000 AXNT20 KNHC 121144 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST TUE NOV 12 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 1115 UTC. ...SPECIAL FEATURES... A GALE WARNING IS FORECAST TO BE IN EFFECT BEGINNING 13/0000 UTC AS A COLD FRONT EMERGES INTO THE NW GULF WATERS AND SWIFTLY PUSHES ACROSS THE GULF OF MEXICO BASIN WITH FREQUENT GALE FORCE GUSTS OF NE WINDS GENERALLY NORTH OF THE COLD FRONT. SEE LATEST HIGH SEAS FORECAST UNDER AWIPS/WMO HEADERS MIAHSFAT2/FZNT02 KNHC FOR MORE DETAILS. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 12N16W TO 09N22W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N22W TO 06N30W TO 06N43W TO 04N49W. A SURFACE TROUGH IS EMBEDDED WITHIN THE AXIS FROM 07N47W TO 12N45W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 04N-09N BETWEEN 13W-29W. ISOLATED MODERATE CONVECTION IS FROM 09N-13N BETWEEN 34W-45W. ...DISCUSSION... GULF OF MEXICO... A MIDDLE TO UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED OVER THE NW CARIBBEAN SEA NEAR 18N80W THAT IS PROVIDING SOUTH- SOUTHWEST TO WESTERLY FLOW ALOFT OVER THE GULF THIS MORNING. UPPER LEVEL DIFFLUENCE BETWEEN THE UPPER LEVEL RIDGE AND AN UPPER LEVEL TROUGH AXIS EXTENDING ALONG 107W CONTINUES TO ADVECT MOISTURE OVER MEXICO AND THEN NORTHEASTWARD OVER A MAJORITY OF THE GULF BASIN. THIS MARGINAL UPPER LEVEL LIFT ALONG WITH LOW- LEVEL MOISTURE CONVERGENCE ALONG A SURFACE TROUGH ANALYZED FROM THE YUCATAN PENINSULA NEAR 21N90W TO 25N89W IS GENERATING WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS GENERALLY S OF 27N BETWEEN 82W-98W. OTHERWISE...EAST-NORTHEAST WINDS IN THE RANGE OF 10 TO 20 KT ARE FORECAST FOR A FEW MORE HOURS AND WILL GRADUALLY INCREASE AS A COLD FRONT FOLLOWED BY REINFORCING SURFACE RIDGING WILL BARREL SOUTHWARD ACROSS THE CENTRAL AND SOUTHERN PLAIN STATES INTRODUCING ANOTHER ROUND OF STRONG NORTH-NORTHEASTERLY WINDS...NOTE SPECIAL FEATURES SECTION ABOVE...TO THE GULF TUESDAY THROUGH LATE THURSDAY. CARIBBEAN SEA... AN UPPER LEVEL ANTICYCLONE IS CENTERED OVER THE NW CARIBBEAN NEAR 18N80W AND INFLUENCES MUCH OF THE CARIBBEAN WITH DRY AIR AND SUBSIDENCE WITH THE EXCEPTION OF THE FAR SW CARIBBEAN AND THE SE CARIBBEAN S OF 14N E OF 67W. WATER VAPOR IMAGERY INDICATES UPPER LEVEL DIFFLUENCE IS MAXIMIZED WEST OF A LINE FROM 13N84W TO 09N76W THAT CONTINUES TO GENERATE WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS IN THE VICINITY OF THE MONSOON TROUGH ANALYZED ALONG 08N/09N. OTHER ISOLATED SHOWERS ARE OCCURRING FARTHER NORTH FROM 14N-20N BETWEEN 80W-89W. THE REMAINDER OF THE CARIBBEAN BASIN IS UNDER THE INFLUENCE OF THE DRY AND STABLE NORTHEASTERLY FLOW ALOFT WITH NO SIGNIFICANT DEEP CONVECTION NOTED ON SATELLITE IMAGERY. HOWEVER...LOW-LEVEL MOISTURE AND ISOLATED LOW-TOPPED SHOWERS CONTINUE TO ADVECT WESTWARD ON BRISK TRADES IN THE RANGE OF 15 TO 25 KT. LASTLY...A WEAK UPPER LEVEL LOW IS CENTERED NEAR 13N67W AND IS PROVIDING FOR INCREASED MOISTURE AND CLOUDINESS TO THE EAST OVER PORTIONS OF THE SE CARIBBEAN AND WINDWARD ISLANDS THIS MORNING. ISOLATED SHOWERS ARE NOTED ON SATELLITE IMAGERY S OF 15N BETWEEN 58W-70W. ...HISPANIOLA... CURRENTLY A FEW ISOLATED LOW-TOPPED SHOWERS ARE OCCURRING ACROSS THE ISLAND AND THIS ACTIVITY IS EXPECTED TO CONTINUE THROUGH THE MORNING HOURS INTO THE DAY ON TUESDAY. OTHERWISE...DRY AND OVERALL STABLE NORTHERLY FLOW ALOFT IS NOTED ON WATER VAPOR IMAGERY WHICH IS ANTICIPATED TO LIMIT ANY SIGNIFICANT DEEP CONVECTION OVER THE NEXT FEW DAYS. ATLANTIC OCEAN... MOSTLY WEST-NORTHWESTERLY FLOW IS NOTED ON WATER VAPOR IMAGERY THIS MORNING OVER THE SW NORTH ATLC WITHIN THE NORTHEASTERN PERIPHERY OF AN UPPER LEVEL ANTICYCLONE CENTERED OVER THE NW CARIBBEAN SEA. WEAK UPPER LEVEL TROUGHING IS NOTED WELL TO THE EAST OVER THE CENTRAL ATLC NEAR 32N58W THAT SUPPORTS PRE-FRONTAL SURFACE TROUGHING BETWEEN GENERALLY N OF 25N BETWEEN 48W-75W. THE COLD FRONT HAS PASSED THROUGH BERMUDA AND EXTENDS FROM 33N60W TO 31N65W. ISOLATED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE FRONT. OTHERWISE THE SURFACE TROUGHS ARE PROMOTING LOW-LEVEL MOISTURE CONVERGENCE WITH WIDELY SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING N OF 25N BETWEEN 49W-75W. THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF SURFACE RIDGING ANCHORED BY A 1034 MB HIGH CENTERED WELL NORTH OF THE DISCUSSION AREA NEAR 46N24W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN