000 AXNT20 KNHC 301746 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU APR 30 2015 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 09N13W TO 06N16W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N16W TO 01N28W TO 03N39W TO THE EQUATOR NEAR 50W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM EITHER SIDE OF A LINE FROM 04N19W TO 04N40W TO 01N51W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR IMAGERY OVER THE CAROLINAS WITH THE PARENT MIDDLE TO UPPER LEVEL LOW CENTERED OVER THE GREAT LAKES REGION. THE SHORTWAVE TROUGH SUPPORTS A BROAD AREA OF LOW PRESSURE ACROSS THE SW NORTH ATLC AREA FOCUSED ON A 1003 MB LOW CENTERED NEAR 31N77W. THE ASSOCIATED COLD FRONT EXTENDS FROM THE LOW CENTER TO THE SOUTHERN FLORIDA PENINSULA TO THE LOWER FLORIDA KEYS TO ACROSS THE CENTRAL YUCATAN PENINSULA. SOUTHWESTERLY FLOW PREVAILS ALOFT OVER THE GULF WITH PLENTY OF MIDDLE TO UPPER LEVEL MOISTURE AND CLOUDINESS COVERING THE GULF GENERALLY S OF 28N. A WEAKER SECONDARY WAVE OF ENERGY IS ANALYZED AS A SURFACE TROUGH EXTENDING FROM THE TAMPA BAY REGION W-SW TO 26N93W WITH A DRIER AND MORE STABLE AIRMASS TO ITS NORTH. OTHERWISE...A RIDGE ANCHORED BY A 1019 MB HIGH CENTERED NEAR TUXPAN MEXICO IS PROVIDING MUCH OF THE GULF WITH GENTLE TO MODERATE NORTHERLY BREEZE CONDITIONS WHICH ARE EXPECTED TO PERSIST ON THE EASTERN PERIPHERY OF THE RIDGE THROUGH SATURDAY. CARIBBEAN SEA... WATER VAPOR IMAGERY INDICATES MUCH OF THE CARIBBEAN BASIN IS UNDER THE INFLUENCE OF DRY AND STABLE FLOW ALOFT ASSOCIATED WITH AN UPPER LEVEL ANTICYCLONE CENTERED NEAR 18N67W. THE ANTICYCLONE IS PROVIDING FOR OVERALL MOSTLY CLEAR SKIES AND FAIR CONDITIONS THIS AFTERNOON GENERALLY E OF 78W. W OF 78W...ON THE FAR WESTERN PERIPHERY OF THE UPPER LEVEL RIDGING...MID-LEVEL MOISTURE INCREASES AS SOUTHWESTERLY FLOW IS NOTED TO THE NORTH ACROSS THE GULF OF MEXICO. IN ADDITION...A COLD FRONT EXTENDS FROM OFFSHORE OF WESTERN CUBA ACROSS THE YUCATAN CHANNEL TO THE NE TIP OF THE YUCATAN PENINSULA WITH A PRE-FRONTAL SURFACE TROUGH EXTENDING FROM 21N83W INTO A 1009 MB LOW NEAR 18N85W TO WESTERN HONDURAS NEAR 15N87W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE MOSTLY FOCUSED IN THE VICINITY OF THE SURFACE TROUGH...HOWEVER OVERALL THE ACTIVITY REMAINS N OF 15N W OF 82W. WHILE THE FRONT WEAKENS DURING THE NEXT 24 HOURS ACROSS THE NW CARIBBEAN...THE MAIN MARINE IMPACT IS FRESH TO OCCASIONAL STRONG BREEZE CONDITIONS GENERALLY E OF 75W DUE TO A STRENGTHENED PRESSURE GRADIENT ACROSS THE EASTERN CARIBBEAN. THESE CONDITIONS ARE EXPECTED TO PERSIST THROUGH EARLY SATURDAY. ...HISPANIOLA... MOSTLY CLEAR SKIES PREVAIL THIS AFTERNOON AND ARE EXPECTED TO PERSIST DURING THE NEXT FEW DAYS AS DRY UPPER LEVEL ANTICYCLONIC FLOW ALOFT MAINTAINS STABLE ATMOSPHERIC CONDITIONS ACROSS THE REGION. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR IMAGERY OVER THE CAROLINAS THAT SUPPORTS A 1003 MB LOW CENTERED NEAR 31N77W. THE ASSOCIATED COLD FRONT EXTENDS SW FROM THE LOW CENTER TO THE SOUTHERN FLORIDA PENINSULA AND LOWER FLORIDA KEYS TO THE YUCATAN PENINSULA. IN ADDITION...A WARM FRONT EXTENDS EAST TO 30N70W WHERE THE FRONT BECOMES STATIONARY TO 31N57W. WEST-SOUTHWESTERLY FLOW ALOFT EXTENDS FROM OVER SOUTHERN MEXICO AND THE GULF OF MEXICO INTO THE SW NORTH ATLC THAT IS ADVECTING MOISTURE AND AIDING THE GENERATION OF WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ALONG AND IN THE VICINITY OF THE FRONTS N OF 26N BETWEEN 35W-68W...AND N OF 23N W OF 68W. THE AREA OF LOW PRESSURE IS FORECAST TO DEVELOP FURTHER AS IT MOVES NORTH OF THE DISCUSSION AREA FRIDAY. THE ASSOCIATED COLD FRONT WILL INTRODUCE FRESH TO STRONG WEST-NORTHWESTERLY WINDS GENERALLY N OF 28N IN WAKE OF THE BOUNDARY. OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1025 MB HIGH CENTERED NEAR 35N15W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN