000 AXNT20 KNHC 272355 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 805 PM EDT SAT SEP 27 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 FEATURES... AT 27/2100 UTC...T.S. KYLE IS UPGRADED TO HURRICANE STRENGTH. THREE HOURS LATER...AT 28/0000 UTC THE CENTER OF KYLE IS NEAR 35.4N 69.7W OR ABOUT 350 NM SOUTH OF NANTUCKET MASSACHUSETTS AND ABOUT 535 NM SOUTH-SOUTHWEST OF YARMOUTH NOVA SCOTIA MOVING TOWARD THE N AT 21 KT. THE ESTIMATED MINIMUM CENTRAL PRESSURE IS 995 MB. THE MAXIMUM SUSTAINED WIND SPEEDS ARE 65 KT WITH HIGHER GUSTS. A LITTLE ADDITIONAL STRENGTHENING IS POSSIBLE DURING THE NEXT 24 HOURS. HOWEVER...WEAKENING IS EXPECTED TO BEGIN LATE SUNDAY OR MONDAY. PLEASE READ THE LATEST NHC PUBLIC ADVISORY UNDER AWIPS/WMO HEADERS MIATCPAT1/ WTNT31 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMAT1/WTNT21 KNHC FOR MORE DETAILS. THE OVERALL ORGANIZATION OF THE CYCLONE APPEARS TO HAVE CHANGED LITTLE DURING THE DAY...WITH THE CENTER REMAINING NEAR THE SOUTHERN EDGE OF THE CONVECTION. SATELLITE IMAGERY SHOWS AN AREA OF MODERATE TO ISOLATED STRONG CONVECTION WITHIN 235 NM N OF KYLE'S CENTER. A RAINBAND OF MODERATE CONVECTION IS NOTED WITHIN 220 NM SE SEMICIRCLE. INTERESTS IN NEW ENGLAND AND THE CANADIAN MARITIMES SHOULD MONITOR THE PROGRESS OF KYLE. ...TROPICAL WAVES... A TROPICAL WAVE IS ADDED TO THE 1800 UTC ANALYSIS/SURFACE MAP ALONG 18W SOUTH OF 17N BASED ON VIS SATELLITE IMAGERY AND SFC OBSERVATIONS. IN ADDITION...THE SSMI-DERIVED TPW INDICATES A NORTH-SOUTH MOISTURE MAXIMUM BETWEEN THE CAPE VERDE ISLANDS AND THE WEST COAST OF AFRICA WHERE AN 850 MB VORTICITY MAXIMUM IS ALSO SEEN. SCATTERED SHOWERS ARE MAINLY AHEAD OF THE WAVE AXIS. A TROPICAL WAVE IS ALONG 39W SOUTH OF 18N MOVING WNW NEAR 10 KT. THIS WAVE IS PRODUCING DISORGANIZED SHOWERS AND TSTMS WITH A CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION WITHIN 100 NM WEST OF THE WAVE AXIS FROM 15N-17N. UPPER-LEVEL WINDS ARE EXPECTED TO REMAIN UNFAVORABLE FOR DEVELOPMENT AS THE SYSTEM CONTINUES TO MOVE SLOWLY WEST-NORTHWESTWARD. A TROPICAL WAVE IS ALONG 49W/50W SOUTH OF 15N MOVING WEST 10-15 KT. SOME INVERTED-V SIGNATURE IS NOTED ON SATELLITE IMAGERY. A SWIRL OF LOW LEVEL CLOUDS IS AHEAD OF THE WAVE AXIS NEAR 12N53W. THE WAVE IS GENERATING SCATTERED MODERATE CONVECTION FROM 10N-14.5N BETWEEN 46W-53W. A TROPICAL WAVE IS OVER THE SW CARIBBEAN ALONG 79W/80W SOUTH OF 14N MOVING WEST 10-15 KT. A SMALL HINT OF CYCLONIC CIRCULATION IS OBSERVED ON SFC OBSERVATIONS WITH A SHIP REPORTING SW WINDS NEAR 10N79W. AN AREA OF MODERATE TO ISOLATED STRONG CONVECTION IS OVER THE SW CARIBBEAN S OF 13N BETWEEN 80W-83W. ...THE ITCZ... THE ITCZ AXIS IS CENTERED ALONG 11N15W 8N25W 13N38W 9N45W 10N62W. OUTSIDE FOR THE CONVECTION ASSOCIATED WITH THE TROPICAL WAVES...A LARGE CLUSTER OF MODERATE TO STRONG CONVECTION IS OVER SIERRA LEONE. SCATTERED MODERATE CONVECTION IS FROM 4N-7N BETWEEN 19W-28W. SIMILAR CONVECTION IS WITHIN 70 NM NE OF LINE FROM 5N30W TO 9N34W. ...DISCUSSION... THE GULF OF MEXICO... A MIDDLE/UPPER LEVEL TROUGH EXTENDS FROM THE SE CONUS TO THE WESTERN PART OF THE BAY OF CAMPECHE. DRY AIR/SUBSIDENCE IS SEEN BEHIND THE TROUGH AXIS WHILE A BAND OF CLOUDINESS WITH EMBEDDED SHOWERS IS NOTED AHEAD OF THE TROUGH AXIS COVERING THE EASTERN PORTION OF THE BAY OF CAMPECHE...THE YUCATAN PENINSULA...THE SE PORTION OF THE GULF INCLUDING THE FLORIDA KEYS AND SOUTH FLORIDA. THIS UPPER FEATURE SUPPORTS A SFC TROUGH THAT RUNS FROM THE YUCATAN PENINSULA ALL THE WAY NE TO N FLORIDA NEAR TO 29N82W. SFC DATA AND AN EARLIER ASCAT PASS CLEARLY SHOW THE WIND SHIFT ASSOCIATED WITH THIS SFC TROUGH. PRES GRADIENT BETWEEN RELATIVE LOW PRESSURE OVER THE YUCATAN PENINSULA AND CENTRAL AMERICA AND HIGH PRESSURE BUILDING OVER THE WESTERN GULF IS PRODUCING NLY WINDS OF 15-20 KT OVER THE SW PORTION OF THE GULF INCLUDING THE BAY OF CAMPECHE. WINDS ARE EXPECTED TO INCREASE OVER THE SOUTH-CENTRAL GULF AT LEAST SUN THROUGH MON AS A LOW PRES CENTER CURRENTLY IN THE VICINITY OF BELIZE MOVES NW ACROSS THE YUCATAN PENINSULA. THE CARIBBEAN SEA... WIDESPREAD CLOUDINESS AND SHOWERS CONTINUE NEAR A BROAD AREA OF LOW PRESSURE LOCATED IN THE VICINITY OF BELIZE NEAR 18N87.5W THIS EVENING. ALTHOUGH SURFACE PRESSURES ARE NOT CURRENTLY FALLING...SOME SLOW DEVELOPMENT IS POSSIBLE DURING THE NEXT DAY OR TWO AS THE SYSTEM DRIFTS NORTHWARD AWAY FROM YUCATAN. HEAVY RAINS AND LOCALIZED FLOODING ARE POSSIBLE OVER PORTIONS OF SOUTHERN MEXICO...THE YUCATAN PENINSULA...BELIZE AND GUATEMALA DURING THE NEXT COUPLE OF DAYS. CURRENTLY...CONVECTION HAS FLARED UP OVER NORTHERN CENTRAL AMERICA AND ALSO OVER PARTS OF CUBA. A DIFFLUENT PATTERN ALOFT BETWEEN THE AFOREMENTIONED MID/UPPER LEVEL TROUGH AND AN UPPER- LEVEL HIGH SITUATED OVER BELIZE IS HELPING TO INDUCE THIS ACTIVITY. UPPER NELY FLOW COVERS MOST OF THE BASIN. THESE WINDS ARE ADVECTING MID/UPPER LEVEL MOISTURE ACROSS THE EASTERN CARIBBEAN WHERE A FEW SHOWERS ARE NOTED. THE SAN JUAN DOPPLER RADAR DEPICTS SCATTERED SHOWERS OVER THE UK/US VIRGIN ISLANDS...PUERTO RICO AND THE CARIBBEAN WATERS ASSOCIATED WITH PATCHES OF LOW LEVEL MOISTURE IN THE TRADE WINDS. THIS SHOWER ACTIVITY IS ALSO REACHING THE MONA PASSAGE AND DOMINICAN REPUBLIC. THE ATLANTIC OCEAN... THE MAIN FEATURE OF INTEREST ACROSS THE ATLC IS KYLE...THE SIXTH HURRICANE SO FAR THIS TROPICAL SEASON. KYLE IS CROSSING WELL EAST OF THE COAST OF NORTH CAROLINA...AND WILL THREATEN EASTERN NEW ENGLAND AND THE CANADIAN MARITIMES. SEE SPECIAL FEATURES FOR DETAILS. SWLY FLOW AHEAD OF THE ABOVE MENTIONED UPPER-LEVEL TROUGH OVER THE GULF OF MEXICO IS TRANSPORTING ABUNDANT UPPER-LEVEL MOISTURE THROUGH SOUTH-CENTRAL FLORIDA INTO THE W ATLC. A BROAD UPPER-LEVEL LOW IS OVER THE CENTRAL ATLC NEAR 22N47W. THE CYCLONIC FLOW REACHES THE LESSER ANTILLES. THIS LOW IS PRODUCING STRONG SWLY FLOW OVER THE TROPICAL WAVES LOCATED NEAR 39W AND 49W/50W. FURTHER EAST...A BROAD UPPER-LEVEL RIDGE CENTERED OVER WEST AFRICA DOMINATES THE REMAINDER OF THE ATLC. THIS RIDGE IS ENHANCING CONVECTION SOUTH OF THE ITCZ AXIS. AT THE SFC...A COLD FRONT ENTERS THE AREA NEAR 31N33W THEN CONTINUES SW TO NEAR 24N41W. A SFC RIDGE ENTERS THE DISCUSSION AREA BETWEEN KYLE AND THIS COLD FRONT COVERING PART OF THE WEST AND CENTRAL ATLC. A WEAK 1011 SURFACE LOW IS NE OF THE MADEIRA ISLANDS. $$ GR