000 AXNT20 KNHC 072358 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT FRI JUN 07 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. ...SPECIAL FEATURES... POST-TROPICAL CYCLONE ANDREA IS CENTERED NEAR 37.5N 76.0W AT 08/0000 UTC OR 35 NM NNE OF NORFOLK VIRGINIA AND 65 NM SW OF OCEAN CITY MARYLAND MOVING NE AT 24 KT. ESTIMATED CENTRAL PRESSURE IS 996 MB. MAXIMUM SUSTAINED WIND SPEED IS 40 KT WITH GUSTS TO 50 KT. SCATTERED MODERATE CONVECTION IS FROM 35N-37N BETWEEN 78W-81W. ANDREA IS FORECAST TO TRACK NE ACROSS THE DELMARVA REGION THIS EVENING AND OFFSHORE OF NEW ENGLAND TO NOVA SCOTIA CANADA SATURDAY. SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/WTNT31 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 03N43W TO 09N41W MOVING W AT 5-10 KT. THE WAVE IS EMBEDDED WITHIN THE ITCZ AXIS WITH LOW-LEVEL STREAMLINE ANALYSIS INDICATING BROAD CYCLONIC FLOW IN THE VICINITY OF THE AXIS BETWEEN 40W-47W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 03N-08N BETWEEN 41W-47W. TROPICAL WAVE EXTENDS FROM 14N54W TO 19N52W MOVING W-NW AT 10-15 KT. THE WAVE LIES WITHIN AN AREA OF MAXIMUM DEEP LAYER MOISTURE EVIDENT IN TOTAL PRECIPITABLE WATER IMAGERY FROM 16N-22N BETWEEN 48W-57W. THIS AREA OF MAXIMUM MOISTURE CORRESPONDS WITH SCATTERED MODERATE CONVECTION OCCURRING FROM 17N-23N BETWEEN 48W- 56W. MOIST SOUTHWESTERLY FLOW OVER THIS AREA EAST OF AN UPPER LEVEL TROUGH AXIS IS PROVIDING A DIFFLUENT ENVIRONMENT FOR THE CONVECTION. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 08N19W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 08N19W TO 05N29W TO 04N34W TO 05N43W TO 01N50W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 02N-08N BETWEEN 16W-21W...AND FROM 02N-07N BETWEEN 24W-30W. ...DISCUSSION... GULF OF MEXICO... WATER VAPOR IMAGERY INDICATES BROAD MIDDLE TO UPPER LEVEL TROUGHING IS OVER THE GULF THIS EVENING. MIDDLE TO UPPER LEVEL MOISTURE CONTINUES TO ADVECT NORTH-NORTHEASTWARD OVER PORTIONS OF THE SE GULF AND FLORIDA PENINSULA FOCUSED ON A SURFACE TROUGH ANALYZED FROM 26N87W TO THE YUCATAN PENINSULA NEAR 20N89W. SCATTERED SHOWERS AND TSTMS ARE OCCURRING SE OF A LINE FROM THE TAMPA BAY REGION NEAR 28N83W TO 24N90W TO 20N90W...INCLUDING INLAND PORTIONS OF THE YUCATAN PENINSULA. OTHERWISE...THE UPPER LEVEL TROUGHING SUPPORTS A VERY WEAK COLD FRONT ANALYZED FROM THE FLORIDA PANHANDLE NEAR 31N97W SW TO 28N90W TO THE TEXAS COAST NEAR CORPUS CHRISTI. WEAK MID-LEVEL SHORTWAVE ENERGY EMBEDDED WITHIN THE LONGWAVE TROUGHING IS GENERATING SCATTERED SHOWERS AND TSTMS ACROSS SOUTHERN TEXAS N OF 26N W OF 96W. THE FRONT IS EXPECTED TO DISSIPATE THROUGH THE OVERNIGHT WITH SURFACE RIDGING RE-ESTABLISHING ITSELF OVER THE GULF BY LATE SATURDAY WITH MODERATE TO FRESH