000 AXNT20 KNHC 240547 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST SAT NOV 24 2012 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM THE AFRICAN COAST NEAR 11N15W TO 09N18W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 09N18W TO 07N33W TO 05N45W TO 06N54W. A WESTWARD MOVING SURFACE TROUGH IS ANALYZED FROM 05N-10N ALONG 56W. SCATTERED MODERATE CONVECTION IS FROM 05N-10N BETWEEN 17W-28W. ISOLATED MODERATE CONVECTION IS FROM 02N-12N BETWEEN 10W-40W...AND FROM 03N-10N BETWEEN 53W-60W. ...DISCUSSION... GULF OF MEXICO... ZONAL WESTERLY FLOW ALOFT COVERS MUCH OF THE GULF OF MEXICO THIS EVENING...HOWEVER A DEEP LAYERED TROUGH IS CENTERED WELL NORTH OF THE AREA OVER THE GREAT LAKES REGION. AN EMBEDDED SHORTWAVE TROUGH CONTINUES TO PUSH SOUTHEASTWARD OVER THE SE CONUS AND GULF COASTAL PLAINS THAT SUPPORT A COLD FRONT ANALYZED FROM MOBILE BAY NEAR 31N88W SW TO THE TEXAS COAST NEAR 28N87W. AND INLAND OVER SOUTHERN TEXAS AND NORTH-CENTRAL MEXICO. LOW-LEVEL MOISTURE CONVERGENCE IN THE VICINITY OF THE FRONT COUPLED WITH MAXIMUM MIDDLE TO UPPER LEVEL DIFFLUENCE N OF 23N BETWEEN 95W-100W IS GENERATING NUMEROUS SHOWERS AND WIDELY SCATTERED TSTMS OVER PORTIONS OF THE NW GULF WATERS N OF 23N BETWEEN 94W-100W. ELSEWHERE OVER THE GULF THIS EVENING HIGH PRESSURE DOMINATES ANCHORED BY A 1024 MB HIGH CENTERED NEAR 28N91W. ANTICYCLONIC SURFACE WINDS IN THE RANGE OF 5 TO 15 KT ARE EXPECTED TO PREVAIL THROUGH THE OVERNIGHT HOURS INTO SATURDAY. AS THE FRONT SLIDES SOUTHEASTWARD ON SATURDAY...NORTHERLY WINDS ARE FORECAST TO INCREASE SLIGHTLY THROUGH EARLY SUNDAY AND GRADUALLY DECREASE BELOW 20 KT LATE SUNDAY INTO MONDAY AS HIGH PRESSURE ONCE AGAIN RE-ESTABLISHES ITSELF OVER THE SE CONUS AND GULF BASIN. CARIBBEAN SEA... MUCH OF THE CARIBBEAN IS UNDER THE INFLUENCE OF AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED SE OF THE WINDWARD ISLANDS NEAR 11N59W. WHILE THIS CENTER IS EAST OF THE BASIN...MOSTLY SOUTHWESTERLY WINDS PREVAIL ALOFT AND AN OVERALL DIFFLUENT ENVIRONMENT IS OVER A GOOD PORTION OF THE CENTRAL CARIBBEAN. THIS IS DUE LARGELY IN PART TO A MIDDLE TO UPPER LEVEL LOW CENTERED OVER THE WESTERN ATLC NEAR 36N61W THAT DIPS TROUGHING TO THE SW AND OVER THE NORTH-CENTRAL PORTION OF THE BASIN. LOW-LEVEL MOISTURE CONVERGENCE IS MAXIMIZED ALONG A SURFACE TROUGH ANALYZED FROM NORTHERN COLOMBIA NEAR 11N73W TO SOUTH- CENTRAL HISPANIOLA NEAR 18N72W THAT CONTINUES TO PROVIDE FOCUS FOR SCATTERED SHOWERS WITHIN 240 NM EITHER SIDE OF A LINE FROM 19N69W TO 09N82W...INCLUDING HISPANIOLA AND PUERTO RICO. OTHERWISE...THE NW CARIBBEAN REMAINS UNDER FAIR CONDITIONS AS SURFACE RIDGING EXTENDS INTO THE REGION FROM THE GULF OF MEXICO AND THE SE CARIBBEAN CONTINUES TO SHOW CLEAR SKIES FOR THE OVERNIGHT HOURS DUE TO A CENTRAL ATLC SURFACE RIDGE AXIS. ATLANTIC OCEAN... A MIDDLE TO UPPER LEVEL LOW IS CENTERED NEAR 36N61W THAT SUPPORTS A PAIR OF COLD FRONTS ANALYZED INTO THE SW NORTH ATLC WATERS. THE EASTERN-MOST COLD FRONT REMAINS IN A DISSIPATING STAGE...HOWEVER HAS THE MOST ACTIVE CONVECTION ASSOCIATED WITH IT AT THIS TIME. THE FRONT EXTENDS FROM 32N55W TO 25N58W TO 19N69W WITH SCATTERED SHOWERS AND ISOLATED TSTMS OCCURRING FROM 22N-32N BETWEEN 43W-58W. THE SECONDARY REINFORCING COLD FRONT IS ANALYZED FROM 32N59W TO 27N62W TO 21N76W WITH VERY LITTLE IF ANY SHOWER ACTIVITY ASSOCIATED WITH IT. HOWEVER...EXAMINING TOTAL PRECIPITABLE WATER IMAGERY IT DOES SHOW A SLIGHTLY DRIER AND MORE STABLE AIRMASS TO THE NW OF THE COLD FRONT. FARTHER EAST...A MIDDLE TO UPPER LEVEL SHORTWAVE TROUGH IS NOTED ON WATER VAPOR IMAGERY NEAR 38N32W THAT SUPPORTS A COLD FRONT ANALYZED FROM 32N22W TO 31N25W THAT BECOMES STATIONARY ALONG 31N TO 38W THEN TO BEYOND 32N40W. A PRE-FRONTAL SURFACE TROUGH ALSO EXTENDS FROM THE MADEIRA ISLANDS NEAR 33N17W TO 27N29W. ISOLATED SHOWERS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE FRONT AND SURFACE TROUGH AXIS. OTHERWISE...THE REMAINDER OF THE CENTRAL AND EASTERN ATLC IS UNDER THE INFLUENCE OF SURFACE RIDGING ANCHORED BY A 1018 MB HIGH CENTERED NEAR 26N43W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ HUFFMAN