000 AXNT20 KNHC 150600 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT TUE JUL 15 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. ...SPECIAL FEATURES.... TROPICAL STORM BERTHA IS CENTERED NEAR 34.2N 63.6W AT 15/0600 UTC OR ABOUT 120 NM NORTH-NORTHEAST OF BERMUDA. THE MINIMUM CENTRAL PRESSURE IS 995 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 60 KT WITH GUSTS TO 75 KT. PLEASE SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC AND THE PUBLIC ADVISORY UNDER MIATCPAT2/WTNT32 KNHC FOR MORE DETAILS. BERTHA IS CONTINUING TO MAINTAIN STRONG TROPICAL STORM STRENGTH AND IS FORECAST TO GRADUALLY INTENSIFY TO A HURRICANE AGAIN DURING THE NEXT 24 HOURS. LARGE SWELLS AND HIGH SURF ARE AFFECTING BERMUDA AND ARE EXPECTED TO GRADUALLY DECREASE DURING THE NEXT COUPLE OF DAYS. DANGEROUS RIP CURRENTS ARE ALSO OCCURRING ALONG THE U.S. EAST COAST FROM THE CAROLINAS THROUGH SOUTHERN NEW ENGLAND. THE DEEPEST CONVECTION IS WITHIN 100 NM OF THE CENTER OVER THE SOUTHERN AND EASTERN SEMICIRCLES WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS COVERING A BROAD AREA FROM 31N-35N BETWEEN 62W-65W. STRONG TROPICAL WAVE IS ALONG 44W/45W S OF 18N MOVING W NEAR 10-15 KT WITH A 1010 MB LOW ANALYZED ALONG THE AXIS NEAR 12N MOVING ROUGHLY WNW NEAR 15 KT. SATELLITE IMAGERY SHOWS A LARGE WELL DEFINED ENVELOPE OF CYCLONIC ROTATION...FOCUSED NEAR THE LOW CENTER. ISOLATED MODERATE CONVECTION IS FROM 11N-14N BETWEEN 45W-48W. MAINLY SCATTERED SHOWERS ARE WITHIN 300 NM ON EITHER SIDE OF THE AXIS FROM 6N-16N. THIS SYSTEM COULD BECOME A TROPICAL DEPRESSION DURING THE NEXT DAY OR TWO. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM THE BRITISH VIRGIN ISLANDS AND SAINT CROIX ALONG 65W/66W TO NEAR CARACAS VENEZUELA MOVING W 15 KT. THIS FEATURE REMAINS WELL DEFINED WITH IR SATELLITE IMAGERY SHOWING INVERTED-V CURVATURE ALONG THE AXIS IN THE E CARIBBEAN. SCATTERED SHOWERS/ ISOLATED THUNDERSTORMS ARE S OF 16N TO INLAND OVER VENEZUELA BETWEEN 61W-65W INCLUDING THE ABC ISLANDS. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 12N15W 7N35W 8N42W 11N49W 9N60W 11N64W AND ACROSS THE SW CARIBBEAN. SCATTERED/NUMEROUS STRONG CONVECTION IS FROM 5N-10N BETWEEN 26W-35W. ...DISCUSSION... GULF OF MEXICO... DEEP LAYERED TROUGH IS OVER THE ERN U.S. DIPPING S TO THE N GULF COAST. A STATIONARY FRONTAL BOUNDARY AT THE SURFACE IS ANALYZED ALONG THE N GULF COAST WHICH IS GENERATING SCATTERED SHOWERS AND THUNDERSTORMS MAINLY OVER THE NE GULF AND THE NRN FLORIDA PENINSULA. SCATTERED SHOWERS EXTEND WWD ALONG 28N TO NEAR THE TEXAS AND LOUISIANA BORDER. SCATTERED SHOWERS AND THUNDERSTORMS ARE ALSO ACROSS THE SE GULF AND SRN FLORIDA MOVING W TO E ACROSS THE FLORIDA PENINSULA INTO THE W ATLC. STRONG SUBSIDENCE AND DRY STABLE AIR ARE NORTH OF THE STATIONARY BOUNDARY THAT EXTENDS ACROSS THE SE CONUS. THE SURFACE RIDGE OVER THE W ATLC CONTINUES TO WEAKEN WITH A 1015 MB HIGH OVER THE W GULF NEAR 27N93W. AN UPPER HIGH IS OVER SW TEXAS WITH THE RIDGE AXIS EXTENDING SE OVER THE GULF OF MEXICO TO NEAR THE FLORIDA KEYS. THIS UPPER LEVEL DIFFLUENT PATTERN IS ENHANCING THE THUNDERSTORM ACTIVITY OVER THE NRN GULF AS WELL AS AIDING IN THE AFOREMENTIONED CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS OVER THE ERN GULF E OF 90W. CARIBBEAN SEA... AN UPPER LOW IS IN THE NORTH CENTRAL CARIBBEAN COVERING THE AREA N OF 13N FROM 70W-83W AND COMBINED WITH THE UPPER RIDGE THAT COVERS THE GULF OF MEXICO IS PROVIDING ABUNDANT UPPER LEVEL MOISTURE ACROSS THE NW CARIBBEAN SEA. THE ITCZ CROSSES THE SW CARIBBEAN FROM COLOMBIA TO COSTA RICA INTO THE E PACIFIC REGION GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS S OF 10N. THE ERN CARIBBEAN IS DOMINATED BY AN UPPER RIDGE ANCHORED IN THE S/CENTRAL ATLC WHICH IS ENHANCING THE CONVECTIVE ACTIVITY ASSOCIATED WITH THE TROPICAL WAVE ALONG 65W/66W. THE CENTRAL CARIBBEAN REMAINS TRANQUIL ALTHOUGH THERE ARE SOME HIGH LEVEL CLOUDS TRANSVERSING THE AREA S OF 15N FROM W TO E BETWEEN 75W-82W. ATLANTIC OCEAN... TROPICAL STORM BERTHA CONTINUES TO INFLUENCE THE AREA N OF THE REGION NEAR BERMUDA...SEE ABOVE. A MID/UPPER LOW IS MOVING NE OUT OF THE REGION ALONG THE ERN U.S. COAST WITH THE UPPER TROUGH EXTENDING THROUGH 32N75W TO THE CENTRAL BAHAMAS. A NARROW UPPER RIDGE EXTENDS ALONG 60W FROM NORTH OF THE DISCUSSION AREA SWD TO NEAR 23N60W. CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS ARE WITHIN 120 NM OF LINE FROM 32N74W TO GRAND BAHAMA ISLAND WITH MAINLY SCATTERED SHOWERS EXTENDING FARTHER SW ACROSS THE STRAITS OF FLORIDA. A BROAD DEEP LAYERED TROUGH IS OVER THE CENTRAL ATLC N OF 20N BETWEEN 35W-55W WITH A DISSIPATING ASSOCIATED COLD FRONT ALONG THE N PERIPHERY OF THE REGION FROM 41W-49W. SCATTERED SHOWERS WITH EMBEDDED ISOLATED TSTMS ARE WITHIN 60 NM OF A LINE FROM 32N42W TO 30N46W. A LARGE UPPER LEVEL HIGH IS CENTERED OVER THE SOUTH CENTRAL AND WEST TROPICAL ATLC NEAR 17N60W AND EXTENDS OVER THE ERN CARIBBEAN. A SECOND UPPER LEVEL HIGH IS SW OF THE CANARY ISLANDS NEAR 26N19W COVERING THE E ATLC E OF 35W. A SURFACE RIDGE OF HIGH PRESSURE EXTENDS ACROSS THE ERN ATLC ANCHORED ON A 1034 MB HIGH CENTERED N OF THE AZORES. $$ HUFFMAN