000 AXNT20 KNHC 180007 TWDAT TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE MAY 17 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... AS OF 21 UTC...AN ATLANTIC OCEAN TROPICAL WAVE IS NEAR 54W AND S OF 9N THROUGH FRENCH GUIANA MOVING W AT 5 KT. IT IS EMBEDDED IN A BROAD AREA OF MOISTURE N OF THE ITCZ AS DEPICTED ON THE SSMI TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED TO ISOLATED MODERATE TO STRONG CONVECTION IS WITHIN 100 NM EITHER SIDE OF THE AXIS. ...ITCZ... A MONSOON TROUGH IS OVER THE EASTERN TROPICAL ATLANTIC FROM 8N12W WEST-SOUTHWESTWARD TO 4N18W. AS OF 21 UTC...ISOLATED MODERATE CONVECTION IS S OF THE TROUGH AXIS FROM EQ-3N BETWEEN 13W-16W. THE ITCZ CONTINUES FROM 4N18W 3N30W EQ40W TO N BRAZIL AT 2S48W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 2N-6N BETWEEN 25W-28W. ...DISCUSSION... GULF OF MEXICO... A QUASI-STATIONARY 1002 MB LOW IS CENTERED OVER NORTH CAROLINA NEAR 36N80W. A SURFACE TROUGH EXTENDS S FROM THE LOW TO SOUTHERN FLORIDA AT 26N80W AND EXTENDS SW TO THE E GULF OF MEXICO AT 24N84W. AS OF 21 UTC...NO SHOWERS ARE OBSERVED FOR THE PORTION OF THE TROUGH OVER THE GULF. THE REMAINDER OF THE GULF HAS MOSTLY FAIR WEATHER ASSOCIATED TO RIDGING FROM A 1011 MB HIGH PRESSURE THAT ENTERS THE AREA NEAR 29N93W. LIGHT WINDS PREVAIL THROUGHOUT THE GULF FROM 10-15 KTS. IN THE UPPER LEVELS...AN UPPER LEVEL TROUGH WITH AXIS NOW NEAR 75W SUPPORTS THE SURFACE TROUGH. STRONG SUBSIDENCE COVERS THE ENTIRE GULF...THUS THE AREA IS VOID OF ANY HIGH CLOUD. EXPECT IN 24 HOURS FOR THE SURFACE TROUGH TO DRIFT SE WITH POSSIBLE LIGHT SHOWERS. ALSO EXPECT FOR THE HIGH TO MOVE TO THE NORTH EASTERN GULF KEEPING RIDGING AND FAIR WEATHER CONDITIONS IN THE REGION. CARIBBEAN SEA... A SURFACE TROUGH IS OVER HAITI AND THE CENTRAL CARIBBEAN ALONG 72W FROM 14N-20N...SCATTERED SHOWERS ARE OVER HISPANIOLA. THE TAIL END OF A SURFACE TROUGH REACHES NORTHERN PUERTO RICO FROM THE CENTRAL ATLANTIC. THE RADAR SHOWS THAT SCATTERED SHOWERS AND LOCALIZED THUNDERSTORMS ARE OVER PUERTO RICO...AND THE VIRGIN ISLANDS. IN THE UPPER LEVELS...A TROUGH WITH AXIS NEAR 75W IS SUPPORTING BOTH SURFACE TROUGHS IN THE CARIBBEAN. STRONG SUBSIDENCE IS OVER THE NW AND CENTRAL CARIBBEAN. EXPECT IN 24 HOURS FOR A SURFACE TROUGH TO BE OVER EAST-CENTRAL CUBA...ALSO EXPECT CONTINUED SHOWERS OVER THE CENTRAL AND EASTERN CARIBBEAN...AND NORTHERN SOUTH AMERICA. ATLANTIC OCEAN... A STATIONARY FRONT IS OVER THE W ATLANTIC FROM 30N72W TO THE BAHAMAS ALONG 27N73W 24N76W. AS OF 21 UTC NO SIGNIFICANT CONVECTION IS ASSOCIATED TO THIS FRONT. A SURFACE TROUGH IS BEHIND THIS FRONT ALONG 30N77W TO SOUTHERN FLORIDA NEAR 26N80W. THE RADAR SHOWS SHOWERS AND ISOLATED THUNDERSTORMS OVER AND TO THE SW OF FREEPORT. A LONG SURFACE TROUGH IS OVER THE CENTRAL ATLANTIC FROM 30N45W TO 23N53W TO N OF PUERTO RICO NEAR 18N66W. THE RADAR SHOWS THAT SCATTERED SHOWERS AND LOCALIZED THUNDERSTORMS ARE OVER PUERTO RICO...S OF PUERTO RICO AND ALSO THE VIRGIN ISLANDS. SCATTERED SHOWERS ARE WITHIN 180 NM EITHER SIDE OF THE REMAINDER OF THE TROUGH. A SURFACE TROUGH IS OVER THE E ATLANTIC N OF 27N E OF 12W. IN THE UPPER LEVELS...A TROUGH IS SUPPORTING THE W ATLANTIC FRONT AND TROUGH AND THE CENTRAL TROUGH. ANOTHER UPPER LEVEL TROUGH IS OVER THE EASTERN ATLANTIC SUPPORTING THE TROUGH N OF 27N. EXPECT OVER THE NEXT 24 HOURS FOR...THE CENTRAL ATLANTIC TROUGH TO REMAIN QUASI-STATIONARY WITH MORE SHOWERS. FOR ADDITIONAL INFORMATION PLEASE VISIT HTTP://WWW.HURRICANES.GOV/MARINE $$ NAR