000 AXNT20 KNHC 151201 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1045 UTC. ...SPECIAL FEATURES... TROPICAL STORM BERTHA IS CENTERED NEAR 34.7N 63.2W AT 15/0900 UTC OR ABOUT 165 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 MAINTAINING STRONG TROPICAL STORM STRENGTH AND IS FORECAST TO GRADUALLY INTENSIFY SLIGHTLY 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 AS BERTHA TURNS EASTWARD AND MOVES FARTHER AWAY FROM BERMUDA. DANGEROUS RIP CURRENTS ARE ALSO OCCURRING ALONG THE U.S. EAST COAST FROM THE CAROLINAS THROUGH SOUTHERN NEW ENGLAND. THE DEEPEST CONVECTION IS WITHIN 120 NM OF THE CENTER OVER THE SOUTHERN AND EASTERN SEMICIRCLES WITH SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS COVERING A BROAD AREA FROM 33N-36N BETWEEN 61W-64W. STRONG TROPICAL WAVE IS ALONG 45W/46W S OF 18N MOVING W NEAR 10-15 KT WITH A 1009 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. SCATTERED MODERATE CONVECTION IS FROM 11N-14N BETWEEN 47W-50W. MAINLY SCATTERED SHOWERS ARE WITHIN 300 NM ON EITHER SIDE OF THE AXIS FROM 10N-16N. THIS SYSTEM COULD BECOME A TROPICAL DEPRESSION DURING THE NEXT DAY OR TWO. ...TROPICAL WAVES... TROPICAL WAVE EXTENDS FROM EASTERN PUERTO RICO ALONG 66W/67W TO NEAR PUERTO CABELLO VENEZUELA MOVING W 15 KT. THIS FEATURE REMAINS WELL DEFINED WITH IR SATELLITE IMAGERY SHOWING INVERTED-V CURVATURE ALONG THE AXIS IN THE ERN CARIBBEAN. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE S OF 16N TO INLAND OVER VENEZUELA BETWEEN 64W-72W INCLUDING THE ABC ISLANDS. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 14N17W 13N24W 5N34W 8N44W 11N48W 9N61W AND ACROSS THE SW CARIBBEAN. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 5N-7N BETWEEN 11W-13W. SIMILAR CONVECTION IS FROM 5N-10N BETWEEN 27W-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 WITH A WEAK 1011 MB LOW ALONG THE BOUNDARY NEAR TALLAHASSEE FLORIDA. THIS SURFACE LOW PRESSURE COUPLED WITH THE DIFFLUENCE AHEAD OF THE UPPER TROUGH IS GENERATING SCATTERED SHOWERS AND THUNDERSTORMS MAINLY OVER THE NE GULF FROM 26N-29N BETWEEN 82W-87W. SCATTERED SHOWERS AND ISOLATED TSTMS ARE ALSO WITHIN 90 NM OFFSHORE IN THE NW GULF E OF THE PORT ARTHUR LOUISIANA AREA. SCATTERED SHOWERS 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. A SURFACE RIDGE ENTERS THE CENTRAL AND WRN GULF FROM THE NW CARIBBEAN AND IS ANCHORED IN THE GULF BY A 1016 MB HIGH NEAR 24N90W. AN UPPER HIGH IS OVER WEST TEXAS WITH THE RIDGE AXIS EXTENDING SE OVER THE GULF OF MEXICO TO NEAR WRN CUBA. THIS UPPER LEVEL DIFFLUENT PATTERN IS ENHANCING THE TSTM ACTIVITY OVER THE NRN GULF AS WELL AS AIDING IN THE AFOREMENTIONED CLUSTERS OF SCATTERED SHOWERS/THUNDERSTORMS OVER THE ERN GULF E OF 87W. CARIBBEAN SEA... AN UPPER LOW IS IN THE NORTH CENTRAL CARIBBEAN COVERING THE AREA N OF 15N FROM 70W-82W. THIS 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 NRN COLOMBIA ACROSS PANAMA INTO THE E PACIFIC REGION GENERATING SCATTERED SHOWERS AND TSTMS ALONG COASTAL PANAMA AND COSTA RICA BETWEEN 78W-84W. THE ERN CARIBBEAN IS DOMINATED BY AN UPPER RIDGE ANCHORED OVER THE LEEWARD ISLANDS WHICH IS ENHANCING THE CONVECTIVE ACTIVITY ASSOCIATED WITH THE TROPICAL WAVE ALONG 66W/67W. 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. BROAD UPPER LEVEL TROUGHING IS ACROSS THE ERN U.S. SEABOARD AND THE FAR W ATLC WATERS. IT EXTENDS TO THE PREVIOUSLY MENTIONED UPPER LOW CENTERED OVER ERN CUBA AND THE WINDWARD PASSAGE. THIS UPPER TROUGHING IS PROVIDING AMPLE DIFFLUENCE TO GENERATE SCATTERED SHOWERS AND TSTMS WITHIN 90 NM OF A LINE FROM 30N75W ACROSS GRAND BAHAMA ISLAND TO NEAR KEY LARGO FLORIDA. A NARROW UPPER RIDGE EXTENDS ALONG 60W FROM NORTH OF THE DISCUSSION AREA SWD TO NEAR 24N60W. A BROAD DEEP LAYERED TROUGH IS OVER THE CENTRAL ATLC N OF 18N BETWEEN 35W-55W WITH A DISSIPATING ASSOCIATED COLD FRONT NORTH OF THE AREA AND SURFACE TROUGH ENTERING THE AREA NEAR 32N41W TO 28N46W. SCATTERED SHOWERS ARE WITHIN 60 NM OF THE TROUGH. A LARGE UPPER LEVEL HIGH IS CENTERED OVER THE SOUTH CENTRAL AND WEST TROPICAL ATLC NEAR 17N61W AND EXTENDS OVER THE ERN CARIBBEAN. A SECOND UPPER LEVEL HIGH IS WEST OF THE CANARY ISLANDS NEAR 28N22W COVERING THE ERN ATLC E OF 35W. A SURFACE RIDGE OF HIGH PRESSURE EXTENDS ACROSS THE ERN ATLC ANCHORED ON A 1034 MB HIGH CENTERED WELL N OF THE AZORES. $$ HUFFMAN