000 AXNT20 KNHC 301749 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED APR 30 2014 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N11W TO 04N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 04N20W TO 03N26W TO THE EQUATOR NEAR 29W. SCATTERED MODERATE CONVECTION IS S OF 06N BETWEEN THE PRIME MERIDIAN AND 13W. WIDELY SCATTERED MODERATE CONVECTION IS S OF 06W BETWEEN 13W- 29W. ...DISCUSSION... GULF OF MEXICO... A VERY BROAD AND VIGOROUS MIDDLE TO UPPER LEVEL LOW IS CENTERED OVER THE UPPER-MISSISSIPPI RIVER VALLEY THIS AFTERNOON THAT SUPPORTS A 1004 MB SURFACE LOW CENTERED OVER WISCONSIN. THE LOWER SURFACE PRESSURES STRETCH THROUGH THE SE CONUS AS A COLD FRONT ENTERS THE GULF WATERS NEAR MOBILE BAY...EXTENDING SW TO THE MEXICO COAST NEAR 22N98W. MOSAIC DOPPLER RADAR AND LIGHTNING DATA INDICATE A STRONG LINE OF SCATTERED SHOWERS AND TSTMS IS OCCURRING ACROSS THE NE GULF WATERS N OF 27N BETWEEN 83W AND THE COLD FRONT BOUNDARY...INCLUDING INLAND PORTIONS OF THE FLORIDA PANHANDLE AND SW GEORGIA THIS AFTERNOON. OTHERWISE...THE GULF IS DIVIDED BY THE COLD FRONT WITH NORTH-NORTHEASTERLY WINDS WEST OF THE BOUNDARY...GENERALLY IN THE RANGE OF 15 TO 25 KT...AND SOUTH- SOUTHEASTERLY WINDS EAST OF THE BOUNDARY...GENERALLY IN THE RANGE OF 5 TO 15 KT. A FEW ISOLATED SHOWERS AND TSTMS ARE OCCURRING OFF THE TEXAS COAST FROM 27N-28N BETWEEN 95W-97W...AND OFF THE EAST-CENTRAL MEXICO COAST NEAR A 1006 MB LOW CENTERED NEAR 21N95W FROM 20N-22N BETWEEN 94W-97W. BY THURSDAY...THE FRONT IS EXPECTED TO BECOME STATIONARY DRAPED FROM THE FLORIDA BIG BEND REGION SW TO THE BAY OF CAMPECHE. CARIBBEAN SEA... NORTHWESTERLY FLOW ALOFT PREVAILS OVER THE CARIBBEAN ON THE SOUTHWESTERN PERIPHERY OF AN UPPER LEVEL TROUGH OVER THE CENTRAL ATLC. WATER VAPOR IMAGERY INDICATES RELATIVELY DRY AND STABLE CONDITIONS IN THE MIDDLE TO UPPER LEVELS THIS AFTERNOON. THIS IS RESULTING IN RELATIVELY FAIR SKIES...HOWEVER WITH A STRONG PRESSURE IN PLACE DUE TO A RIDGE ACROSS THE SW NORTH ATLC REGION...TRADES PERSIST IN THE RANGE OF 15 TO 25 KT...STRONGEST BETWEEN 70W-80W AND IN THE GULF OF HONDURAS. ELSEWHERE...LOW- LEVEL MOISTURE CONVERGENCE INCREASES ACROSS THE SW CARIBBEAN AS A FEW ISOLATED SHOWERS AND TSTMS ARE OCCURRING S OF 10N. THIS ACTIVITY IS LIKELY ENHANCED DUE TO THE CLOSE PROXIMITY OF THE MONSOON TROUGH AXIS EXTENDING ALONG 09N/10N. ...HISPANIOLA... CURRENTLY DRY AND STABLE NORTHWESTERLY FLOW ALOFT IS PROVIDING FAIR CONDITIONS ACROSS THE ISLAND. GIVEN PEAK AFTERNOON HEATING AND INSTABILITY...A FEW ISOLATED SHOWERS AND TSTMS ARE POSSIBLE THIS AFTERNOON INTO THE EVENING HOURS. ANY ONGOING CONVECTION WILL LIKELY DIMINISH GRADUALLY LATE EVENING INTO THE OVERNIGHT HOURS. ATLANTIC OCEAN... OVERALL RIDGING ALOFT IS NOTED ON WATER VAPOR IMAGERY OVER THE SW NORTH ATLC THAT SUPPORTS A SURFACE RIDGE EXTENDING ALONG 70W. HOWEVER...WATER VAPOR IMAGERY ALSO INDICATES THE GRADUAL APPROACH OF WEATHER ASSOCIATED WITH A MIDDLE TO UPPER LEVEL LOW CENTERED OVER THE GREAT LAKES REGION. WHILE THE COLD FRONT ASSOCIATED WITH THIS LOW REMAINS ANALYZED ACROSS THE SE CONUS AND PORTIONS OF THE GULF OF MEXICO...SCATTERED SHOWERS AND TSTMS ARE INITIATING THIS AFTERNOON ALONG THE ATLC COAST FROM JACKSONVILLE FLORIDA NORTHWARD INTO EASTERN NORTH CAROLINA. THE COLD FRONT IS EXPECTED TO EMERGE OFF THE COAST BY EARLY FRIDAY. FARTHER EAST...A MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM 37N45W TO 28N56W AND SUPPORTS A COLD FRONT ANALYZED FROM 32N42W SW TO 27N50W TO 26N57W. A PRE-FRONTAL SURFACE TROUGH LIES TO THE SOUTH OF THE COLD FRONT FROM 27N46W TO 23N60W. ISOLATED SHOWERS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF THE COLD FRONT AND ISOLATED SHOWERS AND TSTMS ARE OCCURRING WITHIN 60 NM EITHER SIDE OF A LINE FROM 32N40W TO 24N48W AND WITHIN 45 NM EITHER SIDE OF THE SURFACE TROUGH AXIS. OTHERWISE...THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1022 MB HIGH CENTERED SE OF THE AZORES NEAR 36N22W. THE SURFACE RIDGE AXIS EXTENDS FROM THE HIGH CENTER SW TO 20N44W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN