000 AXNT20 KNHC 170543 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE JUN 17 2008 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 33W S OF 11N MOVING W NEAR 15-20 KT. WELL DEFINED MID LEVEL CYCLONIC CIRCULATION REMAINS ALONG THE WAVE NEAR 7N. LOW LEVEL SATELLITE DERIVED WINDS AND 850 MB VORTICITY ALSO CONFIRM THE POSITION OF THE WAVE AXIS. SCATTERED MODERATE CONVECTION IS WITHIN 100 NM W OF THE WAVE AXIS FROM 8N-11N. MOISTURE FROM THIS TROPICAL WAVE IS FORECAST BY THE COMPUTER MODELS TO REACH THE LESSER ANTILLES ON THU. TROPICAL WAVE IS ALONG 49W S OF 15N MOVING W NEAR 20 KT. THE WAVE SHOWS SOME INVERTED-V CLOUD PATTERN AND THERE IS STILL NO ASSOCIATED DEEP CONVECTION. THE SAHARAN AIR LAYER FROM CIMSS INDICATES THAT THE WAVE REMAINS AT THE LEADING EDGE OF A EXTENSIVE AREA OF AFRICAN DUST. TROPICAL WAVE IS OVER CENTRAL AMERICA ALONG 84W/85W S OF 21N MOVING W AT 10-15 KT. THE WAVE IS EMBEDDED IN AN AREA OF DEEP LAYERED MOISTURE AS DEPICTED ON THE TPW PRODUCT. THIS FEATURE IS ONLY GENERATING ISOLATED SHOWERS AND TSTMS OVER HONDURAS AND NICARAGUA. ...ITCZ... THE ITCZ AXIS IS CENTERED ALONG 7N12W 9N25W 7N31W 5N40W 6N58W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 6N-8N BETWEEN 50W-56W. SIMILAR CONVECTION IS NEAR 7N13W... AND NEAR 6N20W. ...DISCUSSION... GULF OF MEXICO... AN UPPER-LEVEL TROUGH EXTENDS FROM OVER THE SE CONUS TO THE SW PORTION OF THE GULF. A BROAD UPPER RIDGE REMAINS ANCHORED OVER NORTH/CENTRAL MEXICO COVERING THE NW CORNER OF THE GULF WITH MODERATE TO STRONG SUBSIDENCE. SW UPPER LEVEL WINDS AHEAD OF THE TROUGH ARE HELPING TO INDUCE SCATTERED SHOWERS AND TSTMS OVER THE YUCATAN PENINSULA AND WESTERN CUBA. AT THE SURFACE...A WEAK RIDGE...WITH A 1014 MB HIGH NEAR 27N91W IS IN CONTROL OF THE WEATHER PATTERN ACROSS THE GULF GIVING THE AREA MAINLY LIGHT WINDS. THE EXCEPTION IS THE WESTERN GULF WHERE SE TO S WINDS OF 10-15 KT ARE BLOWING. THE RIDGE IS EXPECTED TO PERSIST DURING THE NEXT SEVERAL DAYS WITH A WEAK COLD FRONT CLIPPING THE NE PORTION OF THE GULF LATE. MOSTLY FAIR WEATHER IS NOTED OVER THE GULF UNDER THE INFLUENCE OF THE RIDGE. CARIBBEAN... A BROAD UPPER RIDGE DOMINATES THE CARIBBEAN ANCHORED ON A HIGH OVER NICARAGUA. SWLY WINDS BETWEEN THIS HIGH AND THE UPPER TROUGH THAT LIES OVER THE GULF ARE TRANSPORTING ABUNDANT UPPER LEVEL MOISTURE FROM THE EPAC THROUGH CENTRAL AMERICA INTO THE MW CARIBBEAN AND CUBA. THESE WINDS ARE SUPPORTING THE DEVELOPMENT OF SOME CONVECTIVE ACTIVITY OVER CUBA AND THE BAHAMAS. LIGHTNING DATA REVEALS SCATTERED TSTMS OVER PARTS OF WEST AND CENTRAL CUBA...THE CAYMAN ISLANDS AND THE BAHAMAS. A TROPICAL WAVE IS MOVING WWD OVER CENTRAL AMERICA. SEE TROPICAL WAVE SECTION FOR DETAILS. BROAD UPPER RIDGE FROM THE TROPICAL ATLC COVERS THE E CARIBBEAN WITH STRONG SUBSIDENCE AND DRY AIR. MODERATE TO FRESH TRADE WINDS OF 20-30 KT ARE BLOWING ACROSS THE CENTRAL CARIBBEAN DUE TO TIGHT PRES GRADIENT BETWEEN THE ATLC RIDGE AND THE COLOMBIAN LOW. ATLANTIC... NEARLY ZONAL FLOW DOMINATES THE W AND CENTRAL ATLC ADVECTING ABUNDANT UPPER LEVEL MOISTURE. AS A RESULTS...SOME CLOUDINESS WITH POSSIBLE SHOWERS ARE OBSERVED IN THIS AREA. A DEEP LAYERED TROUGH IS N OF THE REGION SUPPORTING A SFC TROUGH...REMNANTS OF A FRONTAL BOUNDARY...THAT RUNS FROM 32N39W TO 29N44W. A SMALL AREA OF MODERATE CONVECTION IS NEAR THE SOUTHERN END OF THE TROUGH. AN UPPER-LEVEL LOW IS OVER THE E ATLC NEAR 28N22W. A TROUGH EXTENDS FROM THIS LOW INTO THE TROPICS NEAR 14N30W. BROAD UPPER E/W RIDGE DOMINATES THE TROPICS S OF 20N AND WEST OF 35W TO OVER THE E CARIBBEAN. A BROAD BUT WEAK SURFACE RIDGE DOMINATES THE ATLC ANCHORED BY A 1025 MB HIGH IN THE E ATLC NEAR 30N34W. THIS SYSTEM WILL REMAIN NEARLY STATIONARY DURING THE NEXT 24 HOURS. $$ GR/CW