000 AXNT20 KNHC 010524 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 105 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 11N14W 5N22W 5N33W 4N42W 1N59W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 3N-8N BETWEEN 19W-23W. SCATTERED MODERATE CONVECTION IS FROM 3N-8N BETWEEN 23W-34W. SCATTERED MODERATE CONVECTION IS ALSO FROM 5N-8N BETWEEN 40W-44W. ...DISCUSSION... GULF OF MEXICO... A VIGOROUS DEEP LAYER TROUGH OVER THE E CONUS EXTENDS INTO NE MEXICO...WITH TWO ASSOCIATED SURFACE COLD FRONTS...ONE COLD FRONT OVER THE E GULF AND THE OTHER COLD FRONT OVER THE NW GULF. THE COLD FRONT OVER THE E GULF EXTENDS FROM NE FLORIDA NEAR 31N82W TO 26N84W TO THE YUCATAN PENINSULA NEAR 21N88W. THE COMBINATION OF INSTABILITY AND STRONG DEEP LAYER WIND SHEAR ALONG AND E OF THE FRONT IS GENERATING A LINE OF SHOWERS AND THUNDERSTORMS EXTENDING FROM 31N77W TO 25N83W. THIS ACTIVITY IS SUPPORTING A 1009 MB SURFACE HIGH W OF THE S FLORIDA PENINSULA NEAR 26N82W. ADDITIONALLY...THIS ACTIVITY IS BEING ENHANCED BY PARTICULARLY STRONG UPPER LEVEL DIVERGENCE IN THE SE QUADRANT OF A 140-150 KT UPPER LEVEL JET MAXIMUM ORIENTED FROM SOUTH-SOUTHWEST TO NORTH-NORTHEAST OVER THE SE CONUS. THE COLD FRONT OVER THE NW GULF EXTENDS FROM S ALABAMA NEAR 30N87W TO 28N92W TO 26N97W...WITH STABLE ATMOSPHERIC CONDITIONS SUPPRESSING DEEP CONVECTION IN THE VICINITY OF THIS FRONT. ADDITIONALLY...BETWEEN THE TWO COLD FRONTS...A 1013 MB SURFACE HIGH IS PRESENT OVER E MEXICO NEAR 24N98W...WHICH IS FURTHER SUPPRESSING DEEP CONVECTION OVER THE W GULF. IN THE WAKE OF THE COLD FRONTS...COOLER AND DRIER CONDITIONS ARE PRESENT. ALSO...GALE CONDITIONS ARE FORECAST TO OCCUR FOR PORTIONS OF THE MIDDLE AND EAST GULF DURING THE NEXT DAY. CARIBBEAN SEA... IN THE SW CARIBBEAN...A 1009 MB SURFACE LOW IS CENTERED E OF NICARAGUA NEAR 12N82W. LOW LEVEL CONVERGENCE NEAR THIS SURFACE LOW IS SUPPORTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS S OF 17N W OF 79W...INCLUDING PORTIONS OF PANAMA...COSTA RICA...AND NICARAGUA. THIS ACTIVITY IS BEING ENHANCED BY UPPER LEVEL DIFFLUENCE IN THE VICINITY OF AN UPPER RIDGE PRESENT OVER THE W CARIBBEAN...WITH THE AXIS OF THIS UPPER RIDGE EXTENDING FROM N COLOMBIA NEAR 12N72W TO 17N75W TO 20N84W TO E CUBA NEAR 21N76W. OVER THE E CARIBBEAN...A SURFACE TROUGH EXTENDS FROM 16N64W TO 13N65W TO N VENEZUELA NEAR 10N65W. DEEP LAYER DRY AIR OVER THE E CARIBBEAN IS SUPPRESSING DEEP CONVECTION NEAR THIS SURFACE TROUGH...WITH GENERALLY FAIR WEATHER PRESENT ACROSS THE E CARIBBEAN. THE SURFACE COLD FRONT OVER THE E GULF OF MEXICO IS EXPECTED TO ENTER THE NW CARIBBEAN OVER THE NEXT DAY. ATLANTIC OCEAN... A VIGOROUS DEEP LAYER TROUGH IS OVER THE E CONUS. STRONG UPPER LEVEL DIVERGENCE...COMBINED WITH INSTABILITY AND STRONG DEEP LAYER WIND SHEAR...IS GENERATING A LINE OF SHOWERS AND THUNDERSTORMS EXTENDING FROM 31N77W TO 25N83W. THIS ACTIVITY IS BEING ENHANCED BY LOW LEVEL CONVERGENCE IN THE VICINITY OF A SURFACE COLD FRONT THAT EXTENDS FROM NE FLORIDA NEAR 31N82W TO 26N84W INTO THE S GULF. OVER THE NEXT DAY...THE COLD FRONT IS FORECAST TO MOVE SOUTHEASTWARD ACROSS PORTIONS OF THE W ATLC. IN THE WAKE OF THE COLD FRONT...RELATIVELY COOLER AND DRIER CONDITIONS ARE PRESENT. ADDITIONALLY...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 28N56W...WITH SUBSIDENCE AND FAIR WEATHER IN THE VICINITY OF THE SURFACE HIGH. FARTHER TO THE E...A SURFACE TROUGH EXTENDS FROM 27N37W TO 32N37W TO A 1012 MB SURFACE LOW NEAR 34N37W...WITH LOW LEVEL CONVERGENCE NEAR THESE FEATURES RESULTING IN SCATTERED SHOWERS N OF 29N BETWEEN 34W-41W. THIS ACTIVITY IS BEING ENHANCED BY ATMOSPHERIC INSTABILITY IN THE VICINITY OF AN UPPER TROUGH WITH AN AXIS EXTENDING FROM 26N41W TO 31N38W TO AN UPPER LOW NEAR 34N38W. ALSO...A SURFACE TROUGH EXTENDS FROM 31N34W TO 25N35W TO 20N40W TO 9N55W...WITH LOW LEVEL CONFLUENCE RESULTING IN SCATTERED SHOWERS WITHIN 60 NM EITHER SIDE OF THIS FEATURE. THIS ACTIVITY N OF 16N IS BEING ENHANCED BY UPPER LEVEL DIVERGENCE IN THE VICINITY OF A 100-110 KT UPPER LEVEL JET MAXIMUM OVER THE E PACIFIC. ACROSS THE E ATLC...A SURFACE WARM FRONT EXTENDS FROM 28N27W TO 32N29W...WITH SCATTERED SHOWERS WITHIN 90 NM EITHER SIDE OF THIS FRONT. ALSO...A SURFACE COLD FRONT EXTENDING FROM 29N14W TO 29N11W EASTWARD ACROSS N AFRICA IS ASSOCIATED WITH AN UPPER TROUGH OVER PORTIONS OF N AFRICA...AND A SURFACE TROUGH EXTENDS FROM A 1011 MB SURFACE LOW OVER SENEGAL NEAR 13N14W TO 19N17W TO 25N16W...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 16N BETWEEN THE AFRICAN COAST AND 39W...WITH AN UPPER HIGH NEAR 7N17W. UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THIS UPPER RIDGE AND UPPER HIGH IS ENHANCING CONVECTION IN THE VICINITY OF THE ITCZ BETWEEN E OF 34W. 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/GR