000 AXNT20 KNHC 131739 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT FRI JUN 13 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1715 UTC. ...TROPICAL WAVES... A TROPICAL IS APPROACHING THE CAPE VERDE ISLANDS WHERE NE WINDS ARE BLOWING AT THIS TIME. IT AXIS IS ALONG 23W S OF 17N MOVING W 10-15 KT. A FEW CELLS ARE NOTED WHERE THE TROPICAL WAVE MEETS THE ITCZ WITH A BAND OF LOW/MID CLOUDS JUST BEHIND THE WAVE AXIS. SFC DATA...SATELLITE IMAGERY AND THE SSMI-DERIVED TPW SUPPORT THE POSITION OF THE WAVE AXIS. A TROPICAL WAVE IS OVER THE FAR EASTERN CARIBBEAN ALONG 62W S OF 18N MOVING W 15-20 KT. THE WAVE IS WELL DEPICTED IN THE MOISTURE PRODUCTS AND E CARIBBEAN ISLANDS SURFACE OBSERVATIONS. BARBADOS REPORTED THIS MORNING 2.93 INCHES OF RAIN IN 24 HOURS...AND MARTINIQUE ALSO REPORTED HEAVY RAIN AT TIMES AND GUSTY WINDS OF 33 KT WITH THE PASSAGE OF THE WAVE. SCATTERED SHOWERS AND ISOLATED TSTMS ARE NOTED OVER THE LESSER ANTILLES PARTICULARLY BETWEEN GUADELOUPE AND ST. LUCIA. THIS TROPICAL WAVE IS FORECAST BY THE COMPUTER MODELS TO MOVE OVER THE UK/US VIRGIN ISLANDS AND PUERTO RICO TONIGHT INCREASING THE LIKELIHOOD OF SHOWERS AND TSTMS. ALSO...IT IS EXPECTED TO REACH DOMINICAN REPUBLIC SATURDAY MORNING. A WEAK TROPICAL WAVE EXTENDS FROM THE EASTERN TIP OF DOMINICAN REPUBLIC TO CURACAO ALONG 69W. THE WAVE STILL SHOWS UP ON VIS SATELLITE PICTURES WHERE AN INVERTED-V PATTERN IS OBSERVED. YESTERDAY...THE SAN JUAN VERTICAL SOUNDING SHOWED CLEARLY THE PASSAGE OF THE WAVE AXIS WITH DEEP TROPICAL MOISTURE UP TO 700 MB AND SE WINDS AT LOW LEVELS. THIS FEATURE WILL ENHANCE SOME SHOWER/TSTM ACTIVITY OVER HISPANIOLA THIS AFTERNOON AND TONIGHT AND IS EXPECTED TO WEAKEN FURTHER OVER THE WESTERN CARIBBEAN ON SAT. SCATTRED SHOWERS AND ISOLATED TSTMS ARE NEAR THE N END OF THE WAVE AXIS AND CLOSE TO 16N70W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N13W 10N22W 7N27W 3N40W 2N52W. MODERATE/ISOLATED STRONG CONVECTION IS NOTED WITHIN 100 NM N OF AXIS BETWEEN 30W-40W...AND WITHIN 125 NM N OF AXIS BETWEEN 46W-51W. SIMILAR CONVECTION IS FROM 4N-6N EAST 14W TO THE AFRICAN COAST. ...DISCUSSION... GULF OF MEXICO... A MID/UPPER LEVEL CYCLONE IS CENTERED NEAR 22N94W. AS OF 1500 UTC...A SFC TROUGH...REFLECTION OF THIS CLOSED LOW IS ANALYZED OVER THE SW GULF AND RUNS FROM 22N96W TO 18N94W. EAST OF THE UPPER LOW...AN UPPER-LEVEL RIDGE ANCHORED ON HIGH OVER THE GULF OF HONDURAS EXTENDS N ACROSS THE EASTERN GULF OF MEXICO. UNDER THIS WEATHER PATTERN...A FAIR AMOUNT OF CLOUDINESS WITH EMBEDDED SHOWERS AND TSTMS IS MAINLY OVER THE WESTERN HALF OF THE GULF WHILE ANOTHER AREA OF SCATTERED SHOWERS AND TSTMS IS VERY CLOSE TO THE FLORIDA PANHANDLE. A 1023 MB SFC HIGH OVER THE SE CONUS ENVELOPS THE EASTERN GULF AND THE STATE OF FLORIDA. PRES GRADIENT BETWEEN THE SFC HIGH AND THE TROUGH OVER THE SW GULF IS PRODUCING MODERATE TO OCCASIONALLY FRESH SE WINDS OVER PARTS OF THE CENTRAL AND WESTERN GULF. THESE WINDS ARE EXPECTED TO DIMINISH LATE TODAY INTO THIS EVENING. CARIBBEAN... A PAIR OF TROPICAL WAVES ARE MOVING WWD ACROSS THE EASTERN CARIBBEAN. SEE TROPICAL WAVE SECTION FOR MORE DETAILS. EXPECT AN INCREASE IN WINDS AND SEAS TO ACCOMPANY THE PASSAGE OF BOTH WAVES. AN EARLIER QSCAT PASS SHOWED SOME WIND BARS OF 25 TO 30 KT OVER PARTS OF THE EASTERN AND CENTRAL CARIBBEAN BUT MAINLY NEAR THE COLOMBIAN COAST. HIGH PRES BUILDING INTO THE EASTERN CARIBBEAN LATE THIS WEEKEND SHOULD BRING FRESH TO STRONG TRADES BY EARLY NEXT WEEK. THE NWW3 ENSEMBLE SUGGESTS A LARGE AREA OF ELY WINDS OF 25 KT OVER THE E AND CENTRAL CARIBBEAN ON MON. ALOFT...A RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE BASIN. A BROAD UPPER TROUGH EXTENDING FROM AN UPPER-LEVEL LOW LOCATED JUST E OF THE BAHAMAS DIPS S OVER THE N CENTRAL CARIBBEAN. UPPER DIFFLUENCE BETWEEN THIS TROUGH AND AN UPPER HIGH SITUATED EAST OF THE LESSER IS HELPING TO INDUCE THE CONVECTIVE ACTIVITY ASSOCIATED WITH THE ABOVE MENTIONED TROPICAL WAVES. SCATTRED MODERATE CONVECTION IS OVER PARTS OF PANAMA AND COSTA RICA...LIKELY ASSOCIATED WITH THE CLOSE PROXIMITY OF THE EPAC ITCZ AND A DIFFLUENT PATTERN ALOFT. ATLANTIC... THE MID/UPPER LEVEL LOW THAT WAS GENERATING STRONG TSTMS OVER THE STATE OF FLORIDA DURING THE LAST FEW DAYS HAS MOVED SE ACROSS THE W ATLC AND IS NOW LOCATED JUST EAST OF THE NW BAHAMAS NEAR 27N76W. THIS LOW HAS A TROUGH EXTENDING S ACROSS THE SE BAHAMAS INTO THE CENTRAL CARIBBEAN. A FEW HEAVY SHOWERS AND TSTMS ARE STILL FLARING OVER FLORIDA AND THE BAHAMAS AROUND THE CYCLONIC FLOW ASSOCIATED WITH THIS FEATURE. THE SUBTROPICAL CENTRAL ATLC IS DOMINATED BY THE SOUTHERN END OF A LONG WAVE TROUGH WHICH IS SUPPORTING A STATIONARY FRONT EXTENDING ALONG 30N34W 28N55W 25N72W. A BROKEN BAND OF LOW/MID CLOUDS WITH EMBEDDED SHOWERS AND ISOLATED TSTMS IS RELATED TO THIS FRONTAL SYSTEM. A SECOND COLD FRONT IS APPROACHING THE AREA AND IS CURRENTLY PASSING THROUGH BERMUDA WITH A WELL DEFINED BAND OF CLOUDS. THE UPPER LEVELS OF THE SUBTROPICAL EASTERN ATLC IS DOMINATED BY A RIDGE. IN THE TROPICS...AN UPPER LEVEL HIGH IS CENTERED NEAR 14N55W WITH THE ANTICYCLONIC FLOW REACHING THE SE CARIBBEAN TO THE WEST AND THE CAPE VERDE ISLANDS TO THE EAST. UPPER DIFFLUENCE ASSOCIATED WITH THIS SYSTEM IS ENHANCING CONVECTION ALONG THE ITCZ. $$ GR