000 AXNT20 KNHC 191749 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT WED OCT 19 2011 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...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1745 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED FROM NEAR 19N30W TO 8N41W MOVING W AT 8-12 KT. WAVE IS WELL DEFINED IN THE LOW LEVEL CLOUD FIELD AND IS EMBEDDED WITHIN A DEEP SURGE OF MOISTURE DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION ARE FROM 7N-20N BETWEEN 25W-42W. TROPICAL WAVE IS ANALYZED IN THE CENTRAL TROPICAL ATLC FROM 13N49W TO 6N52W MOVING W 10-15 KT. WAVE IS WELL DEFINED AND IS EMBEDDED WITHIN A MOISTURE SURGE DEPICTED ON TOTAL PRECIPITABLE WATER IMAGERY. CLUSTERS OF SCATTERED MODERATE TO STRONG CONVECTION ARE FROM 5N-13N BETWEEN 42W-54W. THE TROPICAL WAVE THAT WAS MOVING ACROSS THE CARIBBEAN OVER THE PAST FEW DAYS HAS LOST ITS WAVE QUALITIES AND STRUCTURE. THEREFORE...A REMNANT TROUGH AXIS WAS LAST ANALYZED FROM 16N73W TO 10N74W WITH NO CONVECTION IN THE VICINITY OF ITS AXIS. ...THE ITCZ/THE MONSOON TROUGH... THE OCEANIC MONSOON TROUGH HAS BEEN DISRUPTED DUE TO THE LARGE CYCLONIC WIND FIELD ASSOCIATED WITH THE TROPICAL WAVES. THE OTHER PORTION OF IT REMAINS INLAND OVER NRN AFRICA. CONSEQUENTLY ...THE ITCZ IS DISRUPTED BY THE PRESENCE OF THESE TROPICAL WAVES. FOR INFORMATION REGARDING CONVECTION IN THIS REGION SEE TROPICAL WAVES DISCUSSION ABOVE. ...DISCUSSION... THE GULF OF MEXICO... THE AFOREMENTIONED COLD FRONT FROM PREVIOUS DISCUSSIONS IS NOW MOVING ACROSS THE FLORIDA PENINSULA AND THE FAR SE GULF INTO THE ATLANTIC BASIN...ANALYZED ENTERING THE DISCUSSION AREA FROM JUST S OF TAMPA BAY TO THE FAR NE CORNER OF THE YUCATAN PENINSULA. THE SURFACE PRESSURE GRADIENT BEHIND THE FRONT IS FAIRLY TIGHT ...GENERATING NNE FLOW 15-25 KT GUSTING TO NEAR GALE FORCE CRITERIA. SCATTERED HEAVY SHOWERS AND THUNDERSTORMS...SOME SEVERE...ARE AHEAD OF THE FRONT UP TO 110 NM. MOST OF IT IS MOVING ACROSS THE FLORIDA STRAITS. HOWEVER...DOPPLER RADAR IMAGERY INDICATED THE MOST CONVECTIVE AREA IS CURRENTLY MOVING ACROSS THE FLORIDA KEYS AND THE IMMEDIATE COAST OF THE SOUTHERN TIP OF THE PENINSULA. THE FRONT AND ASSOCIATED CONVECTION IS EXPECTED TO MOVE OUT OF THE AREA DURING THE AFTERNOON HOURS WITH SOME SHOWERS LINGERING THROUGH THE NEXT 24 HOURS. HIGH PRESSURE WILL BUILD OVER THE ENTIRE AREA GULF IN THE WAKE OF THE FRONT THROUGH SATURDAY. THE CARIBBEAN SEA... STRONG SHOWERS AND THUNDERSTORMS CONTINUE TO AFFECT THE FAR NW BASIN AND YUCATAN CHANNEL W OF 83W...ASSOCIATED TO THE COLD FRONT MENTIONED IN THE ATLC AND GULF OF MEX DISCUSSIONS. SIMILAR ACTIVITY COVERS THE SW BASIN RELATED TO MONSOONAL FLOW ACROSS THIS AREA...GENERATING SCATTERED MODERATE TO HEAVY SHOWERS S OF 15N W OF 75W. OTHERWISE...FAIR WEATHER CONDITIONS PREVAIL ELSEWHERE ACROSS THE AREA...AS A BROAD UPPER ANTICYCLONE DRAWS DRY/SUBSIDENT AIR ALOFT SUPPRESSING DEEP CONVECTION ACROSS THE AREA. THE FRONT IS EXPECTED TO FULLY ENTER THE NW CARIBBEAN THIS AFTERNOON...GENERATING SIMILAR CONVECTION TO THE COASTAL WATERS FROM HONDURAS TO COLOMBIA OFF TO 180 NM OFFSHORE W OF 75W. AS THE COOLER/DRYER AIRMASS MIXES WITH THE TROPICAL AIRMASS...THE FRONT WILL BECOME NEARLY STATIONARY DURING THE NEXT 48 HOURS. THE ATLANTIC OCEAN... A DEEP LAYER TROUGH/CUT OFF LOW SWINGS ACROSS THE ERN CONUS SUPPORTING A VIGOROUS COLD FRONT SOON TO BE MOVING OFF THE ERN SEABOARD. PRE FRONTAL CONVECTION IS ALREADY IMPACTING THE FAR WRN ATLC SINCE THE EARLY HOURS OF THE DAY...AND CAN BE TRACKED ALONG THE PRE FRONTAL TROUGH ANALYZED ALONG 30N80W TO ACROSS THE SOUTHERN FLORIDA PENINSULA AND STRAITS INTO WRN CUBA. SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS ARE MOSTLY W OF 75W. THE SURFACE PRESSURE GRADIENT AHEAD OF THE FRONT CONTINUES TO BECOME COMPACTED LEADING TO GALE FORCE WINDS AND SEAS 9 TO 14 FT EXPECTED TO DEVELOP DURING THE AFTERNOON HOURS. THE FRONT AND ASSOCIATED CONVECTION IS EXPECTED TO CONTINUE TO PROGRESS EASTWARD DURING THE NEXT 48 HOURS. A BROAD UPPER ANTICYCLONE COVERS THE REST OF THE WRN ATLC AHEAD OF THE FRONTAL CONVECTION ...AND A BROAD SURFACE RIDGE OF HIGH PRESSURE ANCHORED N OF THE DISCUSSION AREA ARE KEEPING FAIR CONDITIONS ELSEWHERE ACROSS THE CENTRAL AND ERN BASINS N OF 20N. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA