000 AXNT20 KNHC 191134 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 705 AM EST WED NOV 19 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 1115 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 43W S OF 17N MOVING W 10-15 KT. THIS TROPICAL WAVE COINCIDES WITH A DEEP LAYER MOISTURE MAXIMUM BASED ON TOTAL PRECIPITABLE WATER PRODUCT FROM CIMSS. ALSO...CIMSS WAVETRAK PRODUCT INDICATES A MAXIMUM IN LOW LEVEL CYCLONIC CIRCULATION ALONG THE WAVE AXIS. SCATTERED MODERATE CONVECTION IS FROM 7N-15N BETWEEN 41W-49W. A TROPICAL WAVE IS ALONG 73W/74W S OF 16N MOVING W 10-15 KT. A MAXIMUM IN DEEP LAYER MOISTURE COINCIDES WITH THIS WAVE. ALSO...UPPER AIR TIME-HEIGHT ANALYSIS FOR CURACAO...LOCATED IN THE NETHERLANDS ANTILLES NEAR 12N69W...DEPICTS VEERING OF MEAN LOW/MID-LEVEL FLOW FROM NE TO SE OVER THE LAST DAY SUGGESTING WAVE PASSAGE. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM EITHER SIDE OF THIS WAVE S OF 12N...INCLUDING PORTIONS OF N COLOMBIA AND NW VENEZUELA. ...THE ITCZ... THE ITCZ AXIS IS ANALYZED ALONG 9N12W 6N22W 6N36W 10N51W 8N60W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 150 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 26W-34W. SCATTERED MODERATE CONVECTION IS FROM 9N-14N BETWEEN 53W-60W. ...DISCUSSION... GULF OF MEXICO... STRONG WEST-NORTHWESTERLY FLOW ALOFT AND DEEP LAYER DRY AIR ARE PRESENT OVER MUCH OF THE GULF REGION. ALSO...A MODIFIED CONTINENTAL POLAR AIRMASS PERSISTS ACROSS THE GULF REGION. AS A RESULT... TEMPERATURES ACROSS THE GULF REGION ARE BELOW SEASONAL AVERAGES. THIS RELATIVELY COOLER AND DRIER AIRMASS IS BEING REINFORCED BY A SURFACE COLD FRONT THAT EXTENDS FROM THE SE TEXAS COAST NEAR 29N95W TO 24N85W TO S OF FLORIDA NEAR 24N82W. WITH INCREASED N TO NE WINDS SUPPORTING LOW-LEVEL COLD AIR ADVECTION IN THE WAKE OF THE COLD FRONT...FREEZE WARNINGS AND WIND CHILL ADVISORIES ARE IN EFFECT FOR THIS MORNING...WITH FREEZE WATCHES IN EFFECT FOR LATE TONIGHT THROUGH THURSDAY MORNING...FOR PORTIONS OF FLORIDA. ALSO...A 1029 MB SURFACE HIGH IS CENTERED OVER NE MEXICO NEAR 25N99W...WITH AN ASSOCIATED SURFACE RIDGE EXTENDING INTO THE W GULF. AS THE COOLER AIR IS BEING ADVECTED OVER THE RELATIVELY WARMER GULF WATERS...WEAK LOW LEVEL INSTABILITY IS SUPPORTING SCATTERED STRATOCUMULUS CLOUDS ACROSS THE GULF. HOWEVER...SUBSIDENCE AND STABLE ATMOSPHERIC CONDITIONS HIGHER IN THE ATMOSPHERE ARE INHIBITING DEEP CONVECTION ACROSS THE GULF REGION. ADDITIONALLY...STRONG NORTHERLY SURFACE WINDS ARE BLOWING THROUGH THE ISTHMUS OF TEHUANTEPEC RESULTING IN STORM FORCE WINDS IN THE E PACIFIC REGION. CARIBBEAN SEA... ACROSS THE NW CARIBBEAN...A SURFACE STATIONARY FRONT EXTENDS FROM W OF HAITI NEAR 20N74W TO 16N80W TO N COSTA RICA NEAR 11N85W. LOW LEVEL CONVERGENCE NEAR THIS FRONT IS INTERACTING WITH DEEP MOISTURE OVER THE W CARIBBEAN TO GENERATE SCATTERED SHOWERS AND THUNDERSTORMS S OF 17N W OF 73W. THIS ACTIVITY IS BEING ENHANCED BY UPPER LEVEL DIVERGENCE IN THE VICINITY OF AN UPPER RIDGE PRESENT OVER THE W CARIBBEAN...WITH THE AXIS OF THIS UPPER RIDGE EXTENDING FROM N COLOMBIA NEAR 11N73W TO 15N79W TO 18N83W. THIS ACTIVITY IS ALSO BEING ENHANCED BY THE TROPICAL WAVE ALONG 73W/74W. OVER THE E CARIBBEAN...AN UPPER LEVEL RIDGE EXTENDS FROM N VENEZUELA NEAR 10N66W TO 16N64W TO 18N63W TO THE SW ATLC...WITH UPPER LEVEL DIVERGENCE SUPPORTING SCATTERED SHOWERS OVER THE E CARIBBEAN S OF 15N E OF 70W. ATLANTIC OCEAN... A VIGOROUS UPPER TROUGH IS OVER THE E CONUS AND THE W ATLC... WHICH IS SUPPORTING A SURFACE STATIONARY FRONT AND TWO SURFACE COLD FRONTS. THE STATIONARY FRONT EXTENDS FROM W OF HAITI NEAR 20N74W TO 27N64W TO 31N61W AND EXTENDS FARTHER TO THE NE AS A DISSIPATING SURFACE STATIONARY FRONT. ISOLATED SHOWERS ARE WITHIN 60 NM EITHER SIDE OF THE STATIONARY FRONT. TO THE W OF THIS STATIONARY FRONT...A MODIFIED CONTINENTAL POLAR AIRMASS IS IN PLACE...WITH TEMPERATURES BELOW SEASONAL AVERAGES ACROSS FLORIDA. THIS RELATIVELY COOLER AND DRIER AIRMASS IS BEING REINFORCED BY A SURFACE COLD FRONT THAT EXTENDS FROM S OF FLORIDA NEAR 24N82W TO 27N70W TO 32N65W TO NE OF THE DISCUSSION AREA...WITH SCATTERED STRATOCUMULUS CLOUDS BETWEEN THIS FRONT AND THE COAST OF THE SE CONUS. ANOTHER SURFACE COLD FRONT EXTENDS FROM 31N69W TO 32N68W TO NE OF THE DISCUSSION AREA. FARTHER TO THE E...A 1016 MB SURFACE HIGH IS CENTERED NEAR 27N54W...WHICH IS BEING SUPPORTED BY AN UPPER LEVEL RIDGE WITH AN AXIS EXTENDING FROM 18N63W TO 23N58W TO 32N51W TO N OF THE DISCUSSION AREA. FARTHER TO THE E...AN UPPER LOW IS CENTERED NEAR 32N39W THAT IS ACCOMPANIED BY AN UPPER TROUGH N OF 22N BETWEEN 24W-40W. THIS UPPER LOW AND UPPER TROUGH ARE ACCOMPANIED A 1010 MB SURFACE LOW NEAR 30N42W...ANOTHER 1010 MB SURFACE LOW CENTERED NEAR 29N47W...AND A SURFACE TROUGH EXTENDING FROM 22N35W TO 26N33W TO 31N34W. LOW LEVEL CONVERGENCE NEAR THESE TWO SURFACE LOWS AND THE SURFACE TROUGH IS SUPPORTING SCATTERED SHOWERS N OF 21N BETWEEN 24W-32W...WITH ISOLATED SHOWERS N OF 28N BETWEEN 33W-48W. OVER THE TROPICAL ATLC...AN UPPER RIDGE IS S OF 6N BETWEEN 21W-39W. UPPER LEVEL DIVERGENCE IN THE VICINITY OF THIS UPPER RIDGE IS ENHANCING THE CONVECTION ASSOCIATED WITH THE ITCZ...AS WELL AS THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVE ALONG 43W. $$ COHEN