000 AXNT20 KNHC 160015 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED MAY 15 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 2315 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 08N41W TO 02N42W MOVING W AT 15 KT. THE WAVE REMAINS LOW-AMPLITUDE AND EMBEDDED WITHIN THE ITCZ AXIS. TOTAL PRECIPITABLE WATER AND SATELLITE IMAGERY ALSO INDICATE A MAXIMUM IN LOW-LEVEL MOISTURE CONVERGENCE AND CLOUDINESS WITH SOME SHOWER ACTIVITY IN THE VICINITY OF THE WAVE AXIS. THE WAVE IS EXPECTED TO CONTINUE MOVING WESTWARD. MOISTURE ASSOCIATED WITH THIS FEATURE SHOULD REACH THE WINDWARD ISLANDS DURING THE UPCOMING WEEKEND. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE COAST OF GUINEA BISSAU NEAR 12N15W TO 06N20W. THE INTERTROPICAL CONVERGENCE ZONE AXIS CONTINUES FROM 06N20W TO 05N40W TO THE EQUATOR NEAR 50W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS FROM 03N- 07N BETWEEN 07W-14W...AND FROM 04N-07N BETWEEN 17W-24W. SIMILAR CONVECTION IS ALSO NOTED FROM 03N-07N W OF 42W. ...DISCUSSION... GULF OF MEXICO... A RIDGE AT THE SURFACE AND ALOFT DOMINATES THE GULF WATERS. MIDDLE TO UPPER LEVEL LOW CENTERED OVER THE TEXAS PANHANDLE AND WESTERN OKLAHOMA AND THE ASSOCIATED SHORTWAVE TROUGH AXIS EXTENDING OVER WEST TEXAS AND NW MEXICO IS SUPPORTING SOME SHOWERS AND ISOLATED TSTMS ACROSS PORTIONS OF THE NW GULF AND EASTERN TEXAS. MAINLY GENTLE TO MODERATE WINDS ARE NOTED AROUND A 1022 MB HIGH PRES LOCATED OVER THE NE GULF NEAR 29N84W AT 2100 UTC. THE RIDGING IS SUPPORTED ALOFT BY A MIDDLE TO UPPER LEVEL RIDGE WITH AXIS ALONG 87W/88W WHICH IS PROVIDING MAINLY FAIR CONDITIONS ACROSS THE EASTERN GULF. LOOKING AHEAD...THE RIDGE WILL EXTEND FROM THE WESTERN ATLC ACROSS THE NORTHERN GULF THROUGH THE REMAINDER OF THE WEEK. SE WINDS WILL INCREASE OVER THE NW GULF BY SUN BETWEEN THE RIDGE TO THE EAST AND AN APPROACHING TROUGH MOVING ACROSS TEXAS. CARIBBEAN SEA... AN UPPER LEVEL RIDGE COVERS THE WESTERN CARIBBEAN...THE YUCATAN PENINSULA AND WESTERN CUBA WITH MODERATE TO STRONG SUBSIDENCE AND IMPLIED DRY AIR MASS. THE TAIL END OF AN UPPER LEVEL TROUGH LOCATED N OF AREA IS HELPING TO INDUCE CONVECTION OVER THE VIRGIN ISLANDS...PUERTO RICO AND HISPANIOLA...INCLUDING ALSO THE COASTAL WATERS. VERY HEAVY RAIN WAS REPORTED IN PARTS OF PUERTO RICO DURING THE AFTERNOON...PARTICULARLY ACROSS THE EAST AND SOUTHEAST SECTIONS OF THE ISLAND. THE TROUGH IS FORECAST TO MOVE EASTWARD ACROSS THE NE CARIBBEAN THU AND FRI WITH THE AXIS REACHING THE NORTHERN LEEWARD ISLANDS FRI MORNING. TYPICAL TRADE WIND SHOWERS ARE SEEN ACROSS THE EAST AND CENTRAL CARIBBEAN... MORE CONCENTRATED SOUTH OF PUERTO RICO. FRESH TO STRONG TRADE WINDS CONTINUE TO BLOW ACROSS THE SOUTH-CENTRAL CARIBBEAN AND ALONG THE COAST OF COLOMBIA WHILE MODERATE TO FRESH TRADE WINDS PERSIST ELSEWHERE. IN ADDITION...MODERATE TO FRESH NE WINDS ARE TRANSPORTING SOME CLOUDINESS WITH EMBEDDED SHOWERS FROM THE ATLC ACROSS EAST CENTRAL CUBA. HISPANIOLA... THE COMBINATION OF AN UPPER LEVEL TROUGH WITH THE DIURNAL HEATING AND LOCAL EFFECTS SUPPORTS THE SHOWER AND TSTMS ACTIVITY NOTED LATE THIS AFTERNOON OVER PARTS OF HAITI AND DOMINICAN REPUBLIC. CURRENTLY...THE ACTIVITY APPEARS MORE CONCENTRATED NEAR THE BORDER OF THESE COUNTRIES. LOCALIZED FLOODING AND SOME GUSTY WINDS MAY OCCUR IN ASSOCIATION WITH THESE SHOWERS AND TSTMS. COMPUTER MODEL SHOWS MOISTURE PERSISTING OVER THE ISLAND ON THU RESULTING IN ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS MAINLY DURING THE AFTERNOON HOURS. ATLANTIC OCEAN... MIDDLE TO UPPER LEVEL RIDGING WITH AXIS CURRENTLY OVER THE GULF OF MEXICO IS PROVIDING MOST OF THE SW NORTH ATLC W OF 65W WITH DRY NW FLOW ALOFT. A 1025 MB HIGH IS CENTERED NEAR 32N71W THAT IS EXPECTED TO SHIFT EASTWARD OVER THE NEXT 24 TO 36 HOURS. THIS SYSTEM EXTENDS A RIDGE OVER THE WESTERN ATLC. MODERATE TO FRESH NE FLOW IS NOTED ON THE SOUTHERN PERIPHERY OF THE RIDGE OVER THE BAHAMAS AND CUBA. LINE OF CLOUDINESS WITH EMBEDDED SHOWERS ARE NOTED ON VISIBLE SATELLITE IMAGERY PARALLEL TO THIS FLOW. EAST OF THE RIDGE...THERE IS AN UPPER LEVEL TROUGH THAT ENTERS THE DISCUSSION AREA NEAR 31N60W TRAILING S-SW TO 25N62W TO A BASE OVER HISPANIOLA NEAR 19N70W. THIS TROUGHING SUPPORTS A COLD FRONT ANALYZED FROM 31N60W TO 25N65W TO THE SE BAHAMAS WHERE IT IS DISSIPATING. NORTHERLY WINDS OF 15-20 KT ARE OBSERVED BY SCATTEROMETER DATA IN THE WAKE OF THE FRONT. SOUTHERLY WINDS WITH SIMILAR WIND SPEEDS ARE JUST AHEAD OF THE FRONT MAINLY N OF 25N. THE FRONT WILL CONTINUE TO DISSIPATE WEST OF 65W THU. THE REMAINDER OF THE CENTRAL AND EASTERN ATLC ARE UNDER THE INFLUENCE OF SURFACE RIDGING WITH THE EXCEPTION OF A WEAK 1018 MB LOW PRES LOCATED NEAR 29N41W. A TROUGH EXTENDS FROM 32W40W TO LOW CENTER TO 25N45W. PRES GRADIENT BETWEEN HIGH PRES TO THE N AND THE LOW PRES IS PRODUCING AN AREA OF FRESH TO STRONG NE TO E WINDS WITHIN AROUND 420 NM E OF THE TROUGH AXIS. AN EARLIER ASCAT PASS PROVIDED OBSERVATIONS OF THESE WINDS. ISOLATED SHOWERS ARE OCCURRING ON THE EAST SIDE OF THE TROUGH. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GR