000 AXNT20 KNHC 060013 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2315 UTC. ...SPECIAL FEATURE.... TROPICAL STORM BERTHA IS CENTERED NEAR 16.7 NORTH...LONGITUDE 39.3 WEST OR ABOUT 1015 MILES...1635 KM...WEST OF THE CAPE VERDE ISLANDS AND ABOUT 1570 MILES...2530 KM...EAST OF THE NORTHERN LEEWARD ISLANDS. IT IS 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 WIND VELOCITY IS HOLDING STEADY WHILE TRAVERSING OVER AN AREA WITH COOLER SEA SURFACE TEMPERATURES. SATELLITE IMAGERY NOW SHOWS A LARGER AREA OF UPPER LEVEL OUTFLOW OVER THE STORM THAN YESTERDAY. BERTHA IS ALSO MAINTAINING CONVECTION NW OF THE CENTER WITH SCATTERED MODERATE TO ISOLATED STRONG CONVECTION FROM 16N-19N BETWEEN 39W-42W. ...TROPICAL WAVES... A NEW TROPICAL WAVE IS INTRODUCED ALONG 21W S OF 15N MOVING W AT 10-15 KT. AN INVERTED-V SIGNATURE IS NOTED ON SATELLITE IMAGERY S OF 15N IN THE VICINITY OF THE CAPE VERDE ISLANDS. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM OF 12N26W. SCATTERED SHOWERS ARE FROM 5N-16N BETWEEN 20W-30W. TROPICAL WAVE IS OVER THE E CARIBBEAN ALONG 64W S OF 23N MOVING W 20 KT. DESPITE THE HIGH AMPLIFICATION NOTED IN SATELLITE IMAGERY THERE IS MINIMAL ASSOCIATED CONVECTION. SCATTERED SHOWERS ARE HOWEVER OVER THE LEEWARD ISLANDS N OF 15N WITH ANOTHER BAND OF SHOWERS APPROACHING FROM THE W. TROPICAL WAVE IS ALONG 79W S OF 24N MOVING W NEAR 15 KT. SATELLITE IMAGERY SHOWS SLIGHT LOW-LEVEL CURVATURE ALONG WAVE AXIS. THE WAVE IS IS ENHANCING SCATTERED MODERATE TO STRONG CONVECTION OVER INLAND CUBA BETWEEN 75W-84W. SCATTERED MODERATE CONVECTION IS FURTHER N OVER THE N BAHAMAS FROM 22N-26N BETWEEN 77W-80W. SIMILAR CONVECTION IS ALSO OVER JAMAICA. TROPICAL WAVE IS OVER CENTRAL AMERICA ALONG 92W 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. SCATTERED MODERATE CONVECTION IS INLAND OVER SRN MEXICO... GUATEMALA AND EL SALVADOR FROM 12N-18N BETWEEN 88W-96W. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 11N15W 9N20W 9N28W 16N32W 11N40W 5N53W ALONG THE SOUTH AMERICA COAST TO 7N60W. SCATTERED MODERATE CONVECTION IS FROM 7N-9N BETWEEN 10W-20W. ISOLATED MODERATE CONVECTION IS FROM 4N-11N BETWEEN 22W-35W. ...DISCUSSION... THE GULF OF MEXICO... WEAK SURFACE RIDGING COVERS THE GULF OF MEXICO. 10-15 KT SELY SURFACE FLOW IS NOTED. CLUSTERS OF AIRMASS THUNDERSTORMS ARE OVER THE W GULF OF MEXICO AND S FLORIDA. ISOLATED MODERATE CONVECTION IS OVER THE S FLORIDA FROM 25N-27N BETWEEN 80W-82W. SCATTERED MODERATE CONVECTION IS OVER THE W GULF FROM 21N-28N BETWEEN 93W-99W MOSTLY DUE TO A SURFACE TROUGH IN THE VICINITY OF TAMPICO MEXICO FROM 25N98W TO 20N97W. IN THE UPPER LEVELS... A SMALL UPPER LEVEL LOW IS CENTERED OVER S FLORIDA NEAR 27N81W ENHANCING THE CONVECTION OVER FLORIDA AND THE BAHAMAS. THE ERN EXTENT OF AN UPPER LEVEL HIGH IS OVER THE W GULF OF MEXICO PRODUCING MAINLY NLY FLOW W OF 87W. CONSIDERABLE UPPER LEVEL MOISTURE COVERS THE ENTIRE GULF. EXPECT CONTINUED AIRMASS CONVECTION OVER MOST OF THE GULF DURING THE NEXT 24 HOURS. THE CARIBBEAN SEA... THREE TROPICAL WAVES ARE OVER THE CARIBBEAN AND CENTRAL AMERICA WITH CONVECTION. SEE ABOVE. MODERATE TO FRESH TRADEWINDS DOMINATE THE AREA. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS ALSO INLAND OVER CENTRAL AMERICA FROM PANAMA TO GUATEMALA...AND OVER THE SW CARIBBEAN...W OF 80W. IN THE UPPER LEVELS...AN UPPER RIDGE IS OVER THE W CARIBBEAN W OF 70W. SIGNIFICANT UPPER LEVEL MOISTURE COVERS THE CARIBBEAN W OF 70W. EXPECT THE TROPICAL WAVES TO MOVE W WITH CONVECTION DURING THE NEXT 24 HOURS. THE ATLANTIC OCEAN... CLUSTERS OF WIDELY SCATTERED MODERATE CONVECTION IS OVER THE W ATLANTIC NEAR FLORIDA FROM 26N-29N BETWEEN 76W-78W. A 1026 MB HIGH IS STATIONARY OVER THE W ATLANTIC NEAR 33N59W. ANOTHER 1030 MB HIGH IS OVER THE CENTRAL ATLANTIC NEAR 37N40W. A SURFACE TROUGH IS OVER THE CENTRAL ATLANTIC FROM 32N50W TO 27N58W. SCATTERED SHOWERS ARE WITHIN 90 NM OF THE TROUGH. IN THE UPPER LEVELS...AN UPPER LEVEL LOW IS CENTERED OVER THE CENTRAL ATLANTIC NEAR 27N53W. A RIDGE IS N OF 20N BETWEEN 38W-48W. ANOTHER UPPER LEVEL LOW IS OVER THE E ATLANTIC NEAR 30N28W. A LARGE UPPER LEVEL HIGH IS CENTERED OVER THE CAPE VERDE ISLANDS NEAR 16N27W. $$ FORMOSA