000 AXNT20 KNHC 051803 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 PM EDT SAT JUL 05 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 16.6N 37.3W AT 1500 UTC OR ABOUT 770 NM W OF THE CAPE VERDE ISLANDS AND ABOUT 1480 NM E OF THE NORTHERN LEEWARD ISLANDS MOVING W AT 18 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT42 KNHC FOR MORE DETAILS. BERTHA WILL BE ABOUT HALF WAY BETWEEN THE WEST COAST OF AFRICA AND THE LESSER ANTILLES BY TONIGHT OR EARLY SUNDAY. BERTHA IS EXPECTED TO GRADUALLY STRENGTHEN AS UPPER LEVEL ATMOSPHERIC CONDITIONS APPEAR MORE FAVORABLE AND THE SYSTEM MOVES ACROSS INCREASING SEA SURFACE TEMPERATURES. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS LOCATED W OF THE CIRCULATION CENTER FROM 15N-20N BETWEEN 36W-40W...WITH ONLY ISOLATED MODERATE CONVECTION FOUND WITHIN 280 NM OF THE CENTER IN THE NE QUADRANT. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 62W S OF 23N MOVING W 20 KT. DESPITE THE HIGH AMPLIFICATION NOTED IN SATELLITE IMAGERY THERE IS MINIMAL ASSOCIATED CONVECTION. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS LIMITED TO THE NORTHERN EXTENT OF THE WAVE AXIS FROM 21N-22N BETWEEN 60W-63W. SURFACE OBSERVATIONS ACROSS THE NRN LESSER ANTILLES ALSO CONFIRMS POSITION OF THE WAVE. TROPICAL WAVE IS ALONG 76W S OF 21N MOVING W NEAR 15 KT. SATELLITE IMAGERY SHOWS SLIGHT LOW-LEVEL CURVATURE ALONG WAVE AXIS. THE WAVE IS MOVING INTO AN AREA OF BETTER UPPER LEVEL DIFFLUENCE WITH SCATTERED MODERATE CONVECTION FROM 17N-20N BETWEEN 72W-78W. TROPICAL WAVE IS OVER CENTRAL AMERICA ALONG 90W S OF 17N MOVING W NEAR 15 KT. THIS WAVE CONTINUES TO PROPAGATE WWD AND INTO THE OPEN WATERS OF THE E PACIFIC. PLEASE REFER TO THE EASTERN PACIFIC TROPICAL WEATHER DISCUSSION...TWDEP...FOR MORE INFORMATION. VERY LITTLE CONVECTIVE ACTIVITY IS ACROSS SRN MEXICO...GUATEMALA AND EL SALVADOR IN ASSOCIATION WITH THIS WAVE. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 11N14W 7N23W 9N28W 15N30W 10N38W 6N53W ALONG THE SOUTH AMERICA COAST TO 9N60W. SCATTERED MODERATE CONVECTION IS FROM 7N-13N BETWEEN 20W-26W. ...DISCUSSION... THE GULF OF MEXICO... THE LARGE SCALE PATTERN ACROSS THE GULF CONSISTS OF AN UPPER LEVEL LOW CENTERED ACROSS SRN FLORIDA WITH TROUGHING EXTENDING SOUTHWARD ACROSS WRN CUBA AND BROAD RIDGING EXTENDING FROM THE BAY OF CAMPECHE ACROSS THE WRN AND CENTRAL GULF WATERS. THIS RIDGING IS PROVIDING PREDOMINANTLY WESTERLY UPPER FLOW ACROSS THE ENTIRE REGION. WITH UPPER LEVEL ANTICYCLONIC CIRCULATION CENTER ACROSS THE SWRN GULF...THIS IS AIDING IN PRODUCING SCATTERED MODERATE TO STRONG TSTMS IN THE WRN GULF FROM 21N-26N W OF OF 94W INCLUDING COASTAL S TEXAS FROM CORPUS CHRISTI TO NEAR TUXPAN MEXICO. ELSEWHERE...THE REMAINDER OF THE GULF REMAINS FAIRLY TRANQUIL WITH ONLY A FEW SCATTERED SHOWERS/TSTMS IN THE NE GULF WITHIN 90 NM OFFSHORE OF PANAMA CITY FLORIDA. AT THE SURFACE...RIDGE OF HIGH PRESSURE EXTENDING FROM THE W ATLC COVERS MUCH OF THE NRN GULF KEEPING E-SE WINDS LIGHT N OF 23N AND E OF 90W. THE CARIBBEAN SEA... A PAIR OF TROPICAL WAVES ARE PROPAGATING ACROSS THE SEA. THE EASTERN ONE ALONG 62W IS WELL DEFINED ON SATELLITE IMAGERY AS SCATTERED SHOWERS WITH ISOLATED TSTMS ARE ACROSS THE UK/US VIRGIN ISLANDS AND ERN PUERTO RICO. FURTHER ENHANCEMENT OF THIS CONVECTIVE ACTIVITY IS EXPECTED DURING THE NEXT 24 HOURS AS WAVE MOVES UNDER A GRADUALLY STRENGTHENING UPPER LEVEL DIFFLUENT PATTERN. THE OTHER WAVE ALONG 76W IS AIDING IN PRODUCING SCATTERED SHOWERS AND TSTMS ACROSS THE OPEN WATERS OF THE CENTRAL GREATER ANTILLES INCLUDING THE WINDWARD PASSAGE. ELSEWHERE...SCATTERED SHOWERS/TSTMS ARE ACROSS THE SW CARIBBEAN FROM COASTAL PANAMA TO 12N W OF 80W IN ASSOCIATION WITH A WEAK 1010 MB LOW N OF WRN PANAMA AND CLOSE PROXIMITY TO THE E PACIFIC ITCZ. THE ATLANTIC OCEAN... THE UPPER PATTERN REMAINS DIFFLUENT OVER THE W ATLC IN ASSOCIATION WITH BROAD TROUGHING OVER THE ERN CONUS AND AN UPPER LOW CENTERED OVER SRN FLORIDA. SCATTERED SHOWERS AND TSTMS ARE E OF THE UPPER LOW N OF CUBA ACROSS SRN FLORIDA...THE ERN STRAITS OF FLORIDA AND THE NW BAHAMAS. E OF 75W A BROAD AMPLIFIED RIDGE COVERS THE REST OF THE W ATLC IN THE UPPER LEVELS. FARTHER E...A LARGE UPPER LOW IS SPINNING NORTH OF THE AREA NEAR 35N49W WITH TROUGHING EXTENDING S TO NEAR 22N58W. LARGE SCALE RIDGING HOLDS E OF THERE WITH AN UPPER HIGH POSITIONED NEAR 20N39W. OVERALL... THIS PATTERN IS PRODUCING LITTLE SENSIBLE WEATHER. AT THE SURFACE...A PAIR OF QUASI-STATIONARY HIGH CENTERS ARE OVER THE CENTRAL ATLC...ONE ANALYZED 1025 MB NEAR 33N60W...THE OTHER 1029 MB HIGH NEAR 38N39W. A SURFACE TROUGH IS WEAKENING THE RIDGE FROM 31N49W TO 26N57W. THIS TROUGH APPEARS TO BE PARTLY ASSOCIATED WITH THE LARGE TROPICAL WAVE TO THE SW AND THE UPPER LOW CENTERED TO THE NW. SCATTERED LOW-LEVEL SHOWERS ARE WITHIN 90 NM OF THE TROUGH AXIS. $$ HUFFMAN