000 AXNT20 KNHC 160557 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 9N14W 9N39W 8N41W 7N48W 8N50W 7N59W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 4N-9N BETWEEN 18W-30W. A SURFACE TROUGH IS ANALYZED ALONG 40W FROM 5N-12N WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION OCCURRING FROM 2N-12N BETWEEN 31W-44W MAINLY E OF THE SURFACE TROUGH. ANOTHER SURFACE TROUGH IS ALONG 48W FROM 6N-12N WITH NO DEEP CONVECTION IN THE VICINITY DUE TO STRONG SUBSIDENCE ALOFT. ...DISCUSSION... GULF OF MEXICO... A SURFACE RIDGE EXTENDS ACROSS THE FLORIDA PENINSULA AND GULF OF MEXICO ANCHORED BY A 1017 MB HIGH CENTERED IN THE NE GULF NEAR 28N86W. THE RIDGE IS PROVIDING GENERALLY FAIR WEATHER ACROSS THE BASIN WITH A RECENT SCATTEROMETER PASS CAPTURING LIGHT ANTICYCLONIC SURFACE FLOW AROUND THE RIDGE WITH STRONGER SE WINDS UP TO 20 KT OVER THE NW GULF WATERS. ALOFT...AN UPPER LEVEL RIDGE EXTENDS FROM THE NW CARIBBEAN ACROSS CUBA AND OVER THE FLORIDA PENINSULA TO THE MID-ATLC STATES. STRONG SUBSIDENCE AND DRY AIR REMAINS ACROSS THE BASIN E OF 95W AS NOTED IN WATER VAPOR IMAGERY. AS THE SURFACE RIDGE GRADUALLY WEAKENS AND DRIFTS TO THE NE...SLY RETURN FLOW IS FORECAST TO INCREASE ACROSS THE WRN GULF AHEAD OF THE NEXT COLD FRONT TO MOVE OFF THE TEXAS COAST MONDAY AFTERNOON WITH STRONG NLY WINDS FOLLOWING BEHIND THE FRONT. CARIBBEAN SEA... MUCH OF THE CARIBBEAN IS EXPERIENCING GENERALLY FAIR WEATHER UNDER THE INFLUENCE OF DRY AIR AND SUBSIDENCE ASSOCIATED WITH AN UPPER LEVEL RIDGE COVERING THE NW CARIBBEAN N OF 12N W OF 70W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE IN THE SW CARIBBEAN S OF 12N 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 INTO THE EASTERN CARIBBEAN E OF 70W TO NEAR 11N68W. UPPER LEVEL DIFFLUENCE E OF THE UPPER LEVEL TROUGH AXIS AND AN UPPER LEVEL RIDGE TO THE E IS SUPPORTING ISOLATED SHOWERS AND TSTMS N OF 17N BETWEEN 63W-70W. ATLANTIC OCEAN... A 1005 MB LOW IS CENTERED IN THE W ATLC NEAR 30N66W. A SURFACE TROUGH EXTENDS E OF THE LOW CENTER FROM 30N64W ALONG 25N64W TO THE MONA PASSAGE NEAR 18N68W. LOW-LEVEL CONVERGENCE NEAR THE SURFACE TROUGH IS GENERATING SCATTERED SHOWERS AND TSTMS FROM 18N-32N BETWEEN 59W-67W. THE SYSTEM IS SUPPORTED ALOFT BY AN UPPER LEVEL LOW CENTERED NEAR 28N66W WITH TROUGHING EXTENDING S ACROSS THE LESSER ANTILLES AND EASTERN CARIBBEAN. UPPER LEVEL DIFFLUENCE LOCATED E OF THE UPPER TROUGH AXIS IS ALSO ENHANCING THE LARGE AREA OF CONVECTION MENTIONED ABOVE. FARTHER EAST...A 1012 MB LOW IS OVER THE ERN ATLC CENTERED NEAR 26N25W. A COLD FRONT EXTENDS FROM THE LOW CENTER SW TO 23N37W THEN WNW TO 27N49W BECOMING STATIONARY TO BEYOND 32N56W. SCATTERED SHOWERS ARE OCCURRING WITHIN 90 NM EITHER SIDE OF THE FRONTAL BOUNDARY. NE OF THE LOW CENTER A COLD FRONT EXTENDS TO BEYOND 32N19W WITH ISOLATED SHOWERS AND TSTMS WITHIN 120 NM EITHER SIDE OF THE FRONT. THIS LOW AND FRONTAL BOUNDARIES ARE SUPPORTED ALOFT BY A LONGWAVE UPPER LEVEL TROUGH EXTENDING FROM THE NE ATLC ACROSS THE AZORES DIPPING TO NEAR 26N30W. IN THE TROPICS...A SHORTWAVE UPPER LEVEL TROUGH EXTENDS FROM 20N35W TO 17N46W AND IS SHEARING MOISTURE FROM THE ITCZ TO THE E-NE SUPPORTING THE CONVECTION ASSOCIATED WITH THE ITCZ. $$ HUFFMAN