000 AXNT20 KNHC 291743 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 PM EST SAT NOV 29 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 5N10W 5N22W 4N40W 7N50W INTO THE GUYANAS. SCATTERED MODERATE CONVECTION IS FROM 1N-6N BETWEEN 22W-36W. ...DISCUSSION... GULF OF MEXICO... A STRONG COLD FRONT HAS ENTERED THE NW CORNER OF THE GULF THIS MORNING. AS OF 1500 UTC...IT EXTENDS FROM SE LOUISIANA TO THE DEEP SOUTH TEXAS. CURRENTLY...THE MOSAIC DOPPLER RADAR FROM THE SE U.S. REVEALS A BAND OF SHOWERS WITH EMBEDDED TSTMS ASSOCIATED WITH THE FRONTAL BOUNDARY WHICH IS ALREADY PRODUCING WIDESPREAD RAINS OVER THE SE CONUS. THIS FEATURE WILL MOVE SE ACROSS THE GULF REGION REACHING SOUTH FLORIDA AND THE YUCATAN PENINSULA SUN NIGHT AND WILL BE OUT OF AREA...OVER WESTERN CUBA AND THE NW CARIBBEAN...MON MORNING. WINDS ARE EXPECTED TO INCREASE JUST BELOW GALE FORCE ON EITHER SIDE OF THE FRONT. IN THE WAKE OF THE FRONT A RELATIVELY COOLER AND DRIER AIR MASS WILL INVADE THE GULF WITH N TO NW SURFACE WINDS. THE REMAINDER OF THE AREA IS UNDER THE INFLUENCE OF A SFC RIDGE ANCHORED ON A 1018 MB HIGH LOCATED OVER THE W ATLC. AS SOUTHERLY RETURN FLOW AROUND THIS SURFACE HIGH DRAWS INCREASED MOISTURE AND INSTABILITY OVER THE GULF REGION...THE THREAT FOR STRONG THUNDERSTORMS WILL EXIST ALONG AND AHEAD OF THE COLD FRONT. THE RISK OF TSTMS IS ALREADY IN THE FORECAST FOR SOUTH FLORIDA SUN AFTERNOON DUE TO INCREASING MOISTURE WITH SWLY WINDS ALOFT. IN THE UPPER LEVELS...A BROAD RIDGE COVERS THE GULF REGION...WITH STRONG UPPER LEVEL WINDS ACROSS THE NORTHERN PERIPHERY OF THE RIDGE OVER THE N GULF STATES/N GULF WATERS. UPPER LEVEL MOISTURE CONTINUES STREAMING ACROSS THE N GULF...WHILE MODERATE TO STRONG SUBSIDENCE IS PRESENT OVER THE S GULF RESULTING IN MOSTLY FAIR WEATHER ACROSS MUCH OF THE AREA. LOOKING AHEAD...THE NEXT COLD FRONT IS FORECAST TO MOVE OFF THE TEXAS COAST ON WED. CARIBBEAN SEA... IN THE SW CARIBBEAN...A STATIONARY 1010 MB SURFACE LOW IS CENTERED N OF PANAMA NEAR 10N79W GENERATING SCATTERED SHOWERS AND ISOLATED TSTMS ACROSS THE SW CARIBBEAN S OF 12N...AND OVER PANAMA AND COASTAL WATERS. THE TAIL END OF AN OLD FRONTAL BOUNDARY...ANALYZED AS A SURFACE TROUGH ACROSS THE TROPICS OVER THE CENTRAL ATLC...IS PRODUCING SCATTERED SHOWERS OVER THE SOUTHERN WINDWARD ISLANDS...MAINLY OVER TRINIDAD AND TOBAGO. PATCHES OF LOW LEVEL MOISTURE EMBEDDED IN THE TRADE WIND FLOW ARE NOTED ACROSS THE REMAINDER OF THE BASIN...MORE CONCENTRATED BETWEEN HONDURAS AND THE CAYMAN ISLANDS...SOUTH OF HAITI AND SW OF PUERTO RICO. SIMILAR CLOUDS ARE NOTED JUST OFFSHORE VENEZUELA...INCLUDING ALSO THE ABC ISLANDS. IN THE UPPER LEVELS...A RIDGE...WITH AXIS FROM N COLOMBIA TO THE YUCATAN PENINSULA...DOMINATES THE WEST AND CENTRAL CARIBBEAN WHILE AN UPPER-LEVEL TROUGH IS JUST EAST OF THE LESSER ANTILLES. THE SURFACE RIDGE N OF THE AREA WILL SHIFT E AND SLIGHTLY STRENGTHEN...ALLOWING TRADEWINDS TO INCREASE ACROSS THE E-CARIBBEAN. ON THE OTHER HAND...SE TO S WINDS WILL ALSO INCREASE OVER THE NW CARIBBEAN BEGINNING ON SUN IN ADVANCE OF A GULF OF MEXICO COLD FRONT EXPECTED TO REACH WESTERN CUBA AND THE NW CARIBBEAN MON MORNING. NW WINDS OF 15-20 KT WILL FOLLOW THE FRONT...KEEPING TEMPERATURES ACROSS CUBA ON THE COOL SIDE. ATLANTIC OCEAN... A RIDGE/TROUGH/RIDGE PATTERN DOMINATES MOST OF THE FORECAST AREA. A SURFACE RIDGE EXTENDS ACROSS THE W ATLC FROM A 1018 MB HIGH LOCATED NEAR 27N68W...MAINTAINING TRANQUIL CONDITIONS. AN UPPER-LEVEL TROUGH LIES ACROSS THE CENTRAL ATLC WHILE A BROAD UPPER-LEVEL RIDGE CENTERED ON A HIGH NEAR 6N27W DOMINATES MOST OF THE EASTERN ATLC AND THE DEEP TROPICS EAST OF 42W. UPPER DIFFLUENCE BETWEEN THESE TWO UPPER-LEVEL FEATURES IS ENHANCING CONVECTION ALONG A SFC TROUGH THAT EXTENDS ALONG 20N38W 14N50W 8N60W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 80 NM NW OF THE TROUGH AXIS BETWEEN 43W AND 54W WITH THE STRONGEST CONVECTIVE ACTIVITY NEAR 14N52W. AN EARLIER QSCAT PASS SHOWED THE PRESENCE OF ANOTHER SFC TROUGH OVER THE CENTRAL ATLC EXTENDING FROM 25N47W TO 21N50W. THIS TROUGH IS PROBABLY ASSOCIATED WITH THE REMNANTS OF AN OLD FRONTAL BOUNDARY PREVIOUSLY RELATED TO THE LOW PRES SYSTEM THAT HAS BEING SPINNING OVER THE CENTRAL ATLANTIC OCEAN FOR SEVERAL DAYS. THIS LOW IS CURRENTLY MERGING WITH A FRONTAL ZONE...AND TROPICAL OR SUBTROPICAL CYCLONE FORMATION IS NOT ANTICIPATED. A LARGE AREA OF STORM FORCE WINDS IS ASSOCIATED WITH THIS LOW LOCATED N OF FORECAST REGION NEAR 38N42W. A SFC RIDGE AXIS EXTENDS FROM THE AZORES TO THE CANARY ISLANDS AND IS DOMINATING THE E ATLC. OF NOTE...NOVEMBER 30 MARKS THE CONCLUSION OF THE 2008 ATLANTIC HURRICANE SEASON. DURING THIS SEASON...SIXTEEN NAMED TROPICAL CYCLONES OCCURRED. OF THESE SIXTEEN...EIGHT WERE HURRICANES...OF WHICH FIVE WERE MAJOR HURRICANES OF SAFFIR-SIMPSON CATEGORY THREE STRENGTH OF STRONGER. THIS SEASON WAS THE FIRST EVER WHEN SIX CONSECUTIVE TROPICAL CYCLONES MADE LANDFALL ON THE CONUS MAINLAND. OVERALL...THE 2008 HURRICANE SEASON IS TIED AS THE FOURTH MOST ACTIVE IN TERMS OF NUMBER OF NAMED STORMS AND MAJOR HURRICANES...AND IS ALSO TIED AS FIFTH MOST ACTIVE IN TERMS OF NUMBER OF HURRICANES SINCE 1944...THE BEGINNING OF THE AERIAL RECONNAISSANCE ERA. FINALLY...THIS IS THE TENTH SEASON TO PRODUCE ABOVE-NORMAL TROPICAL CYCLONE ACTIVITY SINCE 1995 WHEN THE CURRENT ACTIVE HURRICANE ERA BEGAN. ADDITIONALLY...A TOTAL OF 64 TROPICAL WAVES MOVED OFF THE COAST OF AFRICA THIS SEASON WHICH IS NEAR THE SEASONAL AVERAGE. $$ GR/AC