000 AXNT20 KNHC 032350 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 705 PM EST MON DEC 03 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS OVER MUCH OF AFRICA BETWEEN 7N AND 10N THEN BECOMES THE ITCZ AT THE WEST COAST OF AFRICA IN SIERRA LEONE NEAR 8N13W. THE ITCZ CONTINUES ACROSS THE TROPICAL ATLC ALONG 5N25W 6N40W TO 10N50W. A SURFACE TROUGH IS EMBEDDED WITHIN THE ITCZ ALONG 15N50W TO 9N52W. SCATTERED MODERATE CONVECTION IS NOTED FROM 7N TO 9N BETWEEN 48W-50W. ...DISCUSSION... GULF OF MEXICO... A SURFACE RIDGE DOMINATES THE GULF ANCHORED BY A 1027 MB HIGH JUST OFF THE COAST OF NORTH CAROLINA NEAR WILMINGTON AND A 1026 MB HIGH OVER GEORGIA BETWEEN SAVANNAH AND AUGUSTA. AT THE UPPER LEVELS NEAR ZONAL DRY WESTERLY FLOW PREVAILS WITH THE EXCEPTION OF A PATCH OF DEEP LAYERED MOISTURE OVER THE NW GULF N OF 26N W OF 90W. RETURN FLOW OVER THE NW GULF IS ENHANCING A LINE OF SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 45 NM OF THE COAST OF LOUISIANA NEAR LAKE CHARLES THROUGH 28.5N94W TO 27N94W. CONVERGENT EASTERLY WINDS OVER THE SE GULF ARE GENERATING A PATCH OF LOW CLOUDS WITH SCATTERED EMBEDDED SHOWERS FROM 23N-25N BETWEEN 84W-88W. THE REMAINDER OF THE GULF IS UNDER MOSTLY CLEAR SKIES. THE SURFACE RIDGE WILL GRADUALLY SHIFT E THROUGH TUE AS A WEAK FRONT MOVES INTO THE NW GULF EARLY WED. CARIBBEAN SEA... MAINLY DRY ZONAL WESTERLY FLOW ALOFT COVERS THE CARIBBEAN AROUND A BROAD UPPER RIDGE LOCATED OVER VENEZUELA. AT THE SURFACE MOSTLY FAIR WEATHER DOMINATES WITH THE EXCEPTION OF A FEW AREAS OF OROGRAPHICALLY ENHANCED SHOWERS ALONG THE COAST OF HONDURAS... NICARAGUA AND BELIZE. ADDITIONAL AREAS OF SHOWER ACTIVITY WERE LOCATED NEAR JAMAICA...HISPANIOLA AND PUERTO RICO. 1400 AND 1540 UTC ASCAT PASSES INDICATED NE WINDS OF 20 KT ACROSS THE NW CARIBBEAN AND JUST S OF OF THE DOMINICAN REPUBLIC. LIGHTER WINDS COVER THE REMAINDER OF THE CENTRAL AND EASTERN CARIBBEAN EXCEPT FOR AN AREA OF 15-20 KT S OF EASTERN HISPANIOLA CAUSING ISOLATED SHOWERS FROM 14N-17N BETWEEN 64W-73W. LITTLE CHANGES ARE EXPECTED OVER THE NEXT 24-48 HOURS. ATLANTIC OCEAN... A SURFACE RIDGE DOMINATES MOST OF THE W ATLC ANCHORED BY A 1027 MB HIGH JUST OFF THE COAST OF NORTH CAROLINA NEAR WILMINGTON AND A 1026 MB HIGH OVER GEORGIA BETWEEN SAVANNAH AND AUGUSTA. THESE SURFACE FEATURES PROVIDED FAIR CONDITIONS ACROSS MUCH OF THE SW NORTH ATLANTIC. TO THE EAST...A SHORTWAVE UPPER TROUGH ALONG 58W IS PROVIDING A LARGE AREA OF DIFLUENT FLOW OVER THE CENTRAL ATLANTIC FROM 20N THROUGH 32N BETWEEN 38W AND 55W. THE DIFLUENT FLOW ALOFT COUPLED WITH A 90-100 KT SUBTROPICAL JET CORE WAS RESULTING A LARGE AREA OF MULTILAYERED CLOUDINESS WITH EMBEDDED SHOWERS. ADDITIONALLY THIS TROUGH WAS PROVIDING SUPPORT FOR A SURFACE TROUGH ALONG 26N55W TO 20N60W WITH AN ASSOCIATED 1010 MB LOW NEAR 21N58W. ISOLATED SHOWERS ARE ALSO N OF HISPANIOLA AND PUERTO RICO WHERE 20-25 KT TRADE WINDS ARE BANKING AGAINST THE COAST. AN UPPER LEVEL RIDGE COVERS THE REMAINDER OF THE CENTRAL ATLANTIC ALONG 43W FEEDING INTO A LARGER UPPER RIDGE OVER THE NE ATLANTIC. THIS UPPER RIDGE SUPPORTS A 1034 MB HIGH E OF THE AZORES NEAR 37N17W. THIS HIGH IS PROVIDING FAIR CONDITIONS ACROSS MOST OF THE E ATLANTIC. AN UPPER LEVEL TROUGH EAST OF THE RIDGE EXTENDS FROM NW AFRICA TO THE CANARY AND CAPE VERDE ISLANDS. THE UPPER TROUGH IS PRODUCING SCATTERED LOW-TOPPED SHOWERS FROM 9N-14N BETWEEN 20W-32W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ COBB