000 AXNT20 KNHC 011129 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST MON DEC 01 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 9N13W 5N22W 5N31W 5N40W 1N51W. SCATTERED MODERATE CONVECTION IS FROM 5N-9N BETWEEN 12W-17W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 3N-8N BETWEEN 20W-29W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 33W-37W. SCATTERED MODERATE CONVECTION IS ALSO FROM 5N-8N BETWEEN 42W-47W. ...DISCUSSION... GULF OF MEXICO... A VIGOROUS DEEP LAYER TROUGH OVER THE E CONUS...WITH AN ASSOCIATED 140-150 KT OVER THE SE CONUS...EXTENDS ACROSS THE GULF REGION...WITH AN ASSOCIATED SURFACE COLD FRONT EXTENDING FROM THE FLORIDA BIG BEND NEAR 30N83W ACROSS THE GULF TO 24N91W TO 25N96W...AND A SURFACE STATIONARY FRONT THAT EXTENDS FROM 25N96W TO 26N98W AND EXTENDS WESTWARD ACROSS NORTHERN MEXICO. AS COOLER AIR IS ADVECTED OVER THE RELATIVELY WARMER GULF WATERS...LOW LEVEL INSTABILITY IS SUPPORTING SCATTERED STRATOCUMULUS CLOUDS OVER THE GULF IN THE WAKE OF THE FRONT N OF 25N. THE PRESENCE OF DEEP LAYER DRY AIR AND STABLE ATMOSPHERIC CONDITIONS HIGHER IN THE ATMOSPHERE ARE PREVENTING THE DEVELOPMENT OF DEEP CONVECTION ACROSS THE GULF REGION. SUBSIDENCE IS OCCURRING OVER THE NW GULF IN THE VICINITY OF A SURFACE RIDGE EXTENDING SOUTHEASTWARD FROM A 1021 MB SURFACE HIGH NEAR THE TEXAS-MEXICO BORDER NEAR 29N101W. GALE CONDITIONS ARE FORECAST TO OCCUR FOR PORTIONS OF THE MIDDLE AND EAST GULF DURING THE NEXT DAY. STRONG N TO NE SURFACE WINDS ARE FORECAST TO BLOW THROUGH THE ISTHMUS OF TEHUANTEPEC RESULTING IN GALE FORCE WINDS IN THE EAST PACIFIC REGION BEGINNING AT 02/0600 UTC. CARIBBEAN SEA... A SECOND COLD FRONT THAT IS ALSO ASSOCIATED WITH THE VIGOROUS E CONUS AND GULF REGION DEEP LAYER TROUGH IS ENTERING THE NW CARIBBEAN...AND EXTENDS FROM W CUBA NEAR 23N83W TO THE NW CARIBBEAN NEAR 21N85W TO THE YUCATAN PENINSULA NEAR 19N90W. LOW LEVEL CONVERGENCE WITH THIS FRONT...INSTABILITY ALONG AND AHEAD OF THE FRONT...AND STRONG DEEP LAYER WIND SHEAR OVER THE NW CARIBBEAN ARE SUPPORTING SCATTERED SHOWERS AND THUNDERSTORMS N OF 18N BETWEEN 76W-83W...INCLUDING PORTIONS OF CENTRAL CUBA. THIS ACTIVITY IS BEING ENHANCED BY UPPER LEVEL DIVERGENCE IN THE SE QUADRANT OF THE VIGOROUS 140-150 KT UPPER LEVEL JET MAXIMUM FROM THE SE CONUS. IN THE SW CARIBBEAN...A 1009 MB SURFACE LOW IS CENTERED E OF NICARAGUA NEAR 13N83W. LOW LEVEL CONVERGENCE NEAR THIS SURFACE LOW IS SUPPORTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS S OF 16N W OF 79W. THIS ACTIVITY IS BEING ENHANCED BY UPPER LEVEL DIVERGENCE IN MOIST SOUTHWESTERLY FLOW ALOFT. OVER THE CENTRAL AND E CARIBBEAN...AN UPPER RIDGE IS PRESENT...WHERE SUBSIDENCE AND DEEP LAYER DRY AIR ARE RESULTING IN GENERALLY FAIR WEATHER. HOWEVER...SUFFICIENT LOW LEVEL CONVERGENCE IS GENERATING SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF A SURFACE TROUGH OVER THE E CARIBBEAN THAT EXTENDS FROM 16N64W TO 13N65W TO N VENEZUELA NEAR 10N66W. ATLANTIC OCEAN... A VIGOROUS DEEP LAYER TROUGH IS OVER THE E CONUS AND GULF. STRONG UPPER LEVEL DIVERGENCE ASSOCIATED WITH AN UPPER LEVEL JET MAXIMUM OVER THE SE CONUS...COMBINED WITH INSTABILITY AND STRONG DEEP LAYER WIND SHEAR...IS GENERATING SCATTERED SHOWERS AND THUNDERSTORMS N OF 21N BETWEEN 71W-78W...INCLUDING PORTIONS OF CENTRAL CUBA AND THE BAHAMAS. THIS ACTIVITY IS BEING ENHANCED BY LOW LEVEL CONVERGENCE IN THE VICINITY OF A SURFACE COLD FRONT THAT EXTENDS FROM W CUBA NEAR 23N83W TO 28N77W TO 32N76W AND BEYOND THE DISCUSSION AREA. IN THE WAKE OF THE COLD FRONT... RELATIVELY COOLER AND DRIER CONDITIONS ARE PRESENT. GALE CONDITIONS ARE FORECAST DURING THE NEXT DAY OVER PORTIONS OF THE W ATLC. TO THE E...A 1025 MB SURFACE HIGH IS PRESENT NEAR 29N56W...WITH SUBSIDENCE AND FAIR WEATHER IN THE VICINITY OF THE SURFACE HIGH. FARTHER TO THE E...A SURFACE TROUGH EXTENDS FROM 27N37W TO 30N36W TO A 1012 MB SURFACE LOW NEAR 34N37W...WITH LOW LEVEL CONVERGENCE NEAR THESE FEATURES RESULTING IN SCATTERED SHOWERS N OF 28N BETWEEN 36W-39W. THIS ACTIVITY IS BEING ENHANCED BY ATMOSPHERIC INSTABILITY IN THE VICINITY OF AN UPPER TROUGH WITH AN AXIS EXTENDING FROM 15N56W TO 24N41W TO AN UPPER LOW NEAR 36N37W. ALSO...A SURFACE TROUGH EXTENDS FROM 9N55W TO 18N39W TO 30N32W...WITH LOW LEVEL CONFLUENCE RESULTING IN SCATTERED SHOWERS WITHIN 90 NM EITHER SIDE OF THIS FEATURE. THE ACTIVITY N OF 15N IS BEING ENHANCED BY UPPER LEVEL DIVERGENCE IN THE VICINITY OF A 90-100 KT UPPER LEVEL JET MAXIMUM OVER THE E ATLC. ALSO ACROSS THE E ATLC...A WEAKENING SURFACE WARM FRONT EXTENDS FROM 25N25W TO 32N28W TO NW OF THE DISCUSSION AREA...WITH SCATTERED SHOWERS WITHIN 120 NM EITHER SIDE OF THIS FRONT. ALSO...A WEAKENING SURFACE COLD FRONT E OF THE CANARY ISLANDS EXTENDS FROM 27N14W TO 27N13W EASTWARD ACROSS N AFRICA...WHICH IS ASSOCIATED WITH AN UPPER TROUGH OVER PORTIONS OF N AFRICA...AND A SURFACE TROUGH EXTENDS FROM A 1010 MB SURFACE LOW OVER SENEGAL NEAR 13N14W TO 15N15W TO 17N15W...WITH DEEP LAYER DRY AIR INHIBITING DEEP CONVECTION IN THE VICINITY OF THE SURFACE COLD FRONT...LOW...AND TROUGH. ADDITIONALLY...AN UPPER RIDGE IS S OF 18N BETWEEN THE AFRICAN COAST AND 37W...WITH AN UPPER HIGH NEAR 8N14W. UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THIS UPPER RIDGE AND UPPER HIGH IS ENHANCING CONVECTION IN THE VICINITY OF THE ITCZ E OF 37W. 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. $$ COHEN/MT/GR