000 AXNT20 KNHC 291038 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE APR 29 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1030 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 07N11W TO 04N17W 03N23W. THE INTERTROPICAL CONVERGENCE ZONE AXIS BEGINS NEAR 03N23W AND CONTINUES ALONG 01N30W TO 0S50W. SCATTERED MODERATE CONVECTION AND ISOLATED TSTMS ARE FROM 01S-11N E OF 27W AND FROM 01S-04N W OF 28W. ...DISCUSSION... GULF OF MEXICO... WESTERLY FLOW IS ACROSS THE BASIN ALOFT WITH WATER VAPOR IMAGERY INDICATING THE PRESENCE OF DRY AIR OVER MUCH OF THE GULF. EXCEPT FOR THE NW GULF WHERE MODERATE MOIST CONTENT IS NOTED ON THE SSMI TPW IMAGERY...DRY AIR ALSO DOMINATES AT THE LOWER LEVELS WHICH IS SUPPORTING MOSTLY FAIR WEATHER AND CLEAR SKIES. OVER THE NW BASIN...LOWER LEVEL MOISTURE AND S-SE WIND FLOW SUPPORT ADVECTION FOG N OF 27N W OF 89W. MIDDLE TO UPPER LEVEL DIFFLUENCE OVER THE EASTERN CONUS IS SUPPORTING A SQUALL LINE THAT EXTENDS FROM W CENTRAL GEORGIA SW TO SE LOUISIANA. THIS SQUALL LINE IS GENERATING HEAVY SHOWERS AND TSTMS WHICH EXTENDS OFFSHORE THE NE GULF COAST...N OF 29N E OF 90W. OTHERWISE...S-SE FLOW OF 10-15 KT DOMINATE ACROSS THE WESTERN GULF AHEAD OF THE NEXT FRONT TO ENTER THE NW BASIN AS A COLD FRONT LATER TODAY. A TIGHTER PRESSURE GRADIENT OVER THE EASTERN GULF SUPPORT S-SE WINDS OF 15-20 KT. WINDS ARE FORECAST TO SHIFT N-NE WEST OF THE NEXT COLD FRONT TUESDAY INTO THU NIGHT AS SURFACE RIDGING BUILDS INTO THE SOUTHERN PLAINS AND ALONG THE MEXICO COAST. CARIBBEAN SEA... WESTERLY FLOW ALOFT PREVAILS OVER THE CARIBBEAN WITH WATER VAPOR IMAGERY INDICATING DRY AND STABLE CONDITIONS ACROSS THE BASIN. AT THE LOWER LEVELS...SSMI TPW IMAGERY INDICATE MODERATE MOISTURE ACROSS THE NW AND CENTRAL CARIBBEAN AND HIGH MOISTURE CONTENT OVER THE SW CARIBBEAN. HOWEVER...WITHOUT ANY LIFTING MECHANISM IN PLACE FAIR WEATHER IS BEING FAVORED. OTHERWISE...A SLIGHT TIGHTER PRESSURE GRADIENT ACROSS THE CENTRAL AND FAR WESTERN BASIN SUPPORTS WINDS OF 20-25 KT WHILE A MORE RELAXED GRADIENT ACROSS THE REMAINDER BASIN SUPPORTS WINDS OF 10-15 KT. NO MAJOR CHANGES ARE EXPECTED WITHIN THE NEXT 48 HOURS. ...HISPANIOLA... CURRENTLY...DRY STABLE AIR AT THE UPPER AND LOWER LEVELS FAVORS FAIR WEATHER. EXCEPT FOR AFTERNOON SHOWERS...THESE WEATHER CONDITIONS ARE EXPECTED TO PREVAIL THROUGH WED NIGHT. ATLANTIC OCEAN... A SHORT WAVE MIDDLE TO UPPER LEVEL TROUGH OVER THE SW N ATLC WITH BASE OVER CUBA IS SUPPORTING AN AREA SHOWERS AND TSTMS FROM 21N-24N BETWEEN 75W-80W. OVER THE NW ATLC WATERS...A MIDDLE TO UPPER LEVEL LOW CENTERED NEAR 38N59W AND ITS ASSOCIATED TROUGH SUPPORT A WEAK COLD FRONT ANALYZED FROM 30N57W TO 28N65W AND A PRE-FRONTAL TROUGH FROM 28N55W TO 25N63W. THERE IS NO CONVECTION ASSOCIATED WITH THESE SURFACE FEATURES AT THIS TIME. TWO 1017 MB HIGH PRESSURE CENTERS SURROUND THE FRONT...ONE NEAR 30N69W AND ANOTHER NEAR 23N58W...BOTH DISSIPATING WITHIN THE NEXT 24 HOURS. AN AREA OF ISOLATED SHOWERS AND TSTMS IS NOTED ON SATELLITE IMAGERY FROM 25N-28N BETWEEN 46W-52W. OTHERWISE...THE REMAINDER OF THE EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1022 MB HIGH CENTERED NEAR 35N21W. THE COLD FRONT IS FORECAST TO CONTINUE TO MOVE EASTWARD ACROSS THE BASIN THROUGH THU NIGHT. SURFACE RIDGING WILL DOMINATE ELSEWHERE. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR