000 AXNT20 KNHC 211746 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI OCT 21 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 1730 UTC. ...SPECIAL FEATURE... A NEARLY STATIONARY 1008 MB LOW IS OVER THE SW CARIBBEAN NEAR 13N80W. THIS SYSTEM IS INTERACTING WITH A WEAK STATIONARY FRONT TO ITS N...AND MONSOONAL FLOW TO ITS S. THIS COMPLEX SCENARIO IS GENERATING A BROAD AREA OF SCATTERED HEAVY SHOWERS AND THUNDERSTORMS W OF 79W. THE ASSOCIATED SHOWER ACTIVITY HAS BECOME BETTER ORGANIZED...AND THERE IS A LIKELIHOOD THAT A TROPICAL DEPRESSION WILL FORM DURING THE WEEKEND. LITTLE MOTION IS ANTICIPATED IN THE SHORT TERM...BUT A SLOW NORTHWARD DRIFT SHOULD BEGIN ON SUNDAY. THIS SYSTEM HAS A HIGH OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...THE ITCZ/THE MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE E TROPICAL ATLC NEAR 14N17W TO 5N27W. A SMALL SECTION OF THE ITCZ DEVELOP THIS MORNING AND WAS ANALYZED FROM 5N27W TO NEAR 5N37W. SCATTERED MODERATE CONVECTION IS FROM 3N-20N E OF 27W. A BROAD AREA OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS AFFECTING THE COASTAL WATERS OF GUYANA...SURINAME...FRENCH GUIANA S OF 12N BETWEEN 48W-60W. A SURFACE TROUGH IS ANALYZED WITHIN THIS REGION FROM 13N53W TO INLAND OVER FAR NE GUYANA NEAR 8N60W. THIS AREA OF CONVECTION WILL LIKELY SPREAD OVER NRN VENEZUELA AND THE SRN WINDWARD ISLANDS DURING THE NEXT FEW DAYS. ...DISCUSSION... GULF OF MEXICO... A COOL AND DRY AIRMASS CONTINUES TO DOMINATE THE WATERS ACROSS THE GULF THIS AFTERNOON. BROAD SURFACE ANTICYCLONIC FLOW COVERS THE AREA. AS THIS AIRMASS SPREADS OVER THE WARM WATERS OF THE GULF...LOW LEVEL STRATOCUMULUS CLOUDS DEVELOP OVER MOST AREAS... EXCEPT THE CENTRAL AND NRN GULF. IN THE UPPER LEVELS OF THE ATMOSPHERE...STRONG SUBSIDENCE ALOFT COVERS THE ENTIRE GULF SUPPORTING THE FAIR WEATHER ENVIRONMENT ACROSS THE AREA. CONDITIONS ARE EXPECTED TO REMAIN CONSTANT OVER THE NEXT 24 HOURS. SURFACE RIDGE WILL CONTINUE TO BUILD ACROSS THE WRN GULF THROUGH TUESDAY. CARIBBEAN SEA... CLUSTERS OF HEAVY SHOWERS AND THUNDERSTORMS CONTINUE TO AFFECT THE NW AND SW BASINS OF THE CARIBBEAN SEA W OF 79W...ASSOCIATED TO THE STATIONARY FRONT EXTENDING ALONG CENTRAL CUBA TO THE ERN COAST OF HONDURAS...AND THE SPECIAL FEATURE LOW PRESSURE SYSTEM LINGERING OVER THE SW BASIN NEAR 13N80W. SHORT RANGE COMPUTER MODELS SUGGEST THE CONVECTION IN THIS REGION WILL LINGER OVER THE NEXT 24 HOURS. ENE TRADE WIND FLOW IS CONVERGING WITH MONSOONAL FLOW COMING FROM NRN SOUTH AMERICA...GENERATING A SCATTERED SHOWERS WITHIN 100 NM OFF THE COAST OF COLOMBIA AND VENEZUELA. OTHERWISE...FAIR WEATHER CONDITIONS PREVAIL ELSEWHERE ACROSS THE AREA...AS A BROAD UPPER CYCLONE IN THE SW ATLC DRAWS DRY AND SUBSIDENT AIR ALOFT SUPPRESSING DEEP CONVECTION ACROSS THE AREA. ATLANTIC OCEAN... A DEEP LAYER TROUGH IS SLOWLY MOVING OFF THE ERN CONUS SEABOARD SUPPORTING A STATIONARY FRONT ANALYZED ACROSS THE THE WRN ATLC ALONG 31N70W TO ACROSS THE CENTRAL BAHAMAS NEAR LONG ISLAND INTO THE CARIBBEAN ACROSS CENTRAL CUBA ALONG CAMAGUEY. SCATTERED MODERATE TO HEAVY SHOWERS AND THUNDERSTORMS ARE WITHIN 60 NM ON EITHER SIDE OF THE BOUNDARY. AS THE UPPER LEVEL TROUGH PUSHES EASTWARD...THE FRONT AND ASSOCIATED CONVECTION IS EXPECTED TO CONTINUE TO SLOWLY PROGRESS ENE DURING THE NEXT 24 HOURS. AN UPPER LEVEL CYCLONIC CIRCULATION IS CENTERED 22N60W. THIS CIRCULATION IS MOVING W-SW WITH WIDELY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS FROM 19N-25N BETWEEN 53W-64W. AN AREA OF BROAD ELONGATED TROUGHINESS AND LOWER PRESSURES IS IN THE CENTRAL TROPICAL ATLC ANALYZED AS A SURFACE TROUGH EXTENDING SW FROM A 1013 MB LOW NEAR 20N37W TO A SECOND 1008 MB LOW NEAR 16N44W THEN SOUTHWARD TO 11N46W. DESPITE THE LOCATION OF THIS SYSTEM...BROAD AREA OF DIFFLUENCE IN THE MID AND UPPER LEVELS IS DISPLACING THE CONVECTION WELL NE OF THE ANALYZED FEATURE FROM 21N-27N BETWEEN 20W-35W. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ GARCIA