000 AXNT20 KNHC 170555 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 AM EST TUE NOV 17 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 5N32W 6N44W 5N47W 4N53W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 175 NM EITHER SIDE OF THE AXIS BETWEEN 18W-35W. A SURFACE TROUGH EXTENDS FROM 4N45W TO 12N48W WITH A 1010 MB LOW ALONG THE SURFACE TROUGH NEAR 8N47W. SCATTERED SHOWERS/ISOLATED MODERATE CONVECTION IS FROM 4N-12N BETWEEN 42W-49W. ...DISCUSSION... GULF OF MEXICO... AS OF 0300 UTC...A COLD FRONT EXTENDS INTO THE GULF NEAR BILOXI MISSISSIPPI CONTINUING ALONG 26N93W 21N96W AND INLAND ACROSS EASTERN MEXICO NEAR 20N97W. ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE FRONT. ALOFT...THE COLD FRONT IS SUPPORTED BY AN UPPER LEVEL LOW PROGRESSING ACROSS THE CENTRAL AND SOUTHERN PLAINS WITH A TROUGH AXIS EXTENDING FROM MISSOURI THROUGH TEXAS TO NORTHERN MEXICO. STRONG NLY WINDS ARE OBSERVED BEHIND THE FRONT UP TO 30 KT. THE REMAINDER OF THE GULF IS INFLUENCED BY A WEAKENING SURFACE RIDGE ACROSS THE EASTERN GULF OF MEXICO ANCHORED BY A 1016 MB HIGH CENTERED NEAR 29N87W. THE SURFACE RIDGE IS PROVIDING GENERALLY FAIR WEATHER E OF 87W AND IS ENHANCED BY AN UPPER LEVEL RIDGE THAT EXTENDS FROM THE YUCATAN CHANNEL OVER THE FLORIDA PENINSULA AND INTO THE W ATLC. CARIBBEAN SEA... MUCH OF THE CARIBBEAN SEA W OF 66W IS UNDER THE INFLUENCE OF DRY AND STABLE NW FLOW ALOFT WHICH IS PROVIDING GENERALLY FAIR SKIES AND A LACK OF ANY DEEP CONVECTION. AN UPPER LEVEL RIDGE EXTENDS FROM THE E PACIFIC REGION ACROSS CENTRAL AMERICA NE OVER THE YUCATAN PENINSULA AND FLORIDA PENINSULA AS WELL AS E ALONG 14N TO 66W. A FEW ISOLATED SHOWERS AND TSTMS HOWEVER ARE LOCATED IN THE SW CARIBBEAN S OF 15N BETWEEN 75W-84W DUE IN PART TO UPPER LEVEL DIFFLUENCE. AN UPPER LEVEL TROUGH WITH AXIS FROM THE LEEWARD ISLANDS TO THE ABC ISLANDS AND NW VENEZUELA IS E OF 66W GENERATING SCATTERED SHOWERS NE OF A LINE FROM SAINT LUCIA TO S/CENTRAL HISPANIOLA NEAR 18N71W. THIS SHOWER ACTIVITY SPREADS EAST OF THE LESSER ANTILLES TO 56W IN THE TROPICAL NORTH ATLC. ATLANTIC OCEAN... A SURFACE RIDGE RESIDES ACROSS THE W ATLC W OF 72W AND ACROSS THE FLORIDA PENINSULA INTO THE EASTERN GULF OF MEXICO. GENERALLY NE WINDS UP TO 20 KT ARE OBSERVED ACROSS THE BAHAMAS AND ADJACENT COASTAL WATERS THIS EVENING. FARTHER EAST...A 1008 MB LOW IS CENTERED NEAR 26N66W WITH A SURFACE TROUGH EXTENDING S-SW ALONG 22N67W TO OVER N/CENTRAL HISPANIOLA NEAR 19N71W. THE LOW AND SURFACE TROUGH ARE SUPPORTED ALOFT BY AN UPPER LEVEL LOW CENTERED NEAR 26N66W AND AN ASSOCIATED UPPER LEVEL TROUGH AXIS THAT EXTENDS S-SE TO THE LEEWARD ISLANDS AND ACROSS THE EASTERN CARIBBEAN SEA. LOW-LEVEL CONVERGENCE E OF THE SURFACE TROUGH COUPLED WITH UPPER LEVEL DIFFLUENCE E OF THE UPPER LEVEL TROUGH AXIS IS GENERATING AN AREA OF SCATTERED SHOWERS AND TSTMS COVERING A LARGE SWATH OF THE SW NORTH ATLC AND THE TROPICAL NORTH ATLC FROM 13N-30N BETWEEN 56W-66W. ACROSS THE CENTRAL AND EASTERN ATLC...A BROAD SURFACE RIDGE EXTENDS FROM A 1029 MB HIGH NEAR 35N37W. A COLD FRONT PROTRUDES INTO THE RIDGE ENTERING THE DISCUSSION AREA NEAR 32N11W CONTINUING SW ALONG 25N16W 20N28W THEN W TO 20N40W WHERE IT CONTINUES AS A STATIONARY FRONT TO BEYOND 30N52W. ISOLATED SHOWERS ARE WITHIN 90 NM EITHER SIDE OF THE FRONT E OF 45W. SCATTERED SHOWERS AND TSTMS HOWEVER ARE ASSOCIATED WITH THE STATIONARY FRONT W OF 45W AND COVER THE AREA WITHIN 90 NM EITHER SIDE OF THE FRONT BETWEEN 45W-51W. THIS ACTIVITY IS BEING ENHANCED BY UPPER LEVEL DIFFLUENCE ALOFT DUE TO AN UPPER LEVEL RIDGE OVER THE CENTRAL ATLC WITH AXIS ALONG 48W. THE OVERALL FRONTAL STRUCTURE HOWEVER IS SUPPORTED BY AN UPPER LEVEL TROUGH ACROSS THE EASTERN ATLC WITH AXIS EXTENDING FROM THE MADEIRA ISLANDS SW THROUGH 25N23W TO 15N40W. $$ HUFFMAN