000 AXNT20 KNHC 281027 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT TUE OCT 28 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. ...TROPICAL WAVES... A TROPICAL WAVE IS OVER THE EASTERN ATLC WITH AXIS EXTENDING FROM 16N23W TO 8N24W...MOVING W AT 15-20 KT. THE HOVMOLLER OF METEOSAT SATELLITE IMAGERY SHOW A VERY WEAK SIGNAL OF THIS WAVE. SSMI TPW AND GOES-R AIRMASS IMAGERY DEPICT THE WAVE IS IN A DRY MIDDLE TO LOWER LEVEL ENVIRONMENT THAT ALONG DEEP LAYER ENVIRONMENTAL SHEAR HINDER THE DEVELOPMENT OF CONVECTION. MODEL GUIDANCE INDICATES THE WAVE WILL CONTINUE IN A SIMILAR ENVIRONMENT FOR THE NEXT DAY OR SO...THUS ACTING TO VANISH THE WAVE. A TROPICAL WAVE IS MOVING ACROSS THE LESSER ANTILLES WITH AXIS EXTENDING FROM 20N59W TO 10N62W...MOVING W AT 15-20 KT. SSMI TPW AND WATER VAPOR IMAGERY INDICATE THE WAVE IS EMBEDDED IN A MODERATE TO HIGH DEEP LAYER MOIST ENVIRONMENT THAT ALONG A DIFFLUENT ENVIRONMENT ALOFT SUSTAIN SCATTERED MODERATE CONVECTION FROM 12N-20N BETWEEN 52W-62W. A THIRD TROPICAL WAVE IS OVER THE EASTERN CARIBBEAN WITH AXIS EXTENDING FROM 17N66W TO 10N67W...MOVING W AT 15 KT. SSMI TPW AND WATER VAPOR IMAGERY INDICATE THE WAVE IS IN A ZONE OF DEEP LAYER DRY AIR THAT IS KEEPING THE WAVE DEVOID OF CONVECTION. MODEL GUIDANCE INDICATE THE WAVE WILL VANISH IN THE NEXT DAY OR SO. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 9N13W AND CONTINUES TO 7N16W. THE ITCZ BEGINS NEAR 7N16W AND CONTINUES ALONG 7N33W TO 5N47W. BESIDES THE CONVECTION MENTIONED IN THE TROPICAL WAVES SECTION...SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-10N BETWEEN 22W- 42W. SCATTERED MODERATE CONVECTION IS FROM 3N-10N E OF 21W. ...DISCUSSION... GULF OF MEXICO... A BROAD UPPER-LEVEL RIDGE CONTINUES OVER THE BASIN EXTENDING AN AXIS NORTHWARD ACROSS THE EASTERN CONUS...THUS SUPPORTING SURFACE RIDGING IN THE GULF BEING ANCHORED BY A 1022 MB HIGH OVER THE WESTERN ATLC NEAR 31N72W AND A 1020 MB HIGH OVER THE NE GULF NEAR 29N83W. DEEP LAYER DRY AIR REMAINS ACROSS THE ENTIRE BASIN...WHICH SUSTAINS FAIR WEATHER. WINDS ARE FROM THE S-SE IN THE RANGE OF 5-15 KT. SURFACE RIDGING WILL DOMINATE OVER THE GULF THROUGH WED NIGHT WHEN A COLD FRONT WILL ENTER AND EXTEND ACROSS THE NORTHERN BASIN. CARIBBEAN SEA... THE REMNANTS OF FORMER TROPICAL DEPRESSION HANNA CONTINUE TO SUPPORT HEAVY SHOWERS AND ISOLATED TSTMS OVER HONDURAS...NORTHERN NICARAGUA AS WELL AS THE YUCATAN BASIN S OF 20N W OF 80W. FARTHER EAST...A PRE-FRONTAL SURFACE TROUGH EXTENDS FROM THE SW N ATLC WATERS SW TO CENTRAL DOMINICAN REPUBLIC NEAR 18N70W. LOW-LEVEL MOISTURE CONVERGENCE ALONG THE TROUGH AS WELL AS A DIFFLUENT ENVIRONMENT AT THE UPPER-LEVELS SUPPORT SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 100 NM EITHER SIDE OF THE TROUGH AXIS. A TROPICAL WAVE IS MOVING OVER THE EASTERN CARIBBEAN WATERS JUST S OF PUERTO RICO. THIS WAVE IS BEING SUPPORTED BY AN INVERTED MIDDLE-LEVEL TROUGH...HOWEVER DEEP LAYER DRY AIR IN THIS REGION OF THE BASIN IS HINDERING THE DEVELOPMENT OF CONVECTION. A SECOND TROPICAL WAVE IS MOVING OVER THE LESSER ANTILLES. THIS WAVE IS EMBEDDED IN A DEEP MOIST ENVIRONMENT AS WELL AS IN A REGION OF DIFFLUENT FLOW ALOFT THAT ENHANCES SCATTERED SHOWERS AND TSTMS OVER THE FAR EASTERN BASIN E OF 62W...INCLUDING PORTIONS OF THE LEEWARD AND WINDWARD ISLANDS. SEE TROPICAL WAVES SECTIONS ABOVE FOR MORE DETAILS. OTHERWISE...THE WESTERNMOST TROPICAL WAVE IS EXPECTED TO DISSIPATE WEDNESDAY NIGHT. THE NORTHERN PORTION OF THE TRAILING TROPICAL WAVE IS FORECAST TO TRANSITION INTO A TROUGH OF LOW PRESSURE TO MOVE ACROSS PUERTO RICO WED NIGHT INTO THU MORNING. HISPANIOLA... A PRE-FRONTAL SURFACE TROUGH EXTENDS FROM THE SW N ATLC WATERS SW TO CENTRAL DOMINICAN REPUBLIC NEAR 18N70W. LOW-LEVEL MOISTURE CONVERGENCE ALONG THE TROUGH AXIS AS WELL AS A DIFFLUENT ENVIRONMENT AT THE UPPER-LEVELS SUPPORT SCATTERED SHOWERS AND ISOLATED TSTMS WITHIN 100 NM EITHER SIDE OF THE AXIS. ISOLATED SHOWERS ARE POSSIBLE ACROSS THE REMAINDER ISLAND AS THE TROUGH SLOWLY DRIFT EASTWARD AND DISSIPATE LATER TODAY. SHOWER ACTIVITY ASSOCIATED WITH THE REMNANTS OF THE TROUGH IS EXPECTED THROUGH WED NIGHT/THU MORNING. ATLANTIC OCEAN... AN UPPER LEVEL TROUGH IS OVER THE WESTERN ATLC WITH A BASE EXTENDING TO NORTHERN HISPANIOLA. THIS TROUGH ALOFT SUPPORTS A FRONTAL SYSTEM ANALYZED AS A STATIONARY FRONT FROM 30N56W SW TO 27N65W TO 26N75W AND A PRE-FRONTAL SURFACE TROUGH ALONG 27N61W TO CENTRAL DOMINICAN REPUBLIC NEAR 18N70W. SCATTERED SHOWERS ARE WITHIN 100 NM EITHER SIDE OF THE TROUGH AXIS. SURFACE HIGH PRESSURE DOMINATES ELSEWHERE IN THE ATLC N OF 20N BEING ANCHORED BY A 1022 MB HIGH IN THE SW N ATLC NEAR 31N72W AND A 1021 MB HIGH OVER THE CENTRAL ATLC NEAR 28N40W. OTHERWISE...SEE THE TROPICAL WAVES SECTION. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR