000 AXNT20 KNHC 192356 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT TUE JUN 19 2007 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHERN SECTIONS OF SOUTH AMERICA...AND THE 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 32W S OF 12N MOVING WEST 15 KT. ISOLATED MODERATE CONVECTION IS NOTED MAINLY WITHIN THE ITCZ. A WELL DEFINED TROPICAL WAVE IS ALONG 62W SOUTH OF 16N MOVING WEST 15 KT. THIS TROPICAL WAVE MOVED INTO THE EASTERN CARIBBEAN THIS MORNING GENERATING SOME SHOWER ACTIVITY...HEAVY AT TIMES OVER THE WINDWARD ISLANDS. SCATTERED MODERATE CONVECTION IS FROM 12N-15N BETWEEN 58W-65W. MOISTURE FROM THIS WAVE SHOULD BEGIN TO AFFECT THE VIRGIN ISLANDS AND THEN PUERTO RICO ON WED. A WIND SURGE WILL FOLLOW THE WAVE ALLOWING THE TRADE WINDS TO INCREASE THU THROUGH SAT. A TROPICAL WAVE IS ALONG 86W S OF 15N MOVING WEST 10 TO 15 KT. THIS WAVE IS PRODUCING SCATTERED MODERATE CONVECTION OVER PARTS OF NICARAGUA AND HONDURAS. THE WAVE AXIS EXTENDS SOUTH INTO THE EPAC. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 8N14W 7N25W 5N40W 5N50W 7N60W. CLUSTERS OF MODERATE CONVECTION ARE MOVING OFF THE AFRICAN COAST FROM 10N-15N. SIMILAR CONVECTION IS NOTED WITHIN 60 NM MAINLY N OF THE ITCZ AXIS E OF 23W. WIDELY SCATTERED MODERATE CONVECTION IS ALONG THE AXIS BETWEEN 33W-48W. ...DISCUSSION... THE GULF OF MEXICO... A 1024 HIGH IS CENTERED OVER THE W ATLANTIC NEAR 29N72W. HIGH PRESSURE RETURN FLOW OF 10 TO 20 KT FROM THIS HIGH DOMINATES THE GULF OF MEXICO. THE STRONGEST WINDS ARE FOUND OVER THE SW GULF. THIS MOIST ONSHORE FLOW ALONG WITH A SHORT WAVE TROUGH CURRENTLY OVER ALABAMA IS ENHANCING SCATTERED TO NUMEROUS SHOWERS AND TSTMS FROM E TEXAS TO N FLORIDA. DIFFLUENCE ASSOCIATED WITH AN UPPER RIDGE THAT COVERS THE ENTIRE GULF AND THE SE U.S. IS ALSO SUPPORTING THIS CONVECTIVE ACTIVITY. THE RIDGE IS ANCHORED ON A HIGH LOCATED OVER E-CENTRAL MEXICO. ANTICYCLONIC FLOW COVERS THE ENTIRE AREA. MOSAIC DOPPLER RADAR FROM THE SE U.S. SHOWS SCATTERED SHOWERS AND ISOLATED TSTMS JUST WEST OF KEY WEST IN THE FLORIDA KEYS...AND A LINE OF STRONG TSTMS MOVING INTO THE NORTHERN GULF WATERS FROM THE SE U.S.. THESE TSTMS ARE N OF 29N BETWEEN 85W-89W. A SURFACE LOW IS EXPECTED TO DEVELOP OVER S GEORGIA NEAR 32N82W IN 24 HOURS DRAGGING A SFC TROUGH INTO THE NORTHERN GULF WATERS ON THU. THE CARIBBEAN SEA... A DRY AND STABLE AIRMASS DOMINATES THE W CARIBBEAN WITH 20 KT TRADEWINDS AND MOSTLY FAIR WEATHER. SCATTERED SHOWERS AND ISOLATED TSTMS ARE HOWEVER OVER PANAMA AND COSTA RICA DUE TO THE PRESENCE OF THE ITCZ AXIS. THE E CARIBBEAN E OF 75W HAS TROPICAL MOISTURE ASSOCIATED WITH A TROPICAL WAVE. SEE ABOVE. IN THE UPPER LEVELS...THE UPPER LEVEL HIGH OVER E-CENTRAL MEXICO IS PRODUCING NLY FLOW OVER THE W CARIBBEAN W OF 80W. ANOTHER UPPER LEVEL HIGH IS CENTERED E OF THE WINDWARD ISLANDS NEAR 14N54W. SWLY WINDS ON THE WESTERN SIDE OF THIS UPPER HIGH ARE TRANSPORTING UPPER LEVEL MOISTURE/HIGH CLOUDS FROM NORTHERN SOUTH AMERICA INTO THE E CARIBBEAN. AN UPPER TROUGH EXTENDS FROM E CUBA TO COSTA RICA TRIGGERING SOME CONVECTIVE ACTIVITY OVER E CUBA...JAMAICA AND THE WINDWARD PASSAGE. CLUSTERS OF MODERATE CONVECTION ARE SEEN OVER NORTHERN VENEZUELA AND COLOMBIA DUE TO THE ITCZ AXIS ALONG 9N. THE ATLANTIC OCEAN... A SFC RIDGE DOMINATES MOST OF THE FORECAST AREA WITH A COUPLE OF HIGHS CENTERED NEAR 29N72W AND 26N48W. THE FIRST ONE WILL DISSIPATE IN 24 HOURS WHILE THE SECOND ONE WILL REMAIN NEARLY STATIONARY. A 1016 MB LOW IS FURTHER E OVER THE E ATLANTIC NEAR 27N34W. A SURFACE TROUGH EXTENDS SW FROM THE LOW TO NEAR 21N35W. MAINLY LOW LEVEL CLOUDS ARE ASSOCIATED WITH THE LOW/TROUGH. ANOTHER SFC TROUGH ENTERS THE AREA NEAR 31N55W THEN CONTINUES SW TO 25N62W. SHOWER ACTIVITY AHEAD OF THIS TROUGH HAS DIMINISHED. IN THE UPPER LEVELS...NLY FLOW ASSOCIATED WITH THE UPPER RIDGE OVER THE GULF OF MEXICO ALSO COVERS THE FLORIDA PENINSULA AND THE W ATLANTIC W OF 75W. A BROAD TROUGH PERSISTS OVER THE W-CENTRAL ATLANTIC N OF 24N BETWEEN 45W-75W. A SMALL UPPER LEVEL RIDGE IS ALONG 35W. ANOTHER TROUGH IS OVER THE E ATLANTIC N OF 20N AND E OF 35W. $$ GR