N13W TO 02N23W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 02N23W TO THE EQUATOR ALONG 30N TO THE COAST OF BRAZIL NEAR 03S39W. SCATTERED MODERATE CONVECTION PERSISTS WITHIN 210 NM OF THE MONSOON TROUGH AXIS BETWEEN 13W AND 17W AND WITHIN 120 NM N OF THE ITCZ BETWEEN 30W AND 35W. ...DISCUSSION... GULF OF MEXICO... A MID LEVEL SHORT WAVE TROUGH ROTATING AROUND THE BASE OF THE MAIN TROUGH CENTERED OVER THE GREAT BASIN THROUGH TEXAS IS SUPPORTING A BROAD AREA OF SHOWERS OVER THE FAR NW GULF OF MEXICO THIS AFTERNOON. WIDESPREAD MULTI-LEVEL CLOUD COVER IS NOTED N OF 25N W OF 90W. COASTAL RADAR RETURNS HINT THIS SHOWER ACTIVITY IS MAINLY FROM SW LOUISIANA TO OFF THE NORTH COAST OF THE MEXICAN STATE OF TAMAULIPAS. ELSEWHERE GENERALLY STABLE CONDITIONS CONTINUE UNDER DOMINANCE OF HIGH PRES OVER THE GULF. A SURFACE RIDGE EXTENDS FROM THE WESTERN ATLC ACROSS THE NORTHERN GULF TO THE TEXAS COAST. BUOY...SHIP AND OSCAT DATA INDICATE MODERATE TO FRESH SE FLOW S OF THE RIDGE OVER MUCH OF THE SOUTHERN GULF MAINLY S OF 25N...AND LIGHT TO MODERATE FLOW OVER THE NORTHERN GULF WATERS. LOOKING AHEAD...SOUTHERLY WINDS OVER THE NW GULF WILL INCREASE THROUGH MIDWEEK...AHEAD OF A COLD FRONT THAT WILL REACH THE NW GULF BY LATE WED. THE FRONT IS EXPECTED TO MOVE SE AND STALL FROM FORT MYERS FLORIDA TO THE W CENTRAL GULF ON SAT. CARIBBEAN SEA... A 1025 MB HIGH PRES AREA CENTERED W OF BERMUDA NEAR 33N70W CONTINUES TO BE THE MAIN INFLUENCE ON THE WEATHER OVER THE CARIBBEAN...MAINTAINING GENERALLY MODERATE TO FRESH TRADE WIND FLOW OVER MUCH OF THE EASTERN CARIBBEAN BASIN...AND LIGHT TO MODERATE E TO SE WINDS OVER THE WESTERN CARIBBEAN. AN ASCAT PASS FROM AROUND 17 UTC SHOWED NE TO E WINDS NEAR 25 KT OFF THE COAST OF COLOMBIA. BOUNDARY LAYER TURBULENCE ASSOCIATED WITH THE FRESH TRADES IS SUPPORTING A FEW DOWNSTREAM SHOWERS OVER THE WATERS JUST W OF THE LEEWARD AND WINDWARD ISLANDS...AND W OF HISPANIOLA. AFTERNOON THUNDERSTORMS OVER THE HIGHER TERRAIN OF HISPANIOLA AND EASTERN CUBA HAVE STARTED TO DIMINISH. MID AND UPPER LEVELS REMAIN DRY WITH WESTERLY ZONAL FLOW...MAINTAINING STABLE AND GENERALLY CLOUD FREE AREAS ELSEWHERE ACROSS THE CARIBBEAN. RIDGING WILL REMAIN IN EFFECT THROUGH THE REMAINDER OF THE WEEK...WITH LITTLE CHANGE EXPECTED IN PREVAILING CONDITIONS. ATLANTIC OCEAN S OF 32N... DEEP LAYER RIDGING CONTINUES TO COVER THE ATLC WATERS W OF 50W. A MID/UPPER RIDGE IS BUILDING E AND COMING INTO PHASE WITH A 1025 MB SURFACE HIGH CENTERED W OF BERMUDA NEAR 33N70W. MODERATE E TRADES ARE NOTED IN BUOY AND SCATTEROMETER DATA W OF 50W N OF 22N...WITH MODERATE TO FRESH TRADES NOTED S OF 22N. HIGH MOISTURE VALUES OVER THE GULF STREAM ARE CONTRIBUTING TO A FEW LOW TOPPED SHOWERS OFF THE COAST OF E CENTRAL FLORIDA...ALTHOUGH THIS IS NOT MAKING IT INLAND. JUDGING BY VISIBLE SATELLITE IMAGERY FROM THIS AFTERNOON...ADDITIONAL SHOWERS MAY BE ACTIVE DUE TO TRADE WIND CONVERGENCE FROM 20N TO 25N BETWEEN 50W AND 70W. THE RIDGING IS FOLLOWING BEHIND A LOW AMPLITUDE SHORT WAVE TROUGH OVER THE N CENTRAL ATLC...WHICH HAD BEEN PROVIDING SUPPORT TO A COLD FRONT ANALYZED FROM 32N49W TO 25N57W THEN WESTWARD AS A STATIONARY FRONT TO EASTERN CUBA. THE SUPPORTING MID/UPPER TROUGH ASSOCIATED WITH THE FRONT IS LIFTING NE...WHICH WILL ALLOW THE FRONT TO GRADUALLY BECOME DIFFUSE THROUGH THE NEXT 24 TO 36 HOURS. SCATTEROMETER DATA INDICATE FRESH NW TO N FLOW BEHIND THE FRONT N OF 30N W OF THE FRONT TO 58W. NO SIGNIFICANT WEATHER APPEARS ACTIVE ALONG THE FRONT AT THIS TIME. FARTHER EAST...BROAD RIDGING DOMINATES THE EASTERN N ATLC S OF 32N...WITH A 1023 MB SURFACE HIGH CENTERED NEAR 30N35W. THIS HIGH IS EXPECTED TO PUSH RAPIDLY EAST THROUGH TUE AHEAD OF THE APPROACHING WEAK SHORT WAVE...AND FOLLOWING ANOTHER WEAK SHORT WAVE SHOWING UP IN WATER VAPOR IMAGERY AND SATELLITE DERIVED WINDS FROM 25N23N TO 15N40W. ASIDE FROM UPPER CIRRUS ASSOCIATED WITH THIS SHORT WAVE...AND WIDELY DISPERSED FIELDS OF STRATO CUMULUS CLOUDS...DEEP LAYER MOISTURE REMAINS LIMITED AND NO APPRECIABLE WEATHER IS NOTED E OF 35W. MODERATE TO FRESH TRADE WIND PERSIST S OF 20N TO THE S OF THE RIDGE AXIS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ CHRISTENSEN