000 AXNT20 KNHC 180554 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE OCT 18 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... A BROAD AREA OF LOW PRESSURE THAT COVERS THE FAR NW CARIBBEAN... SE GULF OF MEXICO AND THE YUCATAN PENINSULA CONTINUES TO PRODUCE A LARGE AREA OF SHOWERS/THUNDERSTORMS WELL REMOVED FROM THE LOW LEVEL CENTER. THE POTENTIAL FOR THIS SYSTEM TO DEVELOP APPEARS TO BE DECREASING AND NOW HAS A LOW CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT BEGINS TO MOVE N-NE AT 9-13 KT. REGARDLESS OF DEVELOPMENT...THIS SYSTEM IS EXPECTED TO CONTINUE TO PRODUCE LOCALLY HEAVY RAINFALL...GUSTY WINDS...AND POSSIBLE SEVERE WEATHER OVER THE FLORIDA KEYS...THE FLORIDA PENINSULA...SOUTHERN GEORGIA...AND COASTAL SECTIONS OF THE CAROLINAS OVER THE NEXT DAY OR SO. ...TROPICAL WAVES... TROPICAL WAVE IS ANALYZED FROM 14N27W TO 7N33W MOVING W AT NEAR 15 KT. WAVE IS EMBEDDED WITHIN BROAD AREA OF MOISTURE AS DEPICTED ON THE TOTAL PRECIPITABLE WATER IMAGERY. WAVE IS BENEATH AN UPPER RIDGE ENHANCING SCATTERED MODERATE/STRONG CONVECTION FROM 13N-16N BETWEEN 22W-30W INCLUDING THE SOUTHERN MOST CAPE VERDE ISLANDS. TROPICAL WAVE IS ANALYZED IN THE CENTRAL TROPICAL ATLC FROM 13N45W TO 6N49W MOVING W NEAR 15 KT. SCATTERED MODERATE/STRONG CONVECTION IS FROM 6N-8N BETWEEN 46W-51W. TROPICAL WAVE IS ANALYZED IN THE E CARIBBEAN FROM 20N65W TO 10N67W MOVING 10-15 KT. WAVE IS WELL DEFINED IN THE UPPER LEVEL SATELLITE WINDS S OF 16N AND IN THE LOW LEVEL CLOUD PATTERN ON SATELLITE IMAGERY ALSO S OF 16N. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE S OF 14N TO THE COAST OF VENEZUELA BETWEEN 63W-70W. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA TO THE COAST NEAR 18N16W. THE ITCZ IS DISRUPTED BY THE PRESENCE OF THE TROPICAL WAVES. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 150 NM ALONG THE COAST OF W AFRICA FROM LIBERIA/ SIERRA LEONE BORDER TO SENEGAL/MAURITANIA BORDER. A PAIR OF 1008 MB LOW ARE ANALYZED BETWEEN THE TROPICAL WAVES NEAR 9N37W AND 9N43W. ...DISCUSSION... GULF OF MEXICO... A 1003 MB LOW IS CENTERED ALONG THE N COAST OF THE YUCATAN PENINSULA NEAR 22N89W. SCATTERED/NUMEROUS STRONG CONVECTION IS FROM THE COAST OF CUBA TO 25N BETWEEN 83W-86W WITH SCATTERED TO HEAVY RAINS COVERING THE REMAINDER OF THE AREA S OF 27N E OF 87W TO OVER FLORIDA AND THROUGH THE STRAITS OF FLORIDA. A BROAD UPPER RIDGE COVERS THE GULF ANCHORED IN THE YUCATAN CHANNEL. THERE IS A DISTINCT BOUNDARY BETWEEN THE MOIST TROPICAL AIR TO THE SE AND STRONG SUBSIDENCE/DRY STABLE AIR TO THE NW THAT EXTENDS FROM CEDAR KEY FLORIDA ALONG 24N90W TO TUXPAN MEXICO. THE LOW CENTER IS EXPECTED TO TRACK SLOWLY NE TONIGHT AND LIKELY WEAKEN REACHING NEAR 24N88W TUE MORNING THEN MOVE INLAND ACROSS THE FLORIDA BIG BEND REGION TUE NIGHT. A TROUGH WILL TRAIL SW FROM THE LOW IN ADVANCE OF A STRONG COLD FRONT THAT WILL ENTER THE NW WATERS EARLY TUE THEN WILL MOVE QUICKLY SE ACROSS THE GULF WED EVENING. HIGH PRESSURE WILL BUILD OVER THE GULF IN THE WAKE OF THE FRONT THROUGH SAT. CARIBBEAN SEA... THE UPPER RIDGE ANCHORED OVER THE YUCATAN CHANNEL COVERS MOST OF THE CARIBBEAN NW OF A LINE FROM GUADELOUPE IN THE LEEWARD ISLANDS TO THE GUAJIRA PENINSULA OF COLOMBIA. A BROAD E/W UPPER RIDGE COVERS THE SE CARIBBEAN EXTENDING ACROSS THE TROPICAL ATLC. EASTERLY SURFACE FLOW COMBINED WITH THE EASTERLY FLOW ALOFT OVER THE SW CARIBBEAN IS GENERATING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS S OF 12N BETWEEN 73W-79W TO INLAND OVER COLOMBIA WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS S OF 14N W OF 79W TO INLAND OVER CENTRAL AMERICA. THE TROPICAL WAVE WILL DAMPEN OUT OVER THE CENTRAL CARIBBEAN BY MID WEEK. A COLD FRONT WILL PUSH INTO THE NW CARIBBEAN WED EVENING REACHING FROM CENTRAL CUBA TO E HONDURAS BY LATE THU WHERE IT WILL STALL. ATLANTIC OCEAN... AN UPPER RIDGE AXIS EXTENDS FROM THE YUCATAN CHANNEL ACROSS S FLORIDA NEAR 25N80W ALONG 26N67W TO 30N50W PROVIDING A DIFFLUENT ENVIRONMENT TO ENHANCE SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 150 NM OF LINE FROM FLORIDA NEAR 27N80W ALONG 29N70W TO 32N52W. AN UPPER TROUGH EXTENDS ACROSS THE CENTRAL ATLC FROM AN UPPER LOW 30N30W THROUGH A SECOND WEAKER UPPER LOW NEAR 20N52W NARROWING INTO THE W TROPICAL ATLC TO NEAR 16N57W. THE NORTHERN UPPER LOW IS SUPPORTING A WEAK 1016 MB LOW CENTERED NEAR 32N35W WITH A SURFACE TROUGH EXTENDING S ALONG 30N33W TO 27N34W WITH SCATTERED SHOWERS/THUNDERSTORMS FROM 30N-33N BETWEEN 26W-33W. A WEAK SURFACE RIDGE COVERS MOST OF THE ATLC N OF 20N E OF 75W WITH A WEAKNESS IN THE VICINITY OF THE ABOVE LOW/TROUGH. A BROAD UPPER RIDGE EXTENDS E/W ACROSS THE TROPICAL ATLC. THE SURFACE RIDGE OVER THE W ATLC WILL SHIFT E ALONG 30N THROUGH TUE. THE LOW IN THE GULF OF MEXICO WILL SHIFT N-NE TUE AND WED AHEAD OF A STRONG COLD FRONT THAT WILL MOVE OFF THE NE FLORIDA COAST WED EVENING THEN WILL REACH FROM 31N74W TO CENTRAL CUBA BY EARLY THU WHERE IT WILL WEAKEN AND BECOME STATIONARY FROM NEAR 31N70W TO CENTRAL CUBA FRI. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW