000 AXNT20 KNHC 162354 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT THU OCT 16 2008 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURES... HURRICANE OMAR IS CENTERED NEAR 22.1N 59.7W AT 17/0000 UTC OR ABOUT 305 NM NORTHEAST OF THE NRN LEEWARD ISLANDS MOVING N-NE AT 23 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 985 MB. MAXIMUM SUSTAINED WIND SPEED IS 65 KT WITH GUSTS TO 80 KT. PLEASE SEE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT5/ WTNT35 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT5/WTNT25 KNHC FOR MORE DETAILS. SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 120 NM OF THE CENTER IN THE NE QUADRANT. BANDS OF SCATTERED MODERATE/STRONG CONVECTION REMAIN WELL TO THE E AND SE OF THE CENTER WITHIN 120 NM OF A LINE FROM 25N54W TO 15N63W. SCATTERED SHOWERS COVER THE REMAINDER OF THE ERN CARIBBEAN SEA E OF 74W. OMAR IS FORECAST TO GRADUALLY WEAKEN WHILE TRACKING NE AND BEGIN EXTRATROPICAL TRANSITION BY SUNDAY. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 24W/25W S OF 17N MOVING W NEAR 10-15 KT. WELL-DEFINED CYCLONIC CURVATURE IS EVIDENT ON SATELLITE IMAGERY WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 5N-15N BETWEEN 22W-26W. A TROPICAL WAVE IS ALONG 47W S OF 15N MOVING W NEAR 15 KT. THE WAVE IS OBSERVED ON THE SSMI-TPW PRODUCT FROM CIMSS AND REMAINS EMBEDDED WITHIN THE ITCZ. SCATTERED MODERATE CONVECTION IS FROM 7N-12N BETWEEN 44W-49W. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 9N13W 8N22W 7N26W 6N33W 7N44W 7N49W 9N61W. IN ADDITION TO CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4N-8N BETWEEN 25W-29W. SIMILAR CONVECTION IS FROM 4N-9N BETWEEN 31W-42W. ...DISCUSSION... GULF OF MEXICO... A WEAK UPPER-LEVEL LOW IS LOCATED OVER NE MEXICO NEAR 25N101W. AN UPPER LEVEL RIDGE ANCHORED IN THE CENTRAL GULF NEAR 25N91W COVERS THE ENTIRE GULF AND FLORIDA PANHANDLE. MOIST SLY WIND FLOW IS OVER THE GULF W OF 91W INCLUDING THE WRN BAY OF CAMPECHE. THESE UPPER-LEVEL WINDS...ALONG WITH A COLD FRONT ENTERING THE GULF NEAR PORT ARTHUR TEXAS EXTENDING SE TO BROWNSVILLE AND A PRE-FRONTAL SURFACE TROUGH EXTENDING FROM BROWNSVILLE TO NEAR 20N96W ARE GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS OVER THE WRN GULF W OF 94W AND ACROSS THE BAY OF CAMPECHE. AT THE SURFACE...A 1021 MB HIGH PRESSURE CENTERED OVER THE WRN FLORIDA PANHANDLE CONTROLS THE GULF E OF 91W...INCLUDING THE FLORIDA PENINSULA AND STRAITS OF FLORIDA. STRONG SUBSIDENCE/ DRY AIR IS ALSO NOTED IN THE UPPER-LEVELS E OF 92W IN THE GULF. MODERATE TO STRONG EASTERLY WINDS CONTINUE OVER THE SE GULF THIS EVENING S OF 25N AND E OF 90W. CARIBBEAN SEA... WEAK UPPER TROUGHING EXTENDS FROM A WRN ATLC UPPER LOW CENTERED NORTH OF HISPANIOLA ACROSS THE NRN CARIBBEAN N OF 16N. STRONG SUBSIDENCE/DRY AIR IS ACROSS HISPANIOLA...JAMAICA...CUBA AND THE NRN YUCATAN PENINSULA. AT THE SURFACE...A 1008 MB LOW IS OVER ERN EL SALVADOR NEAR 14N88W WITH SCATTERED SHOWERS AND TSTMS ACROSS MUCH OF CENTRAL AMERICA EXTENDING ACTIVITY INTO WRN CARIBBEAN WATERS FROM 11N-15N BETWEEN 80W-83W. A SURFACE TROUGH EXTENDS FROM OMAR ACROSS THE ERN CARIBBEAN TO NORTH OF THE ABC ISLANDS. SCATTERED SHOWERS AND TSTMS ARE RELATED TO THIS FEATURE E OF 74W. MORE INTENSE CONVECTION THIS EVENING IS CONCENTRATED ACROSS THE LEEWARD ISLANDS N OF 14N. AN UPPER LEVEL RIDGE AXIS EXTENDS FROM THE CENTRAL ATLC ACROSS THE SRN WINDWARD ISLANDS TO NE VENEZUELA AND IS PROVIDING UPPER DIFFLUENCE TO AID IN SUPPORTING THE PRECIPITATION ALONG THE AFOREMENTIONED SURFACE TROUGH. ATLANTIC OCEAN... AN UPPER LEVEL RIDGING EXTENDS ALONG THE ERN US SEABOARD INTO WRN ATLC WATERS AND THE BAHAMAS W OF 70W. STRONG SUBSIDENCE IS ASSOCIATED WITH THIS UPPER RIDGE BRINGING DRY AIR ACROSS THE FLORIDA PENINSULA...THE BAHAMAS AND CUBA. A DEEP LAYERED TROUGH EXTENDING FROM AN UPPER-LEVEL LOW LOCATED NORTH OF THE AREA NEAR 37N57W EXTENDS TO AN UPPER LOW NORTH OF HISPANIOLA NEAR 21N69W. THIS UPPER TROUGH SUPPORTS A SURFACE TROUGH THAT ENTERS THE DISCUSSION AREA NEAR 32N51W SW TO JUST NORTH OF OMAR NEAR 29N53W. A LARGE AREA OF DEEP-LAYERED MOISTURE WITH EMBEDDED SHOWERS IS WITHIN 250 NM ON EITHER SIDE OF THE TROUGH. THE E ATLC IS UNDER THE INFLUENCE OF A SURFACE RIDGE ANCHORED ON A 1029 MB HIGH CENTERED S OF THE AZORES NEAR 36N29W. ALOFT A RIDGE/TROUGH/RIDGE PATTERN IS OBSERVED OVER THE CENTRAL AND E ATLC WITH RIDGES CENTERED NEAR 30N44W AND INLAND OVER W AFRICA. BOTH RIDGES ARE SUPPORTING CONVECTION ALONG THE ITCZ AXIS. $$ HUFFMAN