000 AXNT20 KNHC 260543 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT THU JUN 26 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 51W S OF 10N MOVING W NEAR 15-20 KT. WEAK INVERTED-V LOW LEVEL SIGNATURE IS SEEN ON SATELLITE IMAGERY WHILE THE MIMIC-TPW ANIMATION CONTINUES TO SHOW A SMALL LOW-AMPLITUDE BULGE OF MOISTURE IN THE VICINITY OF THIS WAVE. ISOLATED MODERATE CONVECTION IS NEAR THE NORTHERN END OF THE WAVE BETWEEN 49W-52W. A TROPICAL WAVE EXTENDS FROM THE CAYMAN ISLANDS TO THE SW CARIBBEAN AND WRN PANAMA. ITS AXIS IS ALONG 81W/82W 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 W OF THE WAVE AXIS MAINLY SOUTH OF 17N ACROSS ERN HONDURAS/NICARAGUA AND COSTA RICA. THE WAVE IS FORECAST TO MOVE ACROSS CENTRAL AMERICA THROUGH FRI ENHANCING SCATTERED SHOWER AND TSTM ACTIVITY. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 10N13W 5N30W 4N48W 5N47W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 9N-13N BETWEEN 15W-20W. ISOLATED MODERATE CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 20W-27W. SCATTERED MODERATE CONVECTION IS WITHIN 50 NM OF A LINE FROM 9N41W TO 9N48W. ...DISCUSSION... GULF OF MEXICO... A SHORTWAVE TROUGH CONTINUES TO LIE OVER THE GULF STRETCHING FROM THE MISSISSIPPI RIVER DELTA AREA IN LOUISIANA TO THE BAY OF CAMPECHE AND THE ISTHMUS OF TEHUANTEPEC. AN UPPER LEVEL RIDGE EXTENDS FROM THE NW CARIBBEAN OVER THE REMAINDER OF THE GULF REGION INTO THE W ATLC TO OVER SOUTH FLORIDA AND THE NW BAHAMAS. SWLY UPPER FLOW BETWEEN THESE TWO UPPER LEVEL FEATURES IS SUPPLYING THE E GULF AND FLORIDA WITH AN ABUNDANCE OF TROPICAL MOISTURE. THESE DIFFLUENT UPPER WINDS ARE ALSO ENHANCING CONVECTION OVER THE YUCATAN PENINSULA AND SERN GULF WATERS. LIGHTNING DATA INDICATES SCATTERED TSTMS ACROSS THE YUCATAN PENINSULA EXTENDING NORTHEASTWARD ACROSS THE SE GULF AND SRN FLORIDA. A WEAK SURFACE RIDGE EXTENDS FROM THE W ATLC OVER NRN FLORIDA AND THE NRN GULF WITH A 1024 MB HIGH CENTERED NEAR 30N82W. UNDER THIS PATTERN...E TO SE WINDS OF 10-15 KT ARE OBSERVED ACROSS THE GULF WITH A NARROW BAND OF 15-20 KT OVER THE STRAITS OF FLORIDA AND THE SE PORTION OF THE GULF. THE SURFACE RIDGE IS FORECAST TO REMAIN IN PLACE THROUGH THE WEEKEND. CARIBBEAN... AN UPPER RIDGE ANCHORED IN THE E PACIFIC REGION EXTENDS ACROSS HONDURAS/NICARAGUA AND WRN CUBA INTO THE W ATLC TO BEYOND 30N75W. A SECOND UPPER RIDGE ANCHORED E OF THE WINDWARD ISLANDS COVERS THE ERN 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 BEING TRANSPORTED FROM NRN SOUTH AMERICA INTO THE E CARIBBEAN. UPPER DIFFLUENCE COUPLED WITH THE TROPICAL WAVE ALONG 81W/82W MENTIONED ABOVE IS ENHANCING SCATTERED SHOWERS AND TSTMS OVER CENTRAL AMERICA FROM WRN PANAMA TO HONDURAS AS WELL AS OVER THE NW CARIBBEAN WATERS FROM 18N-22N BETWEEN 84W-89W. CONVECTION IS ALSO LOCATED OVER NW VENEZUELA AND NRN COLOMBIA LIKELY DUE TO THE PRESENCE OF THE ITCZ AXIS. MODERATE TO STRONG EASTERLY TRADE WINDS CONTINUE ACROSS 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 NW CARIBBEAN ACROSS WRN CUBA TO OVER THE NW BAHAMAS AND THE W ATLC W OF 70W. AN UPPER-LEVEL LOW NEAR 30N59W 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 32N29W TO 22N45W. UPPER HIGH IS E OF THE WINDWARD ISLANDS NEAR 13N54W WITH THE RIDGE COVERING THE ERN CARIBBEAN TO THE WEST. ANOTHER UPPER-LEVEL HIGH CENTERED 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 1025 MB HIGH CENTERED NEAR 29N56W. 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 DURING THE NEXT 24 HOURS. $$ HUFFMAN