000 AXNT20 KNHC 181721 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT WED MAY 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 58W TO THE SOUTH OF 13N THROUGH GUYANA MOVING W AT 10 KT. IT IS EMBEDDED IN A BROAD AREA OF MOISTURE N OF THE ITCZ AS DEPICTED ON THE SSMI TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS FROM 4S-9N BETWEEN 55W-60W. ...THE ITCZ... THE ITCZ AXIS IS FROM 6N10W TO 4N20W 3N40W 1N50W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 2N-6N BETWEEN 10W-13W...FROM 4N-8N BETWEEN 15W-19W...AND FROM 3N-6N BETWEEN 21W-24W. ISOLATED MODERATE CONVECTION IS FROM 3N-6N BETWEEN 30W-38W. ...DISCUSSION... GULF OF MEXICO... A WEAK COLD FRONT EXTENDS FROM COCOA BEACH FLORIDA TO NORTH OF TAMPA FLORIDA TO THE MOUTH OF THE MISSISSIPPI RIVER. NO SIGNIFICANT PRECIPITATION IS NOTED. A SURFACE TROUGH IS OVER THE STRAITS OF FLORIDA FROM 25N80W TO 23N87W. RADAR IMAGERY SHOWS ISOLATED MODERATE CONVECTION FROM 23N-25N BETWEEN 80W-84W. ELSEWHERE...BROKEN LOW CLOUDS ARE W OF 95W. 5-10 KT NORTHERLY WINDS ARE N OF THE FRONT. 5-10 KT SOUTHERLY WINDS ARE S OF THE TROUGH. 15-20 KT SE WINDS ARE OVER THE W GULF OF MEXICO W OF 90W. IN THE UPPER LEVELS... NW FLOW IS OVER THE GULF WITH STRONG SUBSIDENCE...THUS THE AREA IS VOID OF ANY HIGH CLOUD. EXPECT IN 24 HOURS FOR THE FRONT AND SURFACE TROUGH TO MOVE E INTO THE WEST ATLC WITH LINGERING SHOWERS OVER THE STRAITS OF FLORIDA. CARIBBEAN SEA... A SURFACE TROUGH IS OVER EASTERN CARIBBEAN FROM 19N62W TO 10N64W WITH SCATTERED SHOWERS WITHIN 60 NM OF THE AXIS. ANOTHER TROUGH IS OVER THE CENTRAL CARIBBEAN FROM 16N71W TO W VENEZUELA AT 8N72W WITH SCATTERED SHOWERS WITHIN 60 NM OF THE AXIS. SCATTERED SHOWERS ARE ALSO INLAND OVER NICARAGUA...W HONDURAS... AND GUATEMALA. IN THE UPPER LEVELS... THE BASE OF AN UPPER LEVEL TROUGH IS OVER THE CARIBBEAN WITH AXIS ALONG 72W. THIS TROUGH IS SUPPORTING THE SURFACE TROUGHS. STRONG SUBSIDENCE IS OVER THE NW AND NORTH CENTRAL CARIBBEAN. A GOOD AMOUNT OF UPPER LEVEL MOISTURE AND HIGH CLOUD IS ELSEWHERE. EXPECT IN 24 HOURS FOR THE TROUGHS TO MOVE W AT 10 KTS WITH SHOWERS. ALSO EXPECT CONVECTION OVER THE WINDWARD ISLANDS DUE TO THE APPROACHING TROPICAL WAVE. THE ATLANTIC OCEAN... A COLD FRONT IS OVER THE W ATLANTIC FROM 32N78W TO COCOA BEACH FLORIDA. NO PRECIPITATION IS NOTED. A PREFRONTAL TROUGH EXTENDS FROM 32N74W TO THE STRAITS OF FLORIDA AT 25N80W. WIDELY SCATTERED MODERATE CONVECTION IS OVER THE BAHAMAS N OF 25N BETWEEN 73W-78W. A SURFACE TROUGH IS N OF HISPANIOLA FROM 23N68W TO 20N72W WITH SCATTERED SHOWERS WITHIN 30 NM OF THE AXIS. ANOTHER SURFACE TROUGH IS OVER THE CENTRAL ATLC FROM 33N44W TO 25N50W WITH SCATTERED SHOWERS WITHIN 30 NM OF THE AXIS. A SURFACE RIDGE AXIS IS OVER THE E ATLC N OF 10N E OF 42W. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH IS SUPPORTING THE W ATLANTIC FRONT AND SURFACE TROUGH. ANOTHER UPPER LEVEL TROUGH IS OVER THE CENTRAL ATLC SUPPORTING THE CENTRAL ATLANTIC TROUGH. EXPECT OVER THE NEXT 24 HOURS FOR...THE FRONT TO MOVE E OVER THE W ATLC WITH SHOWERS...AND THE CENTRAL ATLANTIC TROUGH TO REMAIN STATIONARY WITH MORE SHOWERS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ FORMOSA/MONTALVO