000 AXNT20 KNHC 162347 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SUN JUN 16 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... TROPICAL WAVE EXTENDS FROM 13N84W TO 21N82W MOVING W-NW AT 5-10 KT. THE WAVE REMAINS EMBEDDED WITHIN A LARGE AREA OF DEEP LAYERED MOISTURE ACROSS THE CARIBBEAN SEA WITH THE HIGHEST VALUES OF TOTAL PRECIPITABLE WATER NOTED ON IMAGERY FROM 09N-20N BETWEEN 77W-88W. A SEEMINGLY WELL-DEFINED MID-LEVEL CIRCULATION IS EVIDENT ON SATELLITE IMAGERY THIS EVENING...HOWEVER THE AREA LACKS ANY DEFINED AND ORGANIZED LOW-LEVEL CIRCULATION CENTER AT THIS TIME. OVER THE PAST 24 HOURS...MID-LEVEL TROUGHING AROUND 700 MB HAS SHARPENED AND CONTINUES TO MIRROR THE WAVE AXIS ACROSS NICARAGUA AND HONDURAS. REMAINING ENERGY IS EXPECTED TO CONTINUE W-NW OVER THE NEXT FEW DAYS BRINGING INCREASED CLOUDINESS AND PRECIPTATION TO CENTRAL AMERICA AND EVENTUALLY THE YUCATAN PENINSULA AND SOUTHERN MEXICO BY TUESDAY. SCATTERED MODERATE CONVECTION IS FROM 13N-21N BETWEEN 78W-92W. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 04N53W TO 09N51W MOVING W-NW AT 10-15 KT. THE WAVE REMAINS LOW-AMPLITUDE AND HAS LARGELY BEEN EMBEDDED WITHIN THE ITCZ AS IT HAS TRACKED WESTWARD OVER THE PAST FEW DAYS. AN EARLIER MORNING ASCAT PASS AROUND 16/1326 UTC SHOWED LOW-LEVEL CYCLONIC FLOW IN THE VICINITY OF THE WAVE WITH STRONG NE WINDS LOCATED TO THE NORTHWEST OF THE AXIS. GLOBAL MODEL GUIDANCE ALSO INDICATES THE WAVE COINCIDES WITH A WEAK 700 MB TROUGH. WIDELY SCATTERED MODERATE CONVECTION IS FROM 04N-10N BETWEEN 49W-56W. IT IS ANTICIPATED THE WAVE WILL TRACK W-NW OVER THE NEXT FEW DAYS TOWARDS THE SE CARIBBEAN SEA AND EVENTUALLY INTERACT WITH AN UPPER LEVEL LOW FORECAST TO DEVELOP MONDAY INTO TUESDAY NORTH OF PUERTO RICO IN THE VICINITY OF 23N65W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 10N14W TO 08N23W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 08N23W TO 07N28W TO 08N37W TO 06N44W TO 06N50W. ISOLATED MODERATE CONVECTION IS FROM 06N-12N BETWEEN 10W-17W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 05N-11N BETWEEN 34W-49W. ...DISCUSSION... GULF OF MEXICO... NORTHERLY UPPER LEVEL FLOW IS NOTED ON WATER VAPOR IMAGERY W OF 88W WITH MID-LEVEL RIDGING EXTENDING OVER THE NORTHERN GULF ALONG 27N. THIS OVERALL ATMOSPHERIC REGIME IS PROVIDING MOST OF THE GULF WITH STABLE AND DRY CONDITIONS THIS EVENING WITH CLEAR SKIES. A 1019 MB SURFACE HIGH CENTERED NEAR 28N86W IS FURTHER PROMOTING THE FAIR WEATHER. THE ONE EXCEPTION TO FAIR WEATHER IS ASSOCIATED WITH A MID-LEVEL SHORTWAVE TROUGH PROGRESSING OVER THE LOWER MISSISSIPPI RIVER VALLEY. WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING N OF 28N BETWEEN 87W-90W... INCLUDING INLAND PORTIONS OF SOUTHERN ALABAMA...MISSISSIPPI... AND PORTIONS OF FAR EASTERN LOUISIANA. CONVECTION IS ALSO NOTED ACROSS PORTIONS OF THE WESTERN FLORIDA PENINSULA DUE TO AFTERNOON AND EARLY EVENING SEABREEZE DYNAMICS. LOOKING AHEAD... THE TROPICAL WAVE ANALYZED ACROSS THE NW CARIBBEAN SEA WILL CONTINUE MOVING W-NW ACROSS THE YUCATAN PENINSULA AND ANY REMAINING ENERGY