000 AXNT20 KNHC 160532 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE JUN 16 2009 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...METEOROLOGICAL ANALYSIS...WEATHER OBSERVATIONS...AND RADAR. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0445 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 78W/79W S OF 18N MOVING W NEAR 15 KT. THIS WAVE HAS WEAKENED AS IT NO LONGER COINCIDES WITH A MAXIMUM IN DEEP LAYER MOISTURE IN THE TOTAL PRECIPITABLE WATER IMAGERY. SUBSIDENCE IN NORTHERLY FLOW ALOFT IS LIMITING THE COVERAGE OF DEEP CONVECTION NEAR THIS WAVE. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 12N14W 9N21W 6N30W 3N40W AND INTO NE BRAZIL NEAR 1N52W. LARGE CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE WITHIN 150/200 NM ON BOTH SIDES OF THE AXIS BETWEEN 25W-52W AND INLAND OVER NE SOUTH AMERICA. ...DISCUSSION... GULF OF MEXICO... A SURFACE TROUGH IS OVER THE N FLORIDA PENINSULA EXTENDING FROM NEAR 28N82W TO BEYOND 32N82W CONTINUING N TO A SURFACE LOW OVER SOUTH CAROLINA. UPPER LEVEL DIFFLUENCE OVER THE YUCATAN PENINSULA IS SUPPORTING SCATTERED SHOWERS/THUNDERSTORMS OVER THE YUCATAN PENINSULA AND THE E BAY OF CAMPECHE S OF 21N E OF 95W. ELSEWHERE...FAIR WEATHER PREVAILS AS A STATIONARY 1016 MB SURFACE HIGH LOCATED NEAR 28N87W DOMINATES THE REMAINDER OF THE GULF OF MEXICO. AN UPPER LEVEL RIDGE EXTENDING FROM MEXICO ACROSS THE GULF AND THE FLORIDA PENINSULA IS SUPPORTING THE SURFACE HIGH PROVIDING DRY AIR AND SUBSIDENCE. ANTICYCLONIC FLOW AROUND THE SURFACE HIGH IS AFFECTING MUCH OF THE GULF...WITH SE WINDS OF 15 TO 20 KT OCCURRING ACROSS PORTIONS OF THE W GULF. THE SURFACE HIGH IS FORECAST TO REMAIN OVER THE GULF AND A SURFACE TROUGH CURRENTLY OVER THE W CARIBBEAN IS EXPECTED TO MOVE INTO THE YUCATAN PENINSULA OVER THE NEXT SEVERAL HOURS AND ACROSS THE SOUTHERN GULF TUESDAY AND WEDNESDAY. CARIBBEAN SEA... A SURFACE TROUGH IS IN THE NW CARIBBEAN EXTENDING FROM 21N85W TO 16N87W TO INLAND OVER HONDURAS. LOW LEVEL CONVERGENCE ALONG WITH UPPER LEVEL DIFFLUENCE OVER THE YUCATAN PENINSULA ARE SUPPORTING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ACROSS THE W CARIBBEAN FROM 14N-20N W OF 80W TO INLAND OVER PORTIONS OF CENTRAL AMERICA. ATMOSPHERIC INSTABILITY IS RESULTING IN SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ACROSS HISPANIOLA AND THE ADJACENT COASTAL WATERS. SIMILAR ACTIVITY ACROSS THE LESSER ANTILLES E OF 62W IS SUPPORTED BY AN UPPER LEVEL TROUGH THAT EXTENDS FROM THE CENTRAL ATLC OVER THE FAR E CARIBBEAN. ATLANTIC OCEAN... UPPER LEVEL TROUGHING OVER THE NW ATLC N OF THE DISCUSSION AREA IS SUPPORTING ISOLATED SHOWERS ACROSS THE W ATLC N OF 30N BETWEEN 60W-77W. ISOLATED SHOWERS REMAIN ALONG THE E COAST OF FLORIDA BETWEEN FORT LAUDERDALE AND PALM BEACH...REMNANTS OF LATE AFTERNOON THUNDERSTORMS THAT DEVELOPED ORIGINALLY NEAR LAKE OKEECHOBEE. A BROAD UPPER TROUGH COVERS THE CENTRAL ATLC TO OVER THE FAR E CARIBBEAN WITH AN EMBEDDED UPPER LOW NEAR 28N50W SUPPORTING A WEAK SURFACE TROUGH THAT EXTENDS FROM 27N51W TO 31N49W. UPPER LEVEL DIFFLUENCE TO THE W OF THE UPPER TROUGH IS GENERATING POSSIBLE ISOLATED SHOWERS FROM 24N-28N BETWEEN 62W-68W. AT THE BASE OF THE UPPER TROUGH ARE SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 11N-18N W OF 56W TO OVER THE LESSER ANTILLES. ELSEWHERE ACROSS THE ATLC...A BROAD SURFACE RIDGE ANCHORED BY A 1030 MB HIGH N OF THE DISCUSSION AREA NEAR 35N32W DOMINATES BRINGING FAIR WEATHER ACROSS THE REMAINDER OF THE ATLC. $$ WALTON/WALLACE