000 WTNT41 KNHC 271506 TCDAT1 TROPICAL STORM KYLE DISCUSSION NUMBER 8 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL112008 1100 AM EDT SAT SEP 27 2008 SATELLITE IMAGERY SHOWS LITTLE CHANGE IN THE STRUCTURE OF KYLE DURING THE PAST SEVERAL HOURS...WITH THE LOW-LEVEL CENTER NEAR THE SOUTHERN EDGE OF THE CENTRAL CONVECTION. ANALYSES FROM CIMSS AT THE UNIVERSITY OF WISCONSIN INDICATE THAT KYLE CONTINUES TO BE AFFECTED BY ABOUT 20 KT OF WEST-SOUTHWESTERLY VERTICAL WIND SHEAR. THE INITIAL INTENSITY WILL BE HELD AT 60 KT...WHICH IS A LITTLE HIGHER THAN THE SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB. A NOAA HURRICANE HUNTER AIRCRAFT IS ABOUT TO REACH THE CENTER OF KYLE TO PROVIDE ADDITIONAL DATA ON THE INTENSITY. KYLE CONTINUES IT ZIG-ZAG PATH ACROSS THE WESTERN ATLANTIC...WITH THE NORTHWEST JOG SEEN EARLIER NOW BEING FOLLOWED BY ANOTHER NORTHWARD JOG. THE SMOOTHED 12-HR MOTION USED IN THE ADVISORY IS 345/13. KYLE REMAINS BETWEEN A DEEP-LAYER TROUGH OVER THE EASTERN UNITED STATES AND A DEEP-LAYER RIDGE OVER THE CENTRAL ATLANTIC. THIS PATTERN SHOULD STEER KYLE GENERALLY NORTHWARD FOR 12-24 HR OR SO...FOLLOWED BY A TURN TOWARD THE NORTH-NORTHEAST AS KYLE ENTERS THE WESTERLIES. THE TIMING OF THIS TURN WILL DETERMINE IF THE CENTER OF KYLE MAKES LANDFALL IN MAINE...OR WHETHER IT MAKES LANDFALL IN NEW BRUNSWICK OR NOVA SCOTIA. WHILE THE OVERALL GUIDANCE ENVELOPE HAS CHANGED LITTLE SINCE THE LAST ADVISORY...THE GFDL AND HWRF MODELS HAVE SHIFTED TO THE LEFT FROM THEIR PREVIOUS RUNS AND NOW CALL FOR A LANDFALL IN MAINE. THE NEW FORECAST TRACK IS ESSENTIALLY THE SAME AS THE PREVIOUS TRACK...CALLING FOR THE CENTER OF KYLE TO MAKE LANDFALL IN SOUTHERN NEW BRUNSWICK IN ABOUT 48 HR. THE TRACK LIES JUST LEFT OF THE CENTER OF THE GUIDANCE ENVELOPE...BUT TO THE RIGHT OF THE GFDL AND HWRF. KYLE IS BECOMING EMBEDDED IN STRONG...AND DIVERGENT...UPPER-LEVEL WINDS. THE STRENGTH OF THE WINDS SUGGESTS CONTINUED SHEAR...WHICH WOULD INHIBIT STRENGTHENING...WHILE THE UPPER-LEVEL DIVERGENCE WOULD ENCOURAGE STRENGTHENING. THE GFDL...HWRF...AND SHIPS MODELS ALL FORECAST KYLE TO BECOME A HURRICANE BEFORE IT REACHES THE COLD WATER NORTH OF THE GULF STREAM IN 24-36 HR...AND THE INTENSITY FORECAST FOLLOWS SUIT. AFTER KYLE REACHES THE COLDER WATER...IT SHOULD WEAKEN AND BEGIN EXTRATROPICAL TRANSITIONS. KYLE IS EXPECTED TO BECOME EXTRATROPICAL OVER EASTERN CANADA BY 72 HR AND BE ABSORBED BY A FRONTAL SYSTEM BY 96 HR. THE FORECAST TRACK...INTENSITY...AND WIND RADII REQUIRE WATCHES FOR PORTIONS OF THE COAST OF MAINE AT THIS TIME. FORECAST POSITIONS AND MAX WINDS INITIAL 27/1500Z 32.1N 69.6W 60 KT 12HR VT 28/0000Z 34.7N 69.8W 65 KT 24HR VT 28/1200Z 38.8N 68.9W 70 KT 36HR VT 29/0000Z 43.0N 67.5W 65 KT 48HR VT 29/1200Z 46.7N 66.0W 45 KT...INLAND 72HR VT 30/1200Z 51.0N 64.0W 35 KT...EXTRATROPICAL INLAND 96HR VT 01/1200Z...ABSORBED BY FRONTAL SYSTEM $$ FORECASTER BEVEN