000 AXNT20 KNHC 160600 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT WED JUL 16 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 36.8N 61.6W AT 16/0300 UTC OR ABOUT 310 NM NORTH-NORTHEAST OF BERMUDA. ESTIMATED MINIMUM CENTRAL PRESSURE IS 996 MB. MAXIMUM SUSTAINED WIND SPEED IS 55 KT WITH GUSTS TO 65 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 TROPICAL STORM STRENGTH AND APPEARS LIKELY TO BE HEADED FOR A SLOW DEMISE AS IT TRAVERSES OVER COOLER WATERS AND EXPERIENCES INCREASING SOUTHWESTERLY SHEAR OVER THE NEXT COUPLE OF DAYS. WIDELY SCATTERED MODERATE CONVECTION IS WITHIN 120 NM OF THE CENTER WITH A BROADER AREA OF SCATTERED MODERATE CONVECTION IN THE NORTHWEST QUADRANT FROM 37N-39N BETWEEN 61W-63W. STRONG TROPICAL WAVE IS ALONG 52W S OF 17N MOVING W NEAR 20 KT WITH A 1012 MB LOW ANALYZED ALONG THE AXIS NEAR 12N MOVING ROUGHLY WNW. THE SATELLITE PRESENTATION IS NOT AS WELL DEFINED AS YESTERDAY BUT MAIN CONVECTIVE ACTIVITY REMAINS ROUGHLY FOCUSED WITHIN 150 NM OF THE LOW CENTER. CLUSTERS OF SCATTERED MODERATE CONVECTION ARE FROM 10N-14N BETWEEN 50W-55W. THIS SYSTEM IS EXPECTED TO BRING GUSTY WINDS AND LOCALLY HEAVY RAINFALL TO THE WINDWARD ISLANDS OVER THE NEXT COUPLE OF DAYS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 33W S OF 17N MOVING W 15-20 KT. A MID LEVEL LOW IS EMBEDDED WITHIN THE ITCZ ALONG THE WAVE AXIS NEAR 9N WITH INVERTED-V CURVATURE OBSERVED ON SATELLITE IMAGERY. THIS WAVE EXHIBITS VERY LITTLE IN THE WAY OF DEEP CONVECTION WITH ONLY SCATTERED SHOWERS ASSOCIATED WITH THE ITCZ ALONG 8N BETWEEN 32W-35W. TROPICAL WAVE EXTENDS FROM THE WRN DOMINICAN REPUBLIC NEAR 19N71W TILTED ALONG 14N73W TO INLAND OVER NW VENEZUELA/NE COLOMBIA MOVING W 15-20 KT. THIS FEATURE REMAINS WELL DEFINED WITH AN INVERTED-V CURVATURE ON SATELLITE IMAGERY. SCATTERED MODERATE CONVECTION IS FROM 18N-21N BETWEEN 72W-74W ACROSS HAITI AND THE WINDWARD PASSAGE. SCATTERED MODERATE TO STRONG CONVECTION IS FARTHER SOUTH IN AN AREA FROM 7N-13N BETWEEN 68W-76W ACROSS NRN COLOMBIA. THE ITCZ... ITCZ AXIS IS CENTERED ALONG 8N13W 6N19W 9N26W 8N31W 8N36W 10N50W 10N55W ALONG THE N COAST OF SOUTH AMERICA ACROSS PANAMA INTO THE E PACIFIC REGION. SCATTERED MODERATE CONVECTION IS FROM 4N-6N BETWEEN 20W-24W AND FROM 1N-3N BETWEEN 39W-45W. SCATTERED MODERATE TO STRONG CONVECTION IS INLAND AND WITHIN 60 NM ALONG THE COAST OF SOUTH AMERICA AND PANAMA BETWEEN 71W-83W. ...DISCUSSION... GULF OF MEXICO... DEEP LAYERED TROUGH IS OVER THE E U.S. DIPPING S OVER THE N GULF PROVIDING SUPPORT FOR A STATIONARY FRONT THAT IS SAGGING S INTO THE N GULF FROM TALLAHASSEE FLORIDA JUST OFF SHORE OF ALABAMA AND MISSISSIPPI INTO SE LOUISIANA NEAR NEW ORLEANS. A WEAK 1013 MB LOW IS ANALYZED WEST OF TAMPA FLORIDA NEAR 27N83W AT 16/0300 UTC WITH A SURFACE TROUGH EXTENDING WSW TO NEAR 24N87W. THIS SURFACE LOW ALONG WITH DIFFLUENCE ALOFT OVER THE ERN GULF IS PRODUCING SCATTERED SHOWERS AND THUNDERSTORMS FROM 24N-29N E OF 85W AND ACROSS THE WRN COAST OF THE FLORIDA PENINSULA. ELSEWHERE AT THE SURFACE ACROSS THE GULF W OF 85W...IT REMAINS FAIRLY TRANQUIL WITH LIGHT WINDS AS A WEAK SURFACE RIDGE BUILDS BACK INTO THE WRN GULF BY LATE WED. AN UPPER LEVEL RIDGE EXTENDS E FROM TEXAS/NRN MEXICO COVERING THE GULF W TO 90W PRODUCING ONLY HIGH-MID LEVEL CLOUDINESS. THE SW GULF REMAINS RATHER CLEAR THIS EVENING UNDER A NE UPPER FLOW REGIME. CARIBBEAN SEA... AN UPPER TROUGH DOMINATES THE CENTRAL CARIBBEAN DRYING THE AIR NEAR ITS AXIS THAT EXTENDS FROM THE WINDWARD PASSAGE TO THE NICARAGUA/HONDURAS BORDER AND KEEPING THE AREA N OF 15N W OF 76W QUIET THIS EVENING. HOWEVER...UPPER DIFFLUENCE BETWEEN THIS TROUGH AND THE UPPER RIDGE OVER THE WRN GULF OF MEXICO IS PROVIDING AMPLE UPPER LEVEL MOISTURE ACROSS THE NW CARIBBEAN TO GENERATE MID-HIGH LEVEL CLOUDINESS. THE ITCZ IS ALONG THE N COAST OF SOUTH AMERICA AND PANAMA...SEE ABOVE. AN AREA OF SCATTERED MODERATE CONVECTION IS FROM 12N-14N BETWEEN 79W-83W IN ASSOCIATION WITH AN UPPER LEVEL DIFFLUENT PATTERN ACROSS THE SW CARIBBEAN. AN UPPER LEVEL HIGH DOMINATES THE ERN CARIBBEAN INTO THE W TROPICAL ATLC ANCHORED W OF THE WINDWARD ISLANDS NEAR 16N65W WHICH IS ENHANCING THE ACTIVITY ASSOCIATED WITH THE TROPICAL WAVE. ATLANTIC OCEAN... BROAD UPPER LEVEL TROUGH IS OVER THE E U.S. AND INTO THE FAR W ATLC WITH A NARROW UPPER RIDGE EXTENDING FROM SOUTH FLORIDA TO NEAR 31N74W PROVIDING AMPLE DIFFLUENCE TO GENERATE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WITHIN 60 NM OF A LINE FROM 32N73W TO 28N80W. AN AREA OF SURFACE HIGH PRESSURE IS LOCATED S OF T.S. BERTHA ANCHORED BY A 1022 MB HIGH NEAR 28N58W. A BROAD DEEP LAYERED TROUGH IS OVER THE CENTRAL ATLC N OF 15N BETWEEN 42W-55W WITH A SURFACE TROUGH ENTERING THE REGION NEAR 32N45W TO 28N47W GENERATING SCATTERED SHOWERS AND POSSIBLE ISOLATED THUNDERSTORMS WITHIN 120 NM EAST OF THE TROUGH. AN UPPER RIDGE EXTENDS FROM THE UPPER HIGH IN THE ERN CARIBBEAN TO OVER THE W ATLC W OF 56W. A LARGE UPPER LEVEL HIGH IS CENTERED OVER THE E ATLC ANCHORED W OF THE CANARY ISLANDS NEAR 30N25W COVERING THE AREA E OF 38W. A SURFACE RIDGE EXTENDS INTO THE E ATLC THROUGH 32N29W SW TO 19N40W. $$ HUFFMAN