000 AXNT20 KNHC 252342 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT WED JUN 25 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 50W S OF 9N MOVING W NEAR 20 KT. WEAK INVERTED-V LOW LEVEL SIGNATURE IS SEEN ON SATELLITE IMAGERY WHILE THE MIMIC-TPW ANIMATION CONTINUES TO SHOW A SMALL SURGE OF MOISTURE IN THE VICINITY OF THIS WAVE. ISOLATED MODERATE CONVECTION IS NEAR THE NORTHERN END OF THE WAVE...AND OVER ILHA DE MARAJO IN BRAZIL. A TROPICAL WAVE EXTENDS FROM THE CAYMAN ISLANDS TO THE SW CARIBBEAN/PANAMA. ITS AXIS ALONG 80W S OF 20N MOVING W 15-20 KT. THE WAVE SHOWS UP VERY WELL ON THE TOTAL PRECIPITABLE WATER WHERE A NORTH-SOUTH MOISTURE MAXIMUM IS OBSERVED. SCATTERED SHOWERS AND TSTMS ARE EITHER SIDE OF THE WAVE AXIS BUT MAINLY SOUTH OF 17N. THE WAVE IS FORECAST TO MOVE ACROSS CENTRAL AMERICA LATE TONIGHT INTO THU ENHANCING SHOWER/TSTM ACTIVITY. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 9N13W 7N25W 5N35W 5N47W INTO NE BRAZIL. CLUSTERS OF MODERATE AND ISOLATED STRONG CONVECTION ARE MOVING OFF THE AFRICAN COAST...LIKELY ASSOCIATED WITH THE NEXT TROPICAL WAVE. SATELLITE IMAGERY SHOWS A BROAD AREA OF CYCLONIC TURNING FROM 5N-10N AND E OF 20W TO THE AFRICAN COAST. THE DAKAR VERTICAL SOUNDING IS SHOWING NW WINDS AT LOW LEVELS...INDICATING THAT THE WAVE HAS NOT CROSS THIS AREA YET. IN SPITE OF THESE INDICATIONS...IT IS NOT ENTIRELY CLEAR WHERE THE WAVE AXIS LIES. FOR THAT REASON...WE WILL WAIT FOR FURTHER DATA BEFORE PLACING THE WAVE. ...DISCUSSION... GULF OF MEXICO... A SHORT-WAVE TROUGH LIES OVER THE GULF STRETCHING FROM LOUISIANA TO THE BAY OF CAMPECHE AND THE ISTHMUS OF TEHUANTEPEC. AN UPPER LEVEL RIDGE EXTENDS FROM THE CARIBBEAN OVER THE REMAINDER OF THE GULF REGION INTO THE W ATLC TO OVER SOUTH FLORIDA AND THE NW BAHAMAS. SWLY FLOW BETWEEN THESE TWO UPPER LEVEL FEATURES ARE SUPPLYING THE E GULF AND FLORIDA WITH ABUNDANCE OF TROPICAL MOISTURE. THESE WINDS ARE ALSO ENHANCING CONVECTION OVER THE YUCATAN PENINSULA AND WESTERN CUBA. LIGHTNING DATA REVEALS SCATTERED TSTMS ACROSS THE YUCATAN PENINSULA AND THE STATE OF FLORIDA. WEAK SURFACE RIDGE EXTENDS FROM THE W ATLC OVER THE GULF WITH A 1023 MB HIGH CENTERED NEAR 29N84W. UNDER THIS PATTERN...E TO SE WINDS OF 10 TO 15 KT ARE BLOWING ACROSS THE GULF WITH A A NARROW BAND OF 15-20 KT OVER THE STRAITS OF FLORIDA AND THE SE PORTION OF THE GULF. THE RIDGE WILL REMAIN IN PLACE THE REST OF THE WORK WEEK. CARIBBEAN... AN UPPER RIDGE ANCHORED IN THE E PACIFIC REGION EXTENDS ACROSS HONDURAS/NICARAGUA AND W/CENTRAL CUBA INTO THE W ATLC TO BEYOND 30N70W. A SECOND UPPER RIDGE ANCHORED E OF THE WINDWARD ISLANDS COVERS THE E CARIBBEAN. A WEAK UPPER TROUGH REMAINS BETWEEN THESE UPPER RIDGES EXTENDING FROM THE W ATLC INTO THE CARIBBEAN SEA THROUGH HISPANIOLA. ABUNDANT UPPER-LEVEL MOISTURE IS BEEN TRANSPORTED FROM NORTHERN SOUTH AMERICA INTO THE E CARIBBEAN. UPPER DIFFLUENCE COUPLED WITH THE TROPICAL WAVE MENTIONED ABOVE IS ENHANCING CONVECTION OVER CENTRAL AMERICA FROM W PANAMA TO HONDURAS AS WELL AS OVER THE GULF OF HONDURAS. CONVECTION HAS ALSO FLARED UP OVER N VENEZUELA AND COLOMBIA LIKELY DUE TO THE PRESENCE OF THE ITCZ AXIS. MODERATE/STRONG EASTERLY TRADE WINDS CONTINUE TO DOMINATE MOST OF THE CARIBBEAN DUE TO THE TIGHT PRESSURE GRADIENT BETWEEN THE SURFACE RIDGE OVER THE ATLC AND LOWER PRESSURE OVER SOUTH AMERICA. ATLANTIC... AN UPPER RIDGE EXTENDS FROM THE CARIBBEAN ACROSS W/CENTRAL CUBA TO OVER THE NW BAHAMAS AND THE W ATLC W OF 70W. AN UPPER-LEVEL LOW NEAR 28N61W HAS A TROUGH THAT EXTENDS SW AND THEN ENTERS THE CARIBBEAN SEA THROUGH HISPANIOLA. LARGE UPPER RIDGE DOMINATES THE REMAINDER OF THE CENTRAL ATLC ANCHORED BY AN UPPER HIGH NEAR 32N44W. AN UPPER TROUGH IS OVER THE E ATLC EXTENDING THROUGH 32N28W TO 22N47W. UPPER HIGH IS E OF THE WINDWARD ISLANDS NEAR 13N54W WITH THE RIDGE COVERING THE EASTERN CARIBBEAN TO THE WEST. ANOTHER UPPER-LEVEL HIGH CENTERED JUST E OF THE CANARY ISLANDS EXTENDS A RIDGE SW TO THE CAPE VERDE ISLANDS. A SURFACE RIDGE DOMINATES THE ENTIRE ATLC FORECAST AREA ANCHORED BY A 1026 MB HIGH CENTERED NEAR 29N58W. A MOSTLY DRY AND STABLE ATMOSPHERE IS ASSOCIATED WITH THIS RIDGE WHICH IS ALSO PRODUCING A WIDE SWATH OF MODERATE TO STRONG ELY FLOW ACROSS THE N TROPICAL ATLC INTO THE CARIBBEAN SEA. THIS HIGH WILL REMAIN NEARLY STATIONARY AND SLIGHTLY WEAKEN DURING THE NEXT 24 HOURS. $$ GR