000 AXNT20 KNHC 090004 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE APR 08 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2345 UTC. ...SPECIAL FEATURES... A COLD FRONT IS ANALYZED FROM THE SW N ATLC NEAR 30N78W SW ACROSS SOUTHERN FLORIDA AND THE YUCATAN CHANNEL TO W OF GUATEMALA. GALE FORCE CONDITIONS ARE EXPECTED TO DEVELOP LATER TONIGHT WITHIN 90 NM NW OF FRONT AS WELL AS IN THE GULF OF HONDURAS. GALE WINDS ARE EXPECTED TO SUBSIDE BY WED AFTERNOON. SEE LATEST NWS HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N12W TO 03N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 03N19W TO THE EQUATOR NEAR 30W TO 01S44W. ISOLATED MODERATE CONVECTION IS FROM 01N-08N BETWEEN 25W-30W AND FROM 06S-01N W OF 27W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY OVER THE EASTERN CONUS WITH AXIS EXTENDING FROM THE GREAT LAKES TO A BASE OVER THE CENTRAL GULF. THIS TROUGH SUPPORTS A COLD FRONT ANALYZED FROM THE SW N ATLC NEAR 30N78W SW ACROSS SOUTHERN FLORIDA FROM 27N80W TO 24N82W TO THE YUCATAN CHANNEL NEAR 22N84W TO THE YUCATAN PENINSULA NEAR 20N87W. MOSAIC DOPPLER RADAR AND LIGHTNING DATA...ALONG WITH SATELLITE IMAGERY INDICATE SCATTERED SHOWERS AND TSTMS OCCURRING OVER CENTRAL AND SOUTHERN FLORIDA AND WITHIN 160 NM AHEAD OF THE FRONT OVER THE SE GULF. THE STRONGEST CONVECTION IS OCCURRING ON THE STRAITS OF FLORIDA W OF 81W AS WELL AS WESTERN CUBA AND ADJACENT WATERS. THE CONVECTIVE ACTIVITY IS BEING ENHANCED BY MIDDLE TO UPPER LEVEL DIFFLUENCE AND MOISTURE ADVECTION FROM THE EASTERN PACIFIC BY SOUTHWESTERLY FLOW ALOFT. OVER THE NORTHERN GULF...SHOWERS AND TSTMS ARE OCCURRING N OF 28N BETWEEN 87W-90W ASSOCIATED WITH AN AREA OF LOW PRESSURE OVER SE LOUISIANA...SOUTHERN MISSISSIPPI AND SOUTHERN ALABAMA. OTHERWISE...RIDGING HAS BUILT IN ACROSS THE GULF WEST OF THE FRONT. GALE FORCE WINDS ARE EXPECTED TO DEVELOP NW OF THE FRONT NEAR THE YUCATAN CHANNEL LATER TONIGHT. SEE THE SPECIAL FEATURES ABOVE FOR MORE DETAILS. AS THE COLD FRONT SWEEPS EASTWARD AND CLEARS THE BASIN LATER TONIGHT...STRONG NORTH-NORTHWESTERLY WINDS ARE EXPECTED TO PERSIST THROUGH WEDNESDAY AFTERNOON. THEREAFTER...THE PRESSURE GRADIENT WILL RELAX SOMEWHAT AS HIGH PRESSURE DRIFTS ACROSS THE NORTHERN GULF THROUGH FRIDAY AFTERNOON. CARIBBEAN SEA... A COLD FRONT BEING SUPPORTED BY A DEEP LAYER TROUGH ACROSS THE EASTERN CONUS IS ENTERING THE FAR NW CARIBBEAN SEA. AS OF 2100 UTC...A PORTION OF THE COLD FRONT EXTENDS FROM NW CUBA NEAR 22N84W TO THE NE YUCATAN PENINSULA NEAR 20N87W. A PRE-FRONTAL SURFACE TROUGH EXTENDS FROM 20N85W TO NW HONDURAS NEAR 15N88W. SCATTERED SHOWERS AND TSTMS ASSOCIATED WITH THESE FEATURES ARE N OF 17N W OF 84W. A MIDDLE TO UPPER LEVEL RIDGE IS ANCHORED OVER THE CENTRAL CARIBBEAN NEAR 14N76W WITH WATER VAPOR IMAGERY INDICATING THE AIRMASS INFLUENCING THE REMAINING BASIN IS VERY DRY AND STABLE. THIS STABILITY ALOFT CONTINUES TO IMPACT THE SURFACE CONDITIONS WITH MOSTLY CLEAR SKIES AND FAIR WEATHER. A STRONG PRESSURE GRADIENT BETWEEN A SURFACE RIDGE ACROSS THE SW NORTH ATLC TO THE NORTH-NORTHEAST AND LOWER PRESSURE TO THE SOUTH ACROSS NORTHERN SOUTH AMERICA CONTINUES TO SUSTAIN STRONG TRADE WINDS OF 20 KT WITH THE STRONGEST WINDS UP TO 25 KT NOTED BETWEEN 67W-75W. THE COLD FRONT WILL CONTINUE TO MOVE ACROSS THE WESTERN CARIBBEAN THROUGH WED NIGHT WHEN IT IS EXPECTED TO START DISSIPATING FROM EASTERN CUBA SW TO EASTERN NICARAGUA. ...HISPANIOLA... MIDDLE TO UPPER LEVEL DRY AND STABLE AIR AS WELL AS NORTHERLY FLOW CONTINUE TO SUPPORT MOSTLY FAIR CONDITIONS ACROSS THE ISLAND. OTHERWISE...ISOLATED SHOWERS ARE OBSERVED OVER CENTRAL HAITI BEING ENHANCED BY A LOW LEVEL MOIST AIRMASS. AN APPROACHING FRONTAL BOUNDARY MOVING ACROSS CUBA AND THE SW NORTH ATLC TO THE NORTH WILL BEGIN TO IMPACT HISPANIOLA WITH AN INCREASE IN MOISTURE...CLOUDINESS...AND A HIGHER PROBABILITY OF PRECIPITATION DURING THE DAY ON THURSDAY. THE FRONT WILL LIKELY STALL NW OF THE ISLAND PROVIDING CONTINUED ISOLATED SHOWERS ON FRIDAY. ATLANTIC OCEAN... A DEEP LAYER TROUGH ACROSS THE EASTERN CONUS IS SUPPORTING A COLD FRONT THAT AT 2100 UTC EXTENDS FROM THE SW N ATLC NEAR 30N78W ACROSS SOUTHERN FLORIDA FROM 27N80W TO 24N82W TO THE YUCATAN CHANNEL NEAR 22N84W TO THE YUCATAN PENINSULA NEAR 20N87W. SCATTERED MODERATE CONVECTION AND TSTMS ASSOCIATED WITH THE FRONT ARE N OF 26N W OF 76W. FARTHER EAST...A MIDDLE TO UPPER LEVEL LOW IS CENTERED SW OF THE IBERIAN PENINSULA NEAR 38N15W SUPPORTING A WEAKENING 1015 MB LOW CENTERED NEAR 29N22W. THERE IS NO CONVECTION ASSOCIATED WITH THE LOW. OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A THE BROAD RIDGE ANCHORED NEAR 42N50W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR