000 AXNT20 KNHC 060622 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0545 UTC. ...SPECIAL FEATURE.... THE CENTER OF TROPICAL STORM BERTHA IS NEAR 17.0N 41.2W AT 06/0300 UTC MOVING WEST 18 KT. THIS POSITION ALSO IS ABOUT 1835 KM WEST OF THE CAPE VERDE ISLANDS/2325 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 WITHIN A 30 NM RADIUS OF 17N42W. POSSIBLE SHOWERS ELSEWHERE FROM 16N TO 20N BETWEEN 38W AND 45W. THE LONG-TERM FORECAST FOR BERTHA IS TO MOVE WEST-NORTHWEST DURING THE FORECAST PERIOD...AND POSSIBLY BECOME A HURRICANE AFTER THE NEXT TREE DAYS. ...TROPICAL WAVES... A NEW ATLANTIC OCEAN TROPICAL WAVE IS ALONG 23W/24W SOUTH OF 20N MOVING WEST 10 TO 15 KT. NEARBY ITCZ PRECIPITATION. AN ATLANTIC OCEAN TROPICAL WAVE IS ALONG 65W/66 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 81W SOUTH OF 25N MOVING WEST 15 KT. THIS WAVE STRETCHES FROM THE FLORIDA KEYS TO CUBA TO PANAMA. PRECIPITATION IS WEAKENING AS THE CLOUD TOP TEMPERATURES ARE BECOMING WARMER. A WESTERN CARIBBEAN SEA TROPICAL WAVE IS ALONG 93W/94W SOUTH OF 17N MOVING WEST 15 TO 20 KT. THIS WAVE STRETCHES FROM THE ISTHMUS OF TEHUANTEPEC INTO THE EASTERN PACIFIC OCEAN. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS ARE SOUTH OF 22N BETWEEN THE YUCATAN PENINSULA AND 93W/94W. STRONG SHOWERS AND THUNDERSTORMS ARE IN THE ISTHMUS OF TEHUANTEPEC. ...THE ITCZ... 12N16W 8N25W 17N36W 14N39W 6N50W 5N56W. SCATTERED MODERATE SHOWERS TO ISOLATED STRONG THUNDERSTORMS FROM 5N TO 10N BETWEEN THE AFRICA COAST AND 22W...AND FROM 1N TO 11N BETWEEN 34W AND 54W. ISOLATED MODERATE SHOWERS ARE ELSEWHERE FROM THE EQUATOR TO 12N BETWEEN 22W AND 32W. ...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 20N TO 23N AND ALONG THE MEXICO WEST COAST NORTH OF 23N. 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. 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 78W/79W 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 32N24W TO 26N36W. A SURFACE RIDGE EXTENDS FROM A 1026 MB HIGH PRESSURE CENTER NEAR 33N56W TO BERMUDA TO 29N72W TO THE FLORIDA EAST COAST NEAR 28N/29N. $$ MT