000 WTPZ45 KNHC 181457 TCDEP5 TROPICAL STORM KIKO DISCUSSION NUMBER 15 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP152007 800 AM PDT THU OCT 18 2007 SATELLITE IMAGERY THIS MORNING SHOWS THAT KIKO IS A LITTLE BETTER ORGANIZED THAN 24 HR AGO...WITH A LESS ELONGATED LOW-LEVEL CIRCULATION. EASTERLY VERTICAL WIND SHEAR HAS DECREASED OVER THE PAST 24 HR...WHICH HAS ALLOWED THE CENTER TO BECOME MORE INVOLVED WITH THE CONVECTION. HOWEVER...THE SYSTEM STILL APPEARS SOMEWHAT RAGGED...AND BASED ON THIS AND UNCHANGED SATELLITE INTENSITY ESTIMATES THE INITIAL INTENSITY REMAINS 35 KT. THE CENTER OF KIKO MOVED FASTER DURING THE NIGHT...AND THE INITIAL MOTION ESTIMATE IS 040/8. ALL GUIDANCE AGREES THAT THE FORWARD SPEED SHOULD SLOW DURING THE NEXT 24-48 HR AS PRESSURES RISE OVER NORTHERN MEXICO IN THE WAKE OF THE EASTWARD-MOVING DEEP-LAYER TROUGH OVER THE UNITED STATES...ACCOMPANIED BY THE CENTER TURNING TO THE NORTH AND NORTHWEST NEAR OR OVER THE PACIFIC COAST OF MEXICO. AFTER 48 HR...A SECOND DEEP-LAYER TROUGH DEVELOPS OVER THE CENTRAL AND WESTERN U.S. THE LARGE-SCALE MODELS CONTINUE TO DISAGREE ON THE EVOLUTION OF THIS TROUGH AND ITS EFFECTS ON KIKO. THE ECMWF AND NOGAPS FORECAST THE TROUGH TO AMPLIFY FARTHER TO THE WEST... WITH KIKO TURNING NORTHWARD INTO MAINLAND MEXICO. THE UKMET AND GFS FORECAST THE TROUGH TO AMPLIFY FARTHER TO THE EAST...WITH RIDGING BUILDING NORTH OF KIKO CAUSING A WESTWARD TRACK INTO THE OPEN PACIFIC. RIGHT NOW...IT CANNOT BE DETERMINED WHICH OF THESE EXTREMES WILL BE RIGHT...SO THE FORECAST TRACK WILL COMPROMISE BETWEEN THEM WITH A CONTINUED SLOW MOTION TOWARD THE NORTHWEST. UPPER-LEVEL WINDS HAVE BECOME MORE FAVORABLE FOR DEVELOPMENT...WITH THE LARGE-SCALE MODELS FORECASTING THEM TO REMAIN FAVORABLE FOR AT LEAST THE NEXT 48-72 HR. THIS SHOULD ALLOW STRENGTHENING...WITH THE MAIN NEGATIVE FACTOR BEING THE PROXIMITY TO LAND. THE NEW INTENSITY FORECAST CALLS FOR FASTER INTENSIFICATION THEN THE PREVIOUS FORECAST...WITH KIKO REACHING A 55 KT INTENSITY BEFORE THE CENTER BRUSHES THE COAST OF MEXICO IN ABOUT 72 HR. KIKO COULD BECOME A HURRICANE IF THE CENTER STAYS FARTHER OFFSHORE...AS INDICATED BY THE GFDL MODEL. THE CURRENT POSITION AND NEW FORECAST TRACK REQUIRE WARNINGS AND WATCHES FOR PORTIONS OF THE COAST OF MEXICO AT THIS TIME. FORECAST POSITIONS AND MAX WINDS INITIAL 18/1500Z 16.4N 103.4W 35 KT 12HR VT 19/0000Z 17.0N 103.2W 35 KT 24HR VT 19/1200Z 17.5N 103.2W 40 KT 36HR VT 20/0000Z 18.0N 103.5W 45 KT 48HR VT 20/1200Z 18.5N 104.2W 50 KT 72HR VT 21/1200Z 19.5N 105.0W 55 KT...INLAND 96HR VT 22/1200Z 20.5N 106.0W 55 KT...OVER WATER 120HR VT 23/1200Z 22.0N 107.5W 60 KT $$ FORECASTER BEVEN