000 AXNT20 KNHC 211752 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SUN APR 21 2013 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 1715 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS THE COAST OF SIERRA LEONE NEAR 8N13W TO 5N16W 3N21W. THE ITCZ BEGINS FROM 2N22W AND CONTINUES ALONG EQ30W 1N40W EQ50W. SCATTERED MODERATE CONVECTION IS FROM 1S-5N BETWEEN 10W-30W. SIMILAR CONVECTION IS FROM 1S-6N BETWEEN 45W-53W. ...DISCUSSION... GULF OF MEXICO... AS OF 1500 UTC...THE PORTION OF THE FORMER STATIONARY FRONT OVER THE SE GULF HAS DETACHED FROM THE REMAINDER FRONT AND DRIFTED WESTWARD TOWARDS THE CENTRAL GULF AS A SURFACE TROUGH. THE SURFACE TROUGH EXTENDS ALONG 27N89W 23N91W 18N91W. RAINSHOWERS/ISOLATED THUNDERSTORMS ASSOCIATED TO THIS SURFACE TROUGH ARE S OF 29N E OF 90W BEING ENHANCED BY MIDDLE-UPPER LEVEL MOISTURE BEING ADVECTED BY W-NW WIND FLOW FROM THE E PACIFIC. A PORTION OF THE REMAINDER STATIONARY FRONT EXTENDS OVER THE FLORIDA KEYS ALONG 25N80W 24N82W GENERATING ISOLATED SHOWERS AND THUNDERSTORMS. THE STATIONARY FRONT IS BEING SUPPORTED BY A SHORT-WAVE TROUGH EXTENDING FROM S GEORGIA TO FREEPORT IN THE BAHAMAS. WINDS RANGING FROM 5-15 KT SPREAD OVER THE GULF S OF 27N...NE-E FLOW UP TO 20 KT ASSOCIATED TO SURFACE RIDGING COVERS THE REMAINDER GULF N OF 27N. OVER THE COURSE OF 24 HOURS...THE SURFACE TROUGH IS EXPECTED TO STALL OVER THE CENTRAL GULF WHICH WILL CONTINUE GENERATING RAINSHOWERS OVER THE CENTRAL AND EASTERN GULF. CARIBBEAN SEA... AN UPPER LEVEL HIGH ANCHORED S OF MEXICO NEAR 15N100W EXTENDS TO THE WESTERN CARIBBEAN AND A PORTION OF THE W ATLC. EXCEPT FOR THE YUCATAN CHANNEL WHERE RAINSHOWERS ARE OCCURRING IN ASSOCIATION TO THE SURFACE TROUGH OVER THE GULF...DRY AIR ALOFT EMBEDDED IN THE RIDGE IS PROVIDING FOR THE MOST PART FAIR WEATHER CONDITIONS ACROSS THE WESTERN...CENTRAL AND SOUTHERN CARIBBEAN. PATCHES OF LOW LEVEL HUMIDITY IS PRODUCING RAINSHOWERS S OF CUBA BETWEEN 76W AND 81W AS WELL AS S OF LA HISPANIOLA BETWEEN 69W AND 72W. OVER THE E CARIBBEAN...AN UPPER LEVEL TROUGH WITH AXIS NEAR 62W IS PROVIDING SOME UPPER LEVEL MOISTURE THAT IS ENHANCING RAINSHOWERS OVER THE LESSER ANTILLES. IN TERMS OF WIND... TRADEWIND FLOW OF 5-15 KT SPREADS ACROSS MUCH OF THE BASIN EXCEPT FOR THE EASTERN CARIBBEAN THAT WINDS CAN BE UP TO 20 KT. LITTLE CHANGE IS EXPECTED OVER THE NEXT 24 HOURS. ATLANTIC OCEAN... IN THE W ATLC...A STATIONARY FRONT EXTENDING ALONG 30N75W 28N78W OVER THE FLORIDA KEYS TO 24N82W IS BEING SUPPORTED BY A SHORT- WAVE TROUGH EXTENDING FROM S GEORGIA TO FREEPORT IN THE BAHAMAS. STRONG ISOLATED SHOWERS AND THUNDERSTORMS ASSOCIATED TO THIS FRONTAL BOUNDARY ARE FROM 24N-30N W OF 70W. SURFACE RIDGING FROM A 1033 MB HIGH NEAR 42N39W SPREAD OVER THE ATLC W OF 50W. OVER THE CENTRAL ATLC...AN UPPER LOW POSITIONED NEAR 28N40W IS SUPPORTING A WEAK 1011 MB BROAD SURFACE LOW CENTERED NEAR 25N38W. A SURFACE TROUGH EXTENDS TOWARDS THE SW FROM THE LOW CENTER TO NEAR 19N41W. SCATTERED SHOWERS ASSOCIATED TO THIS LOW ARE FROM 26N-30N BETWEEN 35W-45W. AN UPPER LEVEL RIDGE ALONG 17W COVERS THE REMAINDER OF THE EAST ATLC SUPPORTING A WEAK 1015 MB HIGH NEAR 23N26W. OVER THE COURSE OF 24 HOURS...THE FRONT OVER THE W ATLC IS EXPECTED TO STALL AND THEN LIFT BACK N OF THE AREA. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NR