000 AXNT20 KNHC 010548 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN OCT 01 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR... AND METEOROLOGICAL ANALYSIS. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0515 UTC. ...SPECIAL FEATURES... HURRICANE ISAAC IS CENTERED NEAR 32.5N 59.9W AT 01/0300 UTC MOVING NORTH-NORTHWEST AT 9 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 989 MB. MAXIMUM SUSTAINED WIND SPEED IS 70 KT WITH GUSTS TO 85 KT. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT4/WTNT24 KNHC FOR MORE DETAILS. A BAND OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WEST OF THE CENTER FROM 31N-37N BETWEEN 62W-64W. THE HURRICANE WILL BEGIN TO INTERACT WITH A LARGE MID-LATITUDE TROUGH MOVING OFF THE EAST COAST OF THE UNITED STATES AND WILL BECOME EXTRATROPICAL IN ABOUT 36 HOURS. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 37W/38W S OF 21N MOVING W 15 KT. THE WAVE HAS A WEAK INVERTED-V SIGNATURE AND IS EMBEDDED WITHIN DRY AIR...THUS ONLY ISOLATED SHOWERS ARE NOTED. TROPICAL WAVE IS ALONG 63W S OF 18N MOVING W 15 KT. WAVE IS MOVING ACROSS THE EASTERN CARIBBEAN ENHANCING THE DEVELOPMENT OF MODERATE TO STRONG CONVECTION OVER VENEZUELA. THE WAVE WILL PASS MAINLY SOUTH OF THE VIRGIN ISLANDS AND PUERTO RICO TODAY. TROPICAL WAVE IS ALONG 73W MOVING W AT 10-15 KT. WEAK WAVE INVERTED-V SIGNATURE WITH SHOWERS AND THUNDERSTORMS FIRING UP OVER HISPANIOLA AND COLOMBIA IN RESPONSE TO THE PASSING OF THE WAVE AXIS. THIS WAVE IS ALSO GENERATING A CLUSTER OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION NEAR LAKE MARACAIBO VENEZUELA. TROPICAL WAVE IS ALONG 95W/96W OVER S MEXICO AND THE E PACIFIC REGION WITH SCATTERED SHOWERS EXTENDING OVER THE BAY OF CAMPECHE S OF 20N WEST OF 94W. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 11N14W 6N25W 7N36W 11N45W 9N60W. SCATTERED MODERATE CONVECTION ARE FROM 2N-10N EAST OF 34W. ISOLATED SHOWERS ARE ELSEWHERE. ...DISCUSSION... GULF OF MEXICO... DEEP LAYERED TROUGH COVERS THE E HALF OF THE US INTO THE GULF N OF 26N WITH THE LEADING EDGE OF THE UPPER TROUGH AND ASSOCIATED FRONTAL BOUNDARY IN THE W ATLC. A SHORTWAVE TROUGH AND SECOND FRONTAL SYSTEM ARE MOVING THROUGH THE UPPER MISSISSIPPI VALLEY. BROAD UPPER RIDGE ANCHORED OVER CENTRAL AMERICA AND IN THE E PACIFIC REGION COVERS THE REMAINDER OF THE S GULF. DRY AIR RESULTING IN MODERATE TO STRONG SUBSIDENCE DOMINATES THE MAJORITY OF THE GULF AND THE STATE OF FLORIDA WHILE ABUNDANT UPPER LEVEL MOISTURE IS SEEN OVER MEXICO AHEAD OF A SHORT WAVE TROUGH. AS OF 0300 UTC A 1020 MB HIGH IS OVER THE FLORIDA/GEORGIA BORDER WITH A RIDGE COVERING THE GULF. THIS IS GIVING THE ENTIRE AREA FAIR CONDITIONS TONIGHT. HIGH PRESSURE WILL BUILD OVER THE SOUTHEAST U.S. MONDAY AND TUESDAY WITH INCREASING EASTERLY WINDS ACROSS THE GULF. CARIBBEAN SEA... BROAD UPPER RIDGE ANCHORED OVER CENTRAL AMERICA AND IN THE E PACIFIC REGION COVERS THE W CARIBBEAN W OF 73W WITH AN EXTENSION OF THE RIDGE EXTENDING ACROSS E CUBA AND THE BAHAMAS INTO THE W ATLC. A SURFACE TROUGH IS PRODUCING HEAVY SHOWERS/SCATTERED THUNDERSTORMS OVER EASTERN CUBA AND CENTRAL BAHAMAS. A 1009 MB LOW IS IN THE SW CARIBBEAN NEAR 10N80W. AN UPPER LOW IN THE CARIBBEAN IS S OF THE MONA PASSAGE NEAR 16N68W COVERING THE REMAINDER OF THE CARIBBEAN. AN UPPER TROUGH EXTENDS FROM THE LOW TO THE ABC ISLANDS INTO VENEZUELA. SCATTERED SHOWERS/ISOLATED THUNDERSTORMS ARE OVER THE E CARIBBEAN E OF 67W ASSOCIATED WITH THE TROPICAL WAVE AND THE UPPER LOW/TROUGH OVER THE AREA. MODERATE TRADE WINDS ARE BLOWING OVER THE BASIN. ATLANTIC OCEAN... DEEP LAYERED TROUGH OVER THE E US EXTENDS INTO THE W ATLC W OF 73W. THE ASSOCIATED FRONTAL SYSTEM ENTERS THE AREA NEAR 32N68W THEN CONTINUES SW TO THE NORTHERN BAHAMAS. A SURFACE PRE-FRONTAL TROUGH EXTENDS FROM 26N74W ACROSS THE BAHAMAS TO OVER EASTERN CUBA...GENERATING SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 20N-25N BETWEEN 72W-78W. SIMILAR CONVECTION IS FOUND BEHIND THE FRONTAL BOUNDARY NORTH OF 27N. ANOTHER SURFACE TROUGH RUNS FROM 27N63W TO 20N69W. A DIFFLUENT PATTERN ALOFT IS ENHANCING THE SHOWER/TSTM ACTIVITY ASSOCIATED WITH THIS TROUGH. A CUT-OFF UPPER LOW IS IN THE CENTRAL ATLC NEAR 20N46W DRIFTING WESTWARD. BROAD UPPER RIDGE COVERS THE E ATLC E OF 30W WITH A 1019 MB HIGH CENTERED W OF THE CANARY ISLANDS NEAR 29N20W. A COLD FRONT IS APPROACHING THE E-CENTRAL ATLC FROM THE NORTH. WIDELY SCATTERED MODERATE CONVECTION IS AHEAD OF THE FRONT FROM 27N-31N BETWEEN 20W-34W. $$ GR