E-SE WINDS THROUGH MONDAY. CARIBBEAN SEA... UPPER LEVEL TROUGHING REMAINS OVER THE FAR NW CARIBBEAN WITH TROPICAL MOISTURE CONTINUING TO ADVECT NORTHWARD OVER THE SE GULF OF MEXICO...FLORIDA STRAITS...AND FLORIDA PENINSULA THIS EVENING WITH MOST CONVECTION OVER INLAND PORTIONS OF THE YUCATAN PENINSULA AND NORTH OF THE YUCATAN CHANNEL ACROSS THE SE GULF OF MEXICO. OTHERWISE...MIDDLE TO UPPER LEVEL RIDGING REMAINS DOMINATE OVER THE WESTERN CARIBBEAN BETWEEN 72W-84W AS NORTH- NORTHEASTERLY FLOW PROVIDES AN OVERALL STABLE ENVIRONMENT WITH MOSTLY CLEAR SKIES. FARTHER EAST...THE EASTERN CARIBBEAN E OF 72W IS UNDER THE INFLUENCE OF MOIST SOUTHWESTERLY FLOW WITH MOSTLY HIGH LEVEL CLOUDINESS STREAMING NORTHEAST OFF THE SOUTH AMERICAN CONTINENT INTO THE CENTRAL ATLC. LOWER TO MID-LEVEL MOISTURE IS RELATIVELY HIGHER OVER THE EASTERN CARIBBEAN E OF 69W ACCORDING TO TOTAL PRECIPITABLE WATER IMAGERY THAT RESULTS IN AREAS OF ISOLATED SHOWER ACTIVITY SURROUNDING PUERTO RICO...THE US/UK VIRGIN ISLANDS...AND LESSER ANTILLES. AN APPROACHING TROPICAL WAVE CURRENTLY ALONG 54W WILL SKIRT THE LEEWARD ISLANDS AND NE CARIBBEAN SATURDAY INTO SUNDAY WITH HIGHER PROBABILITIES OF PRECIPITATION EXPECTED. HISPANIOLA... CURRENTLY AFTERNOON AND EARLY EVENING CONVECTION CONTINUES TO DISSIPATE OVER WESTERN PORTIONS OF THE ISLAND AS OVERALL STABLE CONDITIONS PERSIST DUE TO NORTHEASTERLY FLOW ALOFT. WATER VAPOR IMAGERY INDICATES DRIER AIR IS PLACED TO THE EAST OF THE ISLAND OVER THE MONA PASSAGE AND PUERTO RICO AND IS EXPECTED TO DRIFT WESTWARD OVER THE REGION DURING THE NEXT 24 TO 36 HOURS. THE EVENING AND OVERNIGHT SHOULD REMAIN FAIRLY QUIET WITH E-SE WINDS EXPECTED TO CONTINUE THROUGH LATE SATURDAY. ISOLATED AFTERNOON AND EVENING SHOWERS AND TSTMS WILL BE POSSIBLE THE NEXT COUPLE OF DAYS. ATLANTIC OCEAN... MOIST SOUTHWESTERLY FLOW ALOFT IS NOTED BETWEEN MIDDLE TO UPPER LEVEL TROUGHING OVER THE EASTERN CONUS AND AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE SW NORTH ATLC NEAR 26N75W. WITH AN OVERALL DIFFLUENT ENVIRONMENT IN PLACE...AND LOW- LEVEL MOISTURE CONVERGENCE OVER THE SW NORTH ATLC...SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING W OF A LINE FROM 32N72W TO CENTRAL CUBA NEAR 22N79W. OTHERWISE THE REMAINDER OF THE SW NORTH ATLC...ALONG WITH THE CENTRAL AND EASTERN ATLC ARE UNDER THE INFLUENCE OF A BROAD SURFACE RIDGE ANCHORED BY A 1033 MB HIGH CENTERED NEAR 36N43W. ONE AREA OF ACTIVE WEATHER EMBEDDED WITHIN THE SOUTHERN PERIPHERY OF THE RIDGE IS THE TROPICAL WAVE ALONG 54W DISCUSSED ABOVE AND THE OTHER IS A WEAK SURFACE TROUGH ANALYZED FROM 28N29W TO 33N29W WITH POSSIBLE ISOLATED SHOWERS WITHIN 180 NM EITHER SIDE OF THE TROUGH AXIS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN