000 AXNT20 KNHC 200545 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT FRI JUN 20 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 22W S OF 12N MOVING W 10-15 KT. THE WAVE SHOWS UP VERY WELL ON THE TPW PRODUCT AND THE HOVMOLLER DIAGRAM. LOW LEVEL SATELLITE DERIVED WINDS ALSO SUPPORTS THE POSITION OF THE WAVE AXIS WHICH EXHIBITS SOME CYCLONIC TURNING NEAR 7N. CONVECTION HAS INCREASED SINCE YESTERDAY AFTERNOON AND NOW SATELLITE IMAGERY REVEALS CLUSTERS OF MODERATE TO ISOLATED STRONG CONVECTION MAINLY AHEAD OF THE WAVE AXIS FROM 3N-11N BETWEEN 21W-26W. A TROPICAL WAVE IS ALONG 59W/60W S OF 19N MOVING W NEAR 20 KT. A BROAD AREA OF CYCLONIC TURNING IS ASSOCIATED WITH THE WAVE. SFC OBSERVATIONS FROM THE LESSER ANTILLES INDICATES THAT THE WAVE ALREADY CROSSED BARBADOS WHICH IS REPORTING SE WINDS 20 KT AND MAINLY LIGHT SHOWERS. PRESSURES ARE FALLING 2 MB AHEAD OF THE WAVE AXIS. THE WAVE IS GENERATING SCATTERED SHOWERS AND TSTMS OVER THOSE ISLANDS BUT MAINLY BETWEEN GUADELOUPE AND DOMINICA. THE MIMIC-TPW PRODUCT SHOWS THE WAVE VERY WELL WHERE A GOOD SURGE OF MOISTURE IS NOTED. MOISTURE ASSOCIATED WITH THIS WAVE IS EXPECTED TO REACH THE UK/US VIRGIN ISLANDS THIS MORNING AND PUERTO RICO THROUGHOUT THE DAY...BRINGING AN INCREASE IN SHOWER ACTIVITY AND GUSTY WINDS. ...ITCZ... THE ITCZ IS PRETTY ACTIVE TONIGHT. ITS AXIS IS CENTERED ALONG 10N14W 6N20W 5N30W 2N40W INTO NRN BRAZIL NEAR 2N51W. CLUSTERS OF SCATTERED MODERATE TO ISOLATED STRONG CONVECTION ARE FROM THE EQUATOR TO 5N BETWEEN 26W-51W. ...DISCUSSION... GULF OF MEXICO... AN UPPER TROUGH IS OVER THE WESTERN HALF OF THE GULF EXTENDING FROM A CLOSED LOW NEAR 25N93W TO THE BAY OF CAMPECHE. AN UPPER LEVEL RIDGE...ANCHORED ON A HIGH OVER CENTRAL AMERICA IS BUILDING OVER THE EASTERN HALF OF THE GULF REGION. A SWATH OF UPPER LEVEL MOISTURE IS BETWEEN THESE UPPER LEVEL FEATURES OVER THE YUCATAN PENINSULA AND THE SE GULF. AT THE SURFACE...A STATIONARY FRONT REMAINS OVER THE N GULF STATES WHILE A WEAK RIDGE DOMINATES THE REMAINDER OF THE AREA WITH MOSTLY FAIR WEATHER AND LIGHT WINDS. DIFFLUENCE ALOFT ON THE SE SIDE OF THE UPPER TROUGH IS AIDING IN SCATTERED SHOWERS AND TSTMS ACROSS THE THE EASTERN PORTION OF THE BAY OF CAMPECHE...THE YUCATAN PENINSULA AND THE SE GULF. CARIBBEAN... A RIDGE/TROUGH PATTERN IS OBSERVED OVER THE CARIBBEAN SEA. THE RIDGE COVERS THE WEST AND CENTRAL CARIBBEAN WHILE AN UPPER-LEVEL TROUGH FROM THE CENTRAL ATLC HAS ITS BASE OVER THE FAR SE CARIBBEAN AND THE WINDWARD ISLANDS. THE TROPICAL WAVE OVER THE LESSER ANTILLES IS INTERACTING WITH THIS UPPER-LEVEL TROUGH. AS A RESULTS...CONVECTION HAS SLIGHTLY INCREASED NEAR THE NORTHERN END OF THE WAVE AXIS. UPPER DIFFLUENCE BETWEEN AN UPPER-LEVEL TROUGH OVER THE EASTERN SEABOARD AND THE RIDGE OVER THE CARIBBEAN IS HELPING TO INDUCE SOME SHOWER ACTIVITY OVER WESTERN CUBA AND THE STRAITS OF FLORIDA. SOME SHOWER ACTIVITY IS ALSO NOTED OVER N CENTRAL AMERICA. THE ATLC RIDGE WILL BUILD SW OVER THE AREA AND STRENGTHEN THROUGH MON PRODUCING MODERATE TO FRESH TRADE WINDS ACROSS THE BASIN WITH THE STRONGEST WINDS UP TO 30 KT OVER THE SOUTH-CENTRAL CARIBBEAN. ATLANTIC... A BROAD UPPER TROUGH IS OVER THE EASTERN U.S. WHILE AN UPPER RIDGE EXTENDS FROM THE CARIBBEAN ALL THE WAY NE TO BEYOND 31N58W. UPPER DIFFLUENT BETWEEN THESE TWO UPPER LEVEL FEATURES IS ASSISTING IN THE DEVELOPMENT OF SCATTERED SHOWERS AND TSTMS OVER THE STRAITS OF FLORIDA AND JUST E OF THE CENTRAL BAHAMAS FROM 24N-28N BETWEEN 70W-75W. A 1013 MB LOW IS LOCATED OFFSHORE OF THE CAROLINAS NEAR 34N7OW WITH ASSOCIATED FRONTAL BOUNDARY CLIPPING THE W ATLC W OF 74W TO S GEORGIA. AN UPPER LEVEL TROUGH EXTENDS OVER THE E-CENTRAL ATLC WITH THE BASE REACHING THE FAR SE CARIBBEAN AND THE WINDWARD ISLANDS. AN UPPER-LEVEL RIDGE DOMINATES MOST OF THE TROPICS AND IS ENHANCING CONVECTION ALONG THE ITCZ AXIS TONIGHT. HIGH PRES IS IN CONTROL OF THE FORECAST AREA EXTENDING A RIDGE WWD TO EASTERN CUBA. THIS SYSTEM IS FORECAST BY THE COMPUTER MODELS TO STRENGTHEN THROUGH MON PRODUCING A BELT OF MODERATE TO FRESH ELY WINDS AROUND ITS SOUTHERN PERIPHERY FROM THE AFRICAN COAST TO THE EASTERN CARIBBEAN. $$ GR/CW