000 AXNT20 KNHC 261051 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SAT OCT 26 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1015 UTC. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM 05N44W TO 13N40W MOVING W AT 15-20 KT. THE WAVE REMAINS EMBEDDED WITHIN LOW-LEVEL TROUGHING AND A DEEP MOISTURE MAXIMUM FROM 06N-14N BETWEEN 38W-44W AS NOTED ON TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION FROM 05N-12N BETWEEN 34W-45W. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 16N17W TO 07N21W TO 05N30W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 05N30W TO 04N34W TO 07N41W TO 03N51W. SCATTERED MODERATE CONVECTION IS FROM 03N-13N BETWEEN 19W-34W. ...DISCUSSION... GULF OF MEXICO... WEST-SOUTHWESTERLY UPPER LEVEL FLOW DOMINATES ACROSS THE GULF THIS MORNING AS WATER VAPOR IMAGERY SHOWS A BROAD MIDDLE TO UPPER LEVEL TROUGH EXITING EASTWARD OFF THE EASTERN U.S. SEABOARD. THE TROUGHING SUPPORTED A STATIONARY FRONT WHICH HAS DISSIPATING IN THE PAST 6 HOURS ACROSS PORTIONS OF THE GULF. WHILE OVERALL SURFACE RIDGING ANCHORED OVER THE SE CONUS IS PROVIDING BRISK E-NE WINDS...MIDDLE TO UPPER LEVEL MOISTURE AND CLOUDINESS WITH POSSIBLE EMBEDDED ISOLATED SHOWERS IS NOTED S OF 25N...AND IN THE VICINITY OF A SURFACE TROUGH ANALYZED FROM 17N92W TO 22N97W. THE RIDGING IS FORECAST TO DRIFT SOUTH- SOUTHEASTWARD THROUGH EARLY SUNDAY WITH THE CURRENT PRESSURE GRADIENT RELAXING SOMEWHAT WHICH WILL IN TURN DIMINISH E-NE WINDS TO 20 KT OR LESS BY LATE SUNDAY. BY EARLY NEXT WEEK AS THE RIDGING SLIDES INTO THE SW NORTH ATLC...E-SE WINDS ARE EXPECTED TO PREVAIL WITH SOUTHERLY RETURN FLOW NOTED N OF 25N W OF 90W AS AN AREA OF LOW PRESSURE DEVELOPS ACROSS THE CENTRAL PLAINS. CARIBBEAN SEA... AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE GULF OF HONDURAS NEAR 16N86W WHICH IS PROVIDING MUCH OF THE WESTERN CARIBBEAN W OF 75W WITH AN UPPER LEVEL DIFFLUENT ENVIRONMENT THIS MORNING. AT THE SURFACE...CONVERGENT TRADES AND THE PRESENCE OF A SHEAR LINE DRAPED FROM CENTRAL CUBA NEAR 22N79W TO THE COAST OF BELIZE NEAR 17N88W IS GENERATING SCATTERED SHOWERS AND TSTMS N OF 16N W OF 81W. ANOTHER AREA OF STRONGER TSTMS IS FOCUSED IN THE VICINITY OF AND ALONG A SURFACE TROUGH ANALYZED FROM 11N80W TO 16N85W WITH CONVECTION MAINLY OCCURRING WITHIN 120 NM EITHER SIDE OF THE TROUGH AXIS... INCLUDING INLAND PORTIONS OF NICARAGUA AND EASTERN HONDURAS. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED NEAR 15N70W AND ALONG WITH BROAD FRONTAL TROUGHING TO THE NORTH ACROSS THE SW NORTH ATLC IS PROVIDING FOR ISOLATED SHOWERS AND TSTMS N OF 15N BETWEEN 70W-78W. FINALLY...MOIST SOUTHWESTERLY UPPER LEVEL FLOW IS NOTED ON WATER VAPOR IMAGERY E OF 70W WITH STRONG DIFFLUENCE NOTED OVER THE WINDWARD ISLANDS AND SE CARIBBEAN. A SURFACE TROUGH IS ANALYZED ALONG 63W WEST OF THE WINDWARD ISLANDS AND IS PROVIDING FOCUS FOR SCATTERED SHOWERS AND ISOLATED TSTMS FROM 10N-16N BETWEEN 59W-66W. HISPANIOLA... CURRENTLY AN UPPER LEVEL LOW IS CENTERED SOUTH OF THE ISLAND NEAR 15N70W THAT CONTINUES TO ADVECT MOISTURE NORTHWARD WITH ENHANCED CLOUDINESS AND ISOLATED SHOWERS NOTED IN THE ADJACENT COASTAL WATERS N OF 15N BETWEEN 70W-76W. MOST OF THE DYNAMIC LIFT IS GENERATED BY THE UPPER LEVEL LOW...HOWEVER TO THE NORTH...A FRONTAL TROUGH REMAINS NEARLY STATIONARY ACROSS THE SW NORTH ATLC WITH SHOWER AND TSTM ACTIVITY REMAINING MOSTLY N OF 20N AT THIS TIME. WHILE THE MORNING PERIOD REMAINS RELATIVELY QUIET...WITH PEAK DAYTIME HEATING AND INSTABILITY...SCATTERED SHOWERS AND TSTMS ARE EXPECTED ACROSS HISPANIOLA SUNDAY AFTERNOON AND EVENING. ATLANTIC OCEAN... A BROAD MIDDLE TO UPPER LEVEL TROUGH IS NOTED ON WATER VAPOR IMAGERY OFFSHORE OF THE EASTERN U.S. SEABOARD WITH AXIS EXTENDING FROM 42N61W TO 34N70W. THE TROUGH SUPPORTS A STATIONARY FRONT ANALYZED FROM 32N60W SW TO 26N70W TO CENTRAL CUBA NEAR 22N78W. A PRE-FRONTAL TROUGH IS ALSO NOTED FROM WESTERN HISPANIOLA NEAR 19N73W TO 26N67W. WITH LOW-LEVEL MOISTURE CONVERGENCE OCCURRING IN CLOSE PROXIMITY OF THE FRONT...AND MIDDLE TO UPPER LEVEL DIFFLUENCE MAXIMIZED EAST AND SOUTH OF THE TROUGH AXIS...SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING ACROSS A LARGE AREA OF THE SW NORTH ATLC THIS MORNING. THIS CONVECTION LIES WITHIN 210 NM EITHER SIDE OF A LINE FROM 32N62W TO 26N67W TO 22N77W. OTHERWISE...THE NORTHWEST PORTION CONTINUES TO DRY OUT DUE TO SURFACE RIDGING BUILDING IN ACROSS THE SE CONUS. FARTHER EAST...AN UPPER LEVEL LOW IS CENTERED NEAR 24N57W AND CONTINUES TO PRODUCE LITTLE SENSIBLE WEATHER AT THE SURFACE. GENERALLY THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED BY A 1026 MB HIGH CENTERED NEAR 33N34W. THE ONLY WEAKNESS NOTED IN THE RIDGING IS A 1019 MB LOW CENTERED NEAR 33N44W AND A SURFACE TROUGH AXIS ANALYZED FROM THE LOW CENTER S- SW TO 30N46W. ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE TROUGH AXIS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN