000 AXNT20 KNHC 061050 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 AM EDT SUN JUL 06 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 1015 UTC. ...SPECIAL FEATURE.... THE CENTER OF TROPICAL STORM BERTHA IS NEAR 17.3N 43.2W AT 06/0900 UTC MOVING WEST 19 KT. THIS POSITION ALSO IS ABOUT 2110 KM EAST OF THE NORTHERN LEEWARD ISLANDS. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 1000 MB. THE MAXIMUM SUSTAINED WIND SPEED IS 45 KT WITH GUSTS TO 55 KT. PLEASE READ THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT2/WTNT22 KNHC AND THE LATEST PUBLIC ADVISORY UNDER MIATCPAT2/WTNT32 FOR MORE DETAILS. SCATTERED STRONG SHOWERS AND THUNDERSTORMS FROM 17N TO 18N BETWEEN 43W AND 44W. POSSIBLE SHOWERS ELSEWHERE FROM 15N TO 21N BETWEEN 39W AND 47W. THE LONG-TERM FORECAST FOR BERTHA IS TO MOVE WEST-NORTHWEST DURING THE FORECAST PERIOD...AND POSSIBLY BECOME A HURRICANE AFTER THE NEXT THREE DAYS. SEA SURFACE TEMPERATURES WILL BE FAVORABLE FOR DEVELOPMENT. EVERYTHING WILL DEPEND ON THE WIND SHEAR. ...TROPICAL WAVES... AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 25W/26W SOUTH OF 20N MOVING WEST 15 KT. BROKEN TO OVERCAST MULTILAYERED CLOUDS AND POSSIBLE PRECIPITATION FROM 5N TO 12N BETWEEN 23W AND 28W. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 68W SOUTH OF 24N MOVING WEST 20 TO 25 KT. LOW CLOUDS ARE MOVING CYCLONICALLY AROUND THE WAVE NO DEEP CONVECTIVE PRECIPITATION. A CARIBBEAN SEA TROPICAL WAVE IS ALONG 83W SOUTH OF 25N MOVING WEST 15 KT. THIS WAVE STRETCHES FROM JUST WEST OF THE FLORIDA KEYS TO CUBA TO COSTA RICA. LINGERING SHOWERS ARE NEAR THE WAVE. A MIDDLE TO UPPER LEVEL TROUGH PASSES OVER CUBA TO 19N78W TO TO 11N77W. SOME OF THE PRECIPITATION MAY BE RELATED TO THE WAVE AND SOME OF THE PRECIPITATION MAY BE RELATED TO THE OTHER MIDDLE TO UPPER LEVEL FEATURES. A WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 95W SOUTH OF 20N MOVING WEST 15 TO 20 KT. THIS WAVE STRETCHES FROM THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO. EARLIER ISTHMUS OF TEHUANTEPEC PRECIPITATION HAS WEAKENED. WIDELY SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE SOUTH OF 22N BETWEEN THE YUCATAN PENINSULA AND THE MEXICO COAST. ...THE ITCZ... 12N16W 8N25W 17N36W 14N39W 6N50W 5N56W. STRONG SHOWERS AND THUNDERSTORMS IN ONE CELL WITHIN A 15 NM RADIUS OF 9N14.5W. ISOLATED MODERATE SHOWERS ARE ELSEWHERE FROM 5N TO 10N BETWEEN AFRICA AND 30W...AND FROM THE EQUATOR TO 12N BETWEEN 30W AND 53W. ...DISCUSSION... THE GULF OF MEXICO... A MIDDLE TO UPPER LEVEL CYCLONIC CIRCULATION CENTER IS IN NORTHERN MEXICO SPREADING CYCLONIC FLOW ACROSS MEXICO NORTH OF 23N. SHOWERS AND THUNDERSTORMS ARE FROM 19N TO 22N...AND FROM 20N TO 22N ALONG THE MEXICO EAST COAST. AN UPPER LEVEL RIDGE FROM THE UPPER TEXAS COAST/SOUTHWESTERN LOUISIANA BORDER INTO THE SOUTHWESTERN CORNER OF THE GULF OF MEXICO IS SENDING UPPER LEVEL ANTICYCLONIC FLOW ACROSS PRACTICALLY THE ENTIRE GULF OF MEXICO. THE FLOW DOES NOT BECOME CYCLONIC UNTIL REACHING 84W FROM WEST TO EAST. A MIDDLE TO UPPER LEVEL TROUGH PASSES THROUGH 30N80W TO A CYCLONIC CIRCULATION CENTER NEAR 28N80W JUST OFF THE FLORIDA EAST COAST...TO THE CUBA COAST ALONG 80W...INTO THE CARIBBEAN SEA NEAR 17N79W. POSSIBLE SHOWERS IN THE ATLANTIC OCEAN AND THE CARIBBEAN SEA NORTH OF 17N WEST OF 77W. WIDELY SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE FROM 20N TO 25N BETWEEN 67W AND 70W UNDER UPPER LEVEL ANTICYCLONIC FLOW AND POSSIBLY IN AN AREA OF ENOUGH UPPER LEVEL DIFFLUENT WIND FLOW IN ORDER TO HELP THE DEVELOPMENT OF CONVECTIVE PRECIPITATION. THE CARIBBEAN SEA... UPPER LEVEL ANTICYCLONIC FLOW FROM A FEW SOURCES COVERS THE WEST OF 70W. SOME ANTICYCLONIC FLOW COMES FROM A WESTERN GULF OF MEXICO RIDGE...SOME COMES FROM A SEPARATE SMALL UPPER LEVEL RIDGE IN THE SOUTHWESTERN CORNER OF THE AREA. AN INVERTED MIDDLE TO UPPER LEVEL RIDGE IS ALONG 69W IN DRY AIR/SUBSIDENCE. CONVECTIVE DEBRIS CLOUDS AND MOSTLY LINGERING SHOWERS ARE WEST OF 75W. THE ATLANTIC OCEAN... BROAD UPPER LEVEL ANTICYCLONIC WIND FLOW COVERS THE AREA NORTH OF 25N BETWEEN 60W AND 74W. MIDDLE LEVEL CYCLONIC FLOW IS CUTTING INTO THE NORTHEASTERN CORNER OF THE SECTION OF UPPER LEVEL ANTICYCLONIC FLOW. AN UPPER LEVEL TROUGH PASSES THROUGH 32N49W TO 27N55W TO 22N60W. NO DEEP CONVECTIVE PRECIPITATION ACCOMPANIES THIS TROUGH. A MIDDLE TO UPPER LEVEL TROUGH EXTENDS THROUGH 31N23W TO 26N34W. A SURFACE RIDGE EXTENDS FROM A 1026 MB HIGH PRESSURE CENTER NEAR 33N58W TO 28N77W TO THE FLORIDA EAST COAST NEAR 28N. $$ MT