000 AXNT20 KNHC 031743 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SAT DEC 03 2011 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1735 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH REMAINS INLAND ACROSS AFRICA. THE STARTS TO DEVELOP INLAND OVER LIBERIA AND ENTERS THE ERN TROPICAL ATLC ACROSS SIERRA LEONE NEAR 8N13W CONTINUING WSW ALONG 6N20W 4N30W TO 3N37W. CLUSTERS OF SCATTERED WEAK CONVECTION ARE WITHIN 100-150 NM ON EITHER SIDE OF THE ITCZ BETWEEN 18W-34W. ...DISCUSSION... GULF OF MEXICO... CLUSTERS OF LOW TOP SCATTERED SHOWERS ARE OBSERVED ACROSS THE DISCUSSION AREA ON INFRA-RED IMAGERY THIS LATE MORNING. THESE GROUP OF SHOWERS ARE MOVING WITH THE ANTICYCLONIC FLOW AROUND A SURFACE RIDGE COVERING THE ERN AND SE CONUS. THE SURFACE PRESSURE GRADIENT HAS BECOME TIGHTER OVER THE PAST 12 HOURS OVER THE NW BASIN...ALLOWING FOR AN INCREASING RETURN FLOW UP TO 25 KT N OF 25N W OF 87W. LOOKING AT WATER VAPOR IMAGERY...AN UPPER RIDGE MOVES ACROSS THE GULF WITH DRY STABLE AIR ALOFT AND STRONG SUBSIDENCE OVER THE AREA. RIGHT BEHIND THIS FEATURE THERE IS AN UPPER LEVEL LONGWAVE/TROUGH MOVING ACROSS NRN MEXICO WITH A 110+ KT JET-STREAK DEPICTED ON MODEL DATA AND UPPER LEVEL SATELLITE DERIVED WINDS. THIS SYSTEM WILL BE OUR NEXT WEATHER PRODUCER OVER THE NEXT SEVERAL DAYS...AS THE SURFACE RIDGE SHIFTS EAST INTO THE WRN ATLC...IN ADVANCE OF THE NEXT COLD FRONT EXPECTED TO MOVE INTO THE NW GULF ON MONDAY BRINGING GUSTY NORTHERLY WINDS TO THIS REGION. CARIBBEAN SEA... CLUSTERS OF SCATTERED WEAK SCATTERED SHOWERS ARE MOVING SOUTHWESTERLY W OF 74W. THESE GROUP OF SHOWERS ARE SUPPRESSED BY A BROAD UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER THE WEST COAST OF GUATEMALA AND A SHARP UPPER TROUGH EXTENDING S ACROSS THE WRN ATLC IN TO THE NORTH CENTRAL CARIBBEAN...BOTH PROVIDING DRY STABLE AIR ALOFT AND STRONG SUBSIDENCE TO ALMOST THE ENTIRE DISCUSSION AREA...EXCEPT THE FAR SE BASIN...WHERE A NEARLY STATIONARY SURFACE TROUGH IMPACTS THE LESSER ANTILLES AND ADJACENT WATERS WITH SCATTERED SHOWERS AND THUNDERSTORMS S OF 17N E OF 67W. THIS TROUGH EXTENDS ACROSS THE ATLC INTO THE CARIBBEAN ALONG THE ISLAND OF DOMINICA TO THE COASTAL CITY OF CUMANA IN VENEZUELA. RAINFALL TOTAL ESTIMATES OVER THE PAST FEW DAYS HAVE RANGED FROM ONE INCH TO OVER 2 INCHES FOR THESE GROUP OF ISLANDS. DUE TO THE ALREADY SATURATED TERRAIN FROM THE PAST RAINFALL EVENTS AND SHORT RANGE COMPUTER MODELS SUGGESTING THE CONVECTION LINGERING OVER THE NEXT FEW DAYS IN THIS REGION...THE POSSIBILITY FOR INLAND FLOODING IS HIGHLY EXPECTED FOR THE NEXT FEW DAYS...ESPECIALLY OVER THE HIGHER TERRAIN. FINALLY...THE MONSOON TROUGH EXTENDS ACROSS THE SW CARIBBEAN FROM NRN COLOMBIA TO ACROSS COSTA RICA GENERATING ISOLATED SHOWERS WITHIN 70 NM ALONG THE COAST WRN PANAMA AND COSTA RICA. ATLANTIC OCEAN... AN UPPER TROUGH IS MOVING ACROSS THE WRN SUPPORTING A SET OF 2 NEARLY STATIONARY TROUGHS. ONE IS ANALYZED FROM 30N61W TO 22N67W WITH NO CONVECTION. THE SECOND ONE IS SOMEWHAT ASSOCIATED TO A SURFACE LOW N OF THE AREA THAT EXTENDS A FRONTAL SYSTEM INTO OUR AREA AS A SURFACE TROUGH EXTENDING SSW FROM 30N56W 23N60W INTO THE CARIBBEAN BASIN ALONG THE ISLAND OF DOMINICA. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE WITHIN 70 NM ON EITHER SIDE OF THE AXIS. TO THE E OF THIS SURFACE TROUGH...AN UPPER LEVEL CYCLONIC CIRCULATION MOVES WESTWARD ACROSS THE CENTRAL ATLC CENTERED NEAR 28N39W...REFLECTING A WEAK SURFACE TROUGH ANALYZED FROM 30N38W TO 20N40W. DESPITE THE SURFACE CYCLONIC TURNING ALONG THE TROUGH AXIS...THE CONVECTION IS MORE RELATED TO THE MID-UPPER LEVEL LIFTING FROM THE UPPER LOW...GENERATING WEAK ISOLATED SHOWERS FROM 26N-32N BETWEEN 32W-40W. THE REMAINDER OF THE ATLC IS DOMINATED BY THE BROAD SURFACE RIDGE CENTERED NE OF THE AZORES NEAR 38N23W. SURFACE RIDGING WILL BUILD OVER THE WRN ATLC OVER THE NEXT FEW DAYS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA