000 AXNT20 KNHC 162338 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT MAY 16 2015 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...ITCZ/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS ACROSS AFRICA INTO THE TROPICAL ATLC NEAR 10N14W TO 5N20W WHERE THE ITCZ BEGINS AND CONTINUES ALONG 4N28W 2N34W 2N41W TO 3N49W. CLUSTERS OF SCATTERED MODERATE/ ISOLATED STRONG CONVECTION ARE FROM 4N TO S OF THE EQUATOR E OF 5W ACROSS THE PRIME MERIDIAN...FROM 6N-8N E OF 17W TO INLAND OVER N LIBERIA AND SIERRA LEONE...AND FROM 1N-5N BETWEEN 16W- 25W. A SURFACE TROUGH EXTENDS FROM 8N51W TO JUST OFF THE COAST OF SOUTH AMERICA NEAR 3N51W WITH CLUSTERS OF SCATTERED MODERATE CONVECTION WITHIN 60 NM E AND 120 NM W OF THE TROUGH AXIS. ...DISCUSSION... GULF OF MEXICO... AN UPPER RIDGE ANCHORED IN THE E PACIFIC REGION EXTENDS A RIDGE AXIS ACROSS S MEXICO NEAR VERACRUZ TO 24N91W WITH A SECOND BROAD UPPER RIDGE EXTENDING FROM TAMPA BAY FLORIDA TO OVER THE E CONUS TO THE GREAT LAKES. A CUTOFF UPPER LOW IS IN THE NW CARIBBEAN COVERING THE SE GULF OF MEXICO AND GENERATING SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS INLAND AND WITHIN 45 NM ALONG THE N COAST OF CUBA AND WITHIN 90 NM OF THE W TIP CUBA IN THE YUCATAN CHANNEL. AT THE SURFACE IS A SURFACE RIDGE THAT EXTENDS FROM THE W ATLC OVER THE SE CONUS ALONG THE N GULF COAST COVERING THE GULF. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS HAVE DEVELOPED INLAND ALONG THE W COAST OF FLORIDA BETWEEN NAPLES AND TAMPA BAY AND ARE DRIFTING INTO THE GULF WATERS. THE SURFACE RIDGE IS GIVING THE GULF SOUTHERLY RETURN FLOW AND IS GENERATING ISOLATED SHOWERS N OF 26N BETWEEN 92W-96W TO INLAND OVER LOUISIANA AND E TEXAS. THIS SOUTHERLY FLOW WILL CONTINUE THROUGH MON. A SURFACE HIGH WILL DEVELOP OVER THE NE GULF MON NIGHT AND THEN MEANDER OVER NE GULF THROUGH THU. CARIBBEAN SEA... A CUTOFF UPPER LOW IS IN THE NW CARIBBEAN OFF CUBA NEAR 21N83W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS INLAND AND WITHIN 45 NM ALONG THE S COAST OF CUBA AND INTO THE YUCATAN CHANNEL E OF 86W. AN UPPER RIDGE COVERS THE E CARIBBEAN WITH THE AXIS ALONG 68W. THIS UPPER RIDGE IS ADVECTING TROPICAL MOISTURE ACROSS PANAMA AND COSTA RICA GENERATING SCATTERED TO NUMEROUS SHOWERS/ISOLATED THUNDERSTORMS ACROSS THE SW CARIBBEAN S OF 12N BETWEEN COLOMBIA AND NICARAGUA. THE EASTERLY TRADE WINDS ARE GENERATING AFTERNOON/EVENING ISOLATED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ACROSS THE REMAINDER OF CUBA...PUERTO RICO...HISPANIOLA...AND JAMAICA. FRESH TO STRONG TRADE WINDS ARE EXPECTED IN THE S/CENTRAL CARIBBEAN THROUGH SUN NIGHT. MODERATE TO FRESH TRADE WINDS WILL PREVAIL ACROSS THE REMAINDER OF THE AREA S OF 17N WITH MODERATE TRADE WINDS EXPECTED N OF 17N. ...HISPANIOLA... AFTERNOON/EVENING ISOLATED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS ARE ACROSS THE ISLAND THIS EVENING. THE SW FLOW ALOFT WILL BECOME MORE WESTERLY SUN AS THE UPPER LOW OVER THE NW CARIBBEAN DISSIPATES. EXPECT DAYTIME HEATING AND OROGRAPHIC LIFTING TO GENERATE AFTERNOON SHOWERS AND POSSIBLE THUNDERSTORMS OVER THE NEXT DEW DAYS. ATLANTIC OCEAN... A SURFACE RIDGE COVERS THE W ATLC W OF 60W ANCHORED BY A 1028 MB HIGH ABOUT 230 NM E OF WILMINGTON NORTH CAROLINA AND EXTENDS A RIDGE AXIS OVER THE SE CONUS COVERING THE GULF OF MEXICO. A BROAD UPPER TROUGH COVERS THE W INTO THE CENTRAL ATLC SUPPORTING A COLD FRONT THAT ENTERS THE REGION NEAR 32N48W AND EXTENDS ALONG 27N53W TO 24N57W WHERE IT DISSIPATES ALONG 23N64W TO 23N68W WHERE IT BECOMES A SURFACE TROUGH TO 26N71W. SCATTERED SHOWERS ARE WITHIN 75 NM E OF THE COLD FRONT N OF 27N. A SECOND RIDGE AXIS COVERS THE AREA E OF THE ABOVE FRONT ANCHORED BY A 1035 MB HIGH N OF THE AZORES. THE CENTRAL ATLC FRONT WILL CONTINUE TO SHIFT EASTWARD. W ATLC HIGH PRESSURE WILL DRIFT SOUTHWARD BETWEEN 70W AND 75W MON THROUGH WED. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ PAW