000 AXNT20 KNHC 031804 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT THU JUL 03 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. ...SPECIAL FEATURE.... TROPICAL STORM BERTHA CENTERED NEAR 13.3N 24.7W AT 1500 UTC OR ABOUT 165 NM S/SW OF THE CAPE VERDE ISLANDS MOVING W/NW NEAR 12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1006 MB. MAXIMUM SUSTAINED WIND SPEED IS 35 KT WITH GUSTS TO 45 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT42 KNHC FOR MORE DETAILS. MORNING VISIBLE SATELLITE IMAGERY SHOWS CLOUD PATTERN SURROUNDING BERTHA HAS BECOME MORE ORGANIZED WITH SCATTERED MODERATE TO ISOLATED STRONG CONVECTION LOCATED WITHIN 120 NM OF THE CENTER. SOME GRADUAL STRENGTHENING IS FORECAST DURING THE NEXT FEW DAYS. OUTER RAINBANDS ASSOCIATED WITH BERTHA ARE EXPECTED TO BRING GUSTY WINDS AND LOCALLY HEAVY RAINFALL TO PORTIONS OF THE SOUTHERN CAPE VERDE ISLANDS DURING THE NEXT 24 HOURS. ...TROPICAL WAVES... TROPICAL WAVE IS TILTED ALONG 43W/44W S OF 18N MOVING W 10-15 KT. DESPITE THE HIGH AMPLIFICATION OF THIS FEATURE...THERE IS NOT MUCH ASSOCIATED CLOUDINESS. ANY PREVIOUSLY ASSOCIATED CONVECTION HAS DISSIPATED IN THE PAST FEW HOURS. ISOLATED SHOWERS ARE JUST WEST OF THE WAVE FROM 3N-8N BETWEEN 42W-44W. LOW AMPLITUDE TROPICAL WAVE IS ALONG 50W/51W S OF 12N MOVING W 10-15 KT. THE WAVE REMAINS WEAK WITH LITTLE SIGNATURE NOTED IN AVAILABLE DATA...BUT IT MAY BE ENHANCING A FEW CLUSTERS OF CONVECTION WITHIN THE ITCZ FROM 1N-4N BETWEEN 49W-52W. WELL DEFINED TROPICAL WAVE IS LOCATED W OF THE LESSER ANTILLES ALONG 63W/64W S OF 17N MOVING W 15-20 KT. SCATTERED MODERATE CONVECTION IS FROM 13N-17N BETWEEN 61W-66W. GUSTY WINDS ARE LIKELY IN THIS ACTIVITY. THIS SYSTEM IS BEING SHEARED BY UPPER SW WINDS AS IT MOVES INTO AN UPPER DIFFLUENT ENVIRONMENT NOT CONDUCIVE FOR ADDITIONAL DEVELOPMENT. WEAK TROPICAL WAVE IS IN THE CENTRAL CARIBBEAN ALONG 77W S OF 15N MOVING W 15 KT. POSITION IS HIGHLY BASED ON CONTINUITY AS LITTLE SIGNATURE OR CONVECTION APPEARS TO BE ASSOCIATED WITH THIS FEATURE. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 16N18W 8N27W 9N36W 4N47W 6N54W 9N61W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN 23W-29W AND WITHIN 60NM N AND 120 NM S OF THE AXIS BETWEEN 36W-40W. ...DISCUSSION... THE GULF OF MEXICO... WESTERLY MID TO UPPER LEVEL FLOW ON THE S SIDE OF AN ELONGATED TROUGH ALONG THE ERN CONUS LIES OVER THE GULF OF MEXICO. THIS PATTERN IS CONTINUING TO BRING A FAIR AMOUNT OF MOISTURE ACROSS THE ENTIRE REGION. WHILE THE ENTIRE AREA IS NOT EXPERIENCING RAINFALL...LIGHTNING DATA INDICATES SCATTERED SHOWERS AND TSTMS ARE ACROSS THE WRN GULF FROM 22N-29N W OF 91. ANOTHER AREA OF SCATTERED ACTIVITY IS OFF THE WRN COAST OF FLORIDA FROM 25N-28N E OF 87W. UPPER DIFFLUENCE WILL LIKELY CONTINUE TO ENHANCE THIS ACTIVITY THROUGH PEAK DAYTIME HEATING AND THE EARLY EVENING. AT THE SFC...RIDGE OF HIGH PRESSURE EXTENDS FROM THE W ATLC ACROSS CENTRAL FLORIDA TO NEAR VERACRUZ MEXICO. THIS RIDGE SHOULD STRENGTHEN SLIGHTLY AND HOLD THROUGH THE REMAINDER OF THE WEEK. THE CARIBBEAN SEA... THE MOST SIGNIFICANT WEATHER FEATURE IS THE TROPICAL WAVE ALONG 63W/64W WEST OF THE LESSER ANTILLES IN THE ERN CARIBBEAN. REFER TO THE SECTION ABOVE FOR DETAILS. OTHERWISE...CONVECTION IS MAINLY CONFINED TO A COUPLE OF AREAS. ONE OF THE MORE PROMINENT AREAS IS OVER CENTRAL AMERICA FROM ERN HONDURAS SEWD INTO THE SW CARIBBEAN. TROPICAL WAVE ALONG 77W COUPLED WITH STRONG UPPER LEVEL DIFFLUENCE IS CONTINUING TO PRODUCE WIDESPREAD SHOWERS AND SCATTERED TSTMS ACROSS MUCH OF THE SW CARIBBEAN AND AREAS ACROSS INLAND COSTA RICA/NICARAGUA. HEAVY RAINFALL HAS PERSISTED OVER THE LAST COUPLE OF DAYS WITH POTENTIAL FOR FLOODING AND MUDSLIDES. THIS ACTIVITY IS WITHIN 60 NM OF A LINE FROM CARTAGENA COLOMBIA TO PUERTO CABEZAS NICARAGUA. SIMILAR ACTIVITY IS FROM 13N-16N BETWEEN 68W-73W ASSOCIATED WITH UPPER DIFFLUENCE TO THE E OF A WEAKENING TROUGH OVER THE CENTRAL CARIBBEAN. ELSEWHERE...WATER VAPOR IMAGERY SHOWS A FAIR AMOUNT OF MOISTURE...ESPECIALLY ON THE N SIDE OF AN UPPER HIGH NEAR 13N81W...BUT MUCH OF THIS REMAINS IN THE FORM OF MID-HIGH LEVEL CLOUDINESS ACROSS THE NW CARIBBEAN SEA N OF 17N. THE ATLANTIC OCEAN... THE UPPER PATTERN REMAINS DIFFLUENT OVER THE W ATLC BETWEEN ELONGATED TROUGHING OVER THE ERN SEABOARD OF THE U.S. AND A NARROW RIDGE JUST E OF THE BAHAMAS WITH ITS AXIS ALONG 70W. THIS PATTERN IS PRODUCING ABUNDANT CLOUDINESS W OF 70W WITH ISOLATED SHOWERS/TSTMS ACROSS GRAND BAHAMA ISLAND AND FROM 28N-31N BETWEEN 73W-76W. FARTHER E...AN UPPER LOW IS SPINNING NEAR 33N54W WITH TROUGHING EXTENDING S TO NEAR PUERTO RICO. LARGE SCALE RIDGING HOLDS E OF THERE WITH AN UPPER HIGH POSITIONED NEAR 21N43W. OVERALL...THIS PATTERN IS PRODUCING LITTLE SENSIBLE WEATHER. AT THE SFC...A PAIR OF QUASI-STATIONARY HIGHS...ONE 1028 MB HIGH\ IS CENTERED NEAR 35N40W...THE OTHER A 1027 MB HIGH CENTERED NEAR 34N58W IS MAINTAINING FAIR WEATHER CONDITIONS ACROSS MUCH OF THE ERN AND CENTRAL ATLC. ONLY EXCEPTION IS A WEAK LOW-LEVEL TROUGH ALONG 47W N OF 22N (ASSOCIATED WITH AN UPPER LOW MENTIONED ABOVE) WHICH IS WEAKENING THE RIDGE SLIGHTLY AND PRODUCING LOW-LEVEL SHOWERS IN ITS VICINITY. $$ WALTON/HUFFMAN