000 AXNT20 KNHC 150535 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST SUN NOV 15 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 8N13W 7N29W 6N32W 7N44W 7N48W 6N57W. WIDELY SCATTERED MODERATE CONVECTION IS FROM 3N-10N BETWEEN 22W-34W NEAR A SURFACE TROUGH THAT IS ANALYZED ALONG 32W FROM 6N-10N. SCATTERED SHOWERS ARE ALSO FOCUSED WITHIN 150 NM EITHER SIDE OF A SURFACE TROUGH THAT IS ANALYZED FROM 13N41W TO 6N46W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS NORTH OF THE SURFACE TROUGH FROM 13N-17N BETWEEN 36W-43W. ...DISCUSSION... GULF OF MEXICO... A SURFACE RIDGE INFLUENCES MOST OF THE GULF ANCHORED BY A 1016 MB HIGH CENTERED IN THE N/CENTRAL GULF NEAR 29N89W. THE RIDGE IS PROVIDING GENERALLY FAIR WEATHER BASIN WIDE THIS EVENING WITH LIGHT SURFACE WINDS E OF 93W. STRONGER SE RETURN FLOW...UP TO 20 KT IS OBSERVED IN SHIP AND BUOY DATA AS WELL AS A RECENT SCATTEROMETER PASS ACROSS THE WRN GULF. ALOFT...AN UPPER LEVEL RIDGE COVERS MUCH OF THE GULF WITH AXIS EXTENDING FROM SOUTHERN MEXICO ACROSS ALONG 90W TO OVER THE SE CONUS AND MID-ATLC STATES. STRONG SUBSIDENCE AND DRY AIR IS NOTED ON WATER VAPOR IMAGERY WHICH EXTENDS FROM EASTERN MEXICO ACROSS THE GULF OF MEXICO INTO THE W ATLC AND ACROSS THE NW CARIBBEAN. THE SURFACE RIDGE IS FORECAST TO DRIFT E-NE AND WEAKEN THROUGH LATE SUNDAY WITH THE SOUTHERLY RETURN FLOW GRADUALLY INCREASING OVER THE WESTERN GULF AHEAD OF THE NEXT COLD FRONT TO MOVE OFF THE TEXAS COAST MONDAY AFTERNOON. CARIBBEAN SEA... THE SURFACE RIDGE INFLUENCING THE GULF OF MEXICO EXTENDS ACROSS CUBA AND THE NW CARIBBEAN SEA AND IS PROVIDING MOSTLY FAIR WEATHER N OF 17N E OF 77W. IT IS SUPPORTED ALOFT BY AN UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OVER EASTERN NICARAGUA NEAR 12N84W AND AN UPPER RIDGE AXIS THAT EXTENDS NORTHWARD ALONG 86W TO THE YUCATAN CHANNEL. FARTHER SOUTH...UPPER LEVEL DIFFLUENCE NEAR THE CORE OF THE UPPER LEVEL HIGH IS ENHANCING SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE SW CARIBBEAN S OF 14N BETWEEN 77W-85W. THE REMAINDER OF THE CARIBBEAN IS INFLUENCED BY UPPER LEVEL TROUGHING THAT EXTENDS FROM AN UPPER LEVEL LOW CENTERED IN THE W ATLC NEAR 33N69W. THE UPPER TROUGH AXIS EXTENDS ACROSS PUERTO RICO THEN W-SW TO NEAR 15N75W. ISOLATED SHOWERS ARE OCCURRING ACROSS HISPANIOLA AND THE NE CARIBBEAN N OF 16N E OF 73W. ATLANTIC OCEAN... A 1004 MB LOW IS CENTERED NEAR 33N71W IN THE W ATLC WITH A SURFACE TROUGH ENTERING THE DISCUSSION AREA NEAR 32N70W AND CONTINUING SOUTHWARD ALONG 26N68W TO 20N69W. MOST OF THE CONVECTIVE ACTIVITY ASSOCIATED WITH THIS LOW IS LOCATED E OF THE SURFACE TROUGH AND LARGELY ENHANCED BY UPPER LEVEL DIFFLUENCE E OF THE SURFACE TROUGH WHICH COINCIDES WITH THE UPPER LEVEL TROUGH AXIS ALONG 66W. SCATTERED SHOWERS AND TSTMS ARE LOCATED IN THE UPPER DIFFLUENT AREA COVERING FROM 19N TO BEYOND 32N BETWEEN 55W-66W. SCATTERED SHOWERS LINGER ACROSS THE TURKS AND CAICOS ISLANDS...HISPANIOLA AND THE WINDWARD PASSAGE BEHIND THE SURFACE TROUGH. FARTHER EAST...A 1012 MB LOW IS CENTERED NEAR 30N32W WITH A COLD FRONT EXTENDING W-SW ALONG 27N40W TO 28N50W TO BEYOND 31N57W. SCATTERED SHOWERS ARE OCCURRING WITHIN 120 NM EITHER SIDE OF THE COLD FRONT. SE OF THIS COLD FRONT...ANOTHER COLD FRONT IS ANALYZED ENTERING THE DISCUSSION AREA NEAR 32N22W AND EXTENDS SW TO 27N33W. SCATTERED SHOWERS AND TSTMS ARE WITHIN 75 NM EITHER SIDE OF THE FRONT. BOTH OF THESE COLD FRONTS ARE SUPPORTED ALOFT BY AN UPPER LEVEL LONGWAVE TROUGH LOCATED ACROSS THE EASTERN NORTH ATLC N OF 26N BETWEEN 20W-45W. FARTHER SOUTH OVER THE TROPICAL ATLC...A SHORTWAVE UPPER LEVEL TROUGH EXTENDS FROM 24N37W TO 10N50W. UPPER LEVEL DIFFLUENCE E OF THE TROUGH AXIS IS SUPPORTING AN AREA OF SCATTERED SHOWERS AND TSTMS FROM 13N-17N BETWEEN 36W-43W. $$ HUFFMAN