WILL EMERGE INTO THE SOUTH-CENTRAL AND SW GULF TUESDAY. CARIBBEAN SEA... THE PRIMARY FEATURE ACROSS THE WESTERN CARIBBEAN THIS EVENING IS THE TROPICAL WAVE MENTIONED ABOVE ALONG 83W. THE WAVE AT THE SURFACE IS LOCATED BELOW A MOSTLY DIFFLUENT REGIME WITH OUTFLOW AND HIGH-LEVEL CIRRUS CLOUDINESS FANNING NORTHWARD ACROSS THE NORTHERN YUCATAN PENINSULA...CUBA...AND PORTIONS OF THE BAHAMAS THIS EVENING. MOISTURE ASSOCIATED WITH THE WAVE AND THE ASSOCIATED DIFFLUENCE STRETCHES EASTWARD FROM THE NW CARIBBEAN OVER EASTERN CUBA...THE WINDWARD PASSAGE AND HISPANIOLA. ASIDE FROM CONVECTION ASSOCIATED WITH THE TROPICAL WAVE...SCATTERED SHOWERS AND TSTMS ARE OCCURRING FROM 18N-22N BETWEEN 67W-78W. THE WAVE IS ANTICIPATED TO DRIFT W-NW OVER THE NEXT FEW DAYS CROSSING CENTRAL AMERICA AND THE YUCATAN PENINSULA WITH CONTINUED HEAVY RAINFALL EXPECTED AND A HIGHER POTENTIAL FOR LOCALIZED FLOODING AND MUDSLIDES. OTHERWISE...THE CENTRAL AND EASTERN CARIBBEAN S OF 18N E OF 75W IS UNDER THE INFLUENCE OF NW FLOW ALOFT AND OVERALL GENERAL WEAK SUBSIDENCE DUE TO THE NORTHEASTERN PERIPHERY OF AN ANTICYCLONIC CIRCULATION CENTERED NEAR 13N76W. CONDITIONS REMAIN FAIR THIS EVENING FOR THE LESSER ANTILLES AND ABC ISLANDS. HISPANIOLA... CURRENTLY AFTERNOON AND EARLY EVENING TSTMS CONTINUE TO DIMINISH ACROSS WESTERN PORTIONS OF THE ISLAND DUE TO THE BASE OF A SW NORTH ATLC MIDDLE TO UPPER LEVEL TROUGH EXTENDING FROM 32N61W TO A BASE OVER THE TURKS AND CAICOS ISLANDS NEAR 21N72W. WATER VAPOR IMAGERY INDICATES THE TROUGH IS JUST BEGINNING TO SHOW HINTS OF BREAKING OFF A CUT-OFF LOW WHICH IS FORECAST TO DEVELOP NORTH OF PUERTO RICO BY LATE MONDAY INTO TUESDAY NEAR 24N65W. WITH THE UPPER LEVEL LOW FORECAST TO DEVELOP NE OF THE ISLAND...NW FLOW IS EXPECTED TO DOMINATE THE EARLY PART OF THE WEEK. OVERALL STABLE CONDITIONS ARE EXPECTED TO PREVAIL ALOFT...HOWEVER AFTERNOON AND EARLY EVENING ISOLATED SHOWERS AND TSTMS WILL CONTINUE TO BE POSSIBLE WITH PEAK DAYTIME HEATING AND INSTABILITY. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL TROUGH DOMINATES OVER THE SW NORTH ATLC WITH AXIS EXTENDING FROM 32N61W TO A BASE NORTH OF HISPANIOLA NEAR 22N72W. WHILE MOST OF THE ENERGY ASSOCIATED WITH THIS UPPER LEVEL FEATURE REMAINS N OF 25N...THE TROUGHING SUPPORTS A COLD FRONT ANALYZED FROM 32N57W SW TO 29N61W THEN W-SW AS A DISSIPATING STATIONARY FRONT TO 27N69W. A PAIR OF SURFACE TROUGHS OFFSHOOT FROM THE FRONTAL BOUNDARY ONE FROM 31N58W TO 27N60W...THE OTHER FROM 28N64W TO 24N68W. WHILE THE SURFACE BOUNDARIES ARE PROVIDING A PORTION OF THE FORCING FOR CONVECTION...MOST OF THE SCATTERED SHOWERS AND TSTMS ARE A RESULT OF MIDDLE TO UPPER LEVEL DIFFLUENCE OCCURRING FROM WITHIN 120 NM EITHER SIDE OF A LINE FROM 32N57W TO 25N62W TO 20N67W TO 20N77W...INCLUDING PORTIONS OF HISPANIOLA...THE WINDWARD PASSAGE...AND EASTERN CUBA. OTHERWISE...THE SW NORTH ATLC N OF 22N W OF 68W REMAINS FAIRLY QUIET THIS EVENING. FARTHER EAST... THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1031 MB HIGH CENTERED NEAR 36N39W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN