000 AXNT20 KNHC 161142 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST MON NOV 16 2009 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1115 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 7N12W 6N25W 7N41W 6N45W 5N56W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 4N-9N BETWEEN 12W-30W. A SURFACE TROUGH IS ANALYZED ALONG 43W FROM 5N-13N WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION OCCURRING MAINLY E OF THE SURFACE TROUGH FROM 2N-12N BETWEEN 32W-44W. ...DISCUSSION... GULF OF MEXICO... A SURFACE RIDGE EXTENDS ACROSS THE FLORIDA PENINSULA AND GULF OF MEXICO ANCHORED BY A 1019 MB HIGH CENTERED IN THE NE GULF NEAR 27N87W. THE RIDGE IS PROVIDING GENERALLY FAIR WEATHER ACROSS THE BASIN WITH A RECENT SCATTEROMETER PASS AND REGIONAL MODEL DATA DEPICTING LIGHT ANTICYCLONIC SURFACE FLOW AROUND THE RIDGE WITH STRONGER SE WINDS UP TO 15 KT OVER THE NW GULF WATERS. ALOFT... AN UPPER LEVEL RIDGE EXTENDS FROM THE NW CARIBBEAN ACROSS CUBA AND OVER THE FLORIDA PENINSULA ALONG THE EASTERN U.S. SEABOARD TO THE MID-ATLC STATES. STRONG SUBSIDENCE AND DRY AIR REMAINS ACROSS THE BASIN E OF 90W AS NOTED IN WATER VAPOR IMAGERY. AS THE SURFACE RIDGE GRADUALLY WEAKENS AND DRIFTS TO THE NE...SLY RETURN FLOW IS FORECAST TO SHIFT SWLY ACROSS THE WESTERN GULF AHEAD OF THE NEXT COLD FRONT TO MOVE OFF THE TEXAS COAST LATER THIS AFTERNOON WITH STRONG NLY WINDS FOLLOWING BEHIND THE FRONT. CARIBBEAN SEA... MUCH OF THE CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER AS THE INFLUENCE OF DRY AIR AND SUBSIDENCE ASSOCIATED WITH AN UPPER LEVEL RIDGE COVERING THE NW CARIBBEAN N OF 11N W OF 70W REMAINS IN PLACE. SCATTERED SHOWERS AND ISOLATED TSTMS ARE IN THE SW CARIBBEAN S OF 11N BETWEEN 77W-85W AFFECTING PORTIONS OF COSTA RICA AND PANAMA. FARTHER EAST...AN UPPER LEVEL TROUGH EXTENDS FROM THE W ATLC ACROSS PUERTO RICO AND THE EASTERN CARIBBEAN E OF 70W TO OVER NW VENEZUELA. AT THE SURFACE...A SURFACE TROUGH IS ANALYZED FROM THE W ATLC N OF PUERTO RICO FROM 21N66W TO CENTRAL HISPANIOLA NEAR 19N71W. LOW-LEVEL CONVERGENCE NEAR THE SURFACE TROUGH IS GENERATING SCATTERED SHOWERS AND TSTMS SE OF THE BOUNDARY ACROSS THE NE CARIBBEAN N OF 16N E OF 70W. THE MOST CONCENTRATED AREA OF CONVECTION IS OCCURRING OVER PUERTO RICO AND THE US/UK VIRGIN ISLANDS THIS MORNING. AN UPPER LEVEL DIFFLUENT ENVIRONMENT E OF THE UPPER LEVEL TROUGH AXIS IS AIDING TO SUPPORT THIS CONVECTION. ATLANTIC OCEAN... A 1007 MB LOW IS CENTERED IN THE W ATLC NEAR 30N66W. A PRIMARY SURFACE TROUGH EXTENDS E OF THE LOW CENTER FROM 30N62W ALONG 25N62W 20N67W TO CENTRAL HISPANIOLA. LOW-LEVEL CONVERGENCE NEAR THE SURFACE TROUGH IS GENERATING SCATTERED SHOWERS AND TSTMS FROM 18N-32N BETWEEN 55W-66W. THE SYSTEM IS SUPPORTED ALOFT BY AN UPPER LEVEL LOW CENTERED NEAR 27N65W WITH TROUGHING EXTENDING SOUTHWARD ACROSS THE LESSER ANTILLES AND EASTERN CARIBBEAN. UPPER LEVEL DIFFLUENCE LOCATED E OF THE UPPER TROUGH AXIS IS CONTINUING TO ENHANCE THE LARGE AREA OF CONVECTION MENTIONED ABOVE. A SECONDARY SURFACE TROUGH IS ANALYZED W OF THE MORE ACTIVE BOUNDARY FROM 28N64W TO 24N67W AND THEN TO THE SE BAHAMAS. ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE SURFACE TROUGH. FARTHER EAST ACROSS THE CENTRAL AND EASTERN ATLC...A COLD FRONT ENTERS THE DISCUSSION AREA NEAR 32N17W EXTENDING SW ALONG 24N26W TO 23N42W THEN BECOMING STATIONARY ALONG 27N50W TO BEYOND 32N53W. SCATTERED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE FRONTAL BOUNDARY W OF 29W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE FRONT E OF 29W. THIS FRONTAL BOUNDARY IS SUPPORTED ALOFT BY A UPPER LEVEL TROUGH EXTENDING FROM THE NE ATLC WITH TROUGH AXIS EXTENDING FROM E OF THE AZORES NEAR 38N21W DIPPING S-SW ALONG 30N24W TO 20N37W. IN THE TROPICS...AN UPPER LEVEL SHORTWAVE TROUGH EXTENDS FROM 20N37W TO 16N46W AND CONTINUES TO SHEAR MOISTURE EAST-NORTHEASTWARD FROM THE ITCZ FURTHER SUPPORTING THE CONVECTION ASSOCIATED WITH THE ITCZ. $$ HUFFMAN