000 WTPZ41 KNHC 170230 TCDEP1 HURRICANE COSME DISCUSSION NUMBER 11 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP062007 800 PM PDT MON JUL 16 2007 SATELLITE IMAGERY THIS EVENING INDICATES THAT THE EYE SEEN EARLIER HAS DISAPPEARED...WITH COSME NOW SHOWING A SLIGHTLY RAGGED CENTRAL DENSE OVERCAST WITH TOPS COLDER THAN -70C. SATELLITE INTENSITY ESTIMATES REMAIN 65 KT FROM TAFB AND SAB...AND THAT REMAINS THE INITIAL INTENSITY FOR THIS ADVISORY. MICROWAVES IMAGES DUE DURING THE NEXT SEVERAL HOURS SHOULD PROVIDE ADDITIONAL INFORMATION ON THE CONVECTIVE STRUCTURE UNDER THE CDO. IT SHOULD BE NOTED THAT WHILE THE CONVECTIVE MASS AND STRONG WIND FIELDS ASSOCIATED WITH COSME COVER A FAIRLY SMALL AREA...IT HAS A RATHER LARGE OVERALL CYCLONIC ENVELOPE ON THE ORDER OF 400 N MI ACROSS. THE INITIAL MOTION IS NOW 295/11. THERE IS LITTLE CHANGE TO THE FORECAST TRACK PHILOSOPHY FROM THE PREVIOUS PACKAGE. A LOW/ MID-LEVEL RIDGE NORTH AND NORTHWEST OF COSME SHOULD STEER THE CYCLONE WEST-NORTHWESTWARD TO WESTWARD WITH SOME INCREASE IN FORWARD SPEED DURING THE FORECAST PERIOD. THE TRACK GUIDANCE IS IN GOOD AGREEMENT WITH THIS SCENARIO...WITH THE GUIDANCE SPREAD BETWEEN THE MORE NORTHERLY NOGPAS THAT TRACKS A WEAKENING COSME THROUGH THE HAWAIIAN ISLANDS...AND THE SOUTHERLY GFS AND ECMWF THAT TRACK IT ABOUT 100-150 N MI SOUTH OF THE BIG ISLAND. THE FORECAST TRACK IS SHIFTED A LITTLE TO THE RIGHT OF THE PREVIOUS FORECAST FOR THE FIRST 72 HR BASED MAINLY ON THE INITIAL POSITION AND MOTION... AND IS SIMILAR TO THE PREVIOUS TRACK THEREAFTER. THE NEW TRACK IS DOWN THE MIDDLE OF THE GUIDANCE ENVELOPE IN GOOD AGREEMENT WITH THE CONSENSUS MODELS. THE HURRICANE IS CURRENTLY IN AN ENVIRONMENT OF LIGHT/MODERATE EASTERLY VERTICAL SHEAR. COSME WILL BE SPENDING THE NEXT 72 HR OVER GRADUALLY DECREASING SEA SURFACE TEMPERATURES. THUS...THE STORM SHOULD WEAKEN EVEN THOUGH THE UPPER-LEVEL WINDS ARE FORECAST TO REMAIN FAVORABLE. AFTER 72 HR...THE SSTS INCREASE ALONG THE FORECAST TRACK...BUT THE LARGE-SCALE MODELS FORECAST MODERATE WESTERLY SHEAR TO DEVELOP. GIVEN THESE MIXED SIGNALS... THE INTENSITY FORECAST WILL CONTINUE TO CALL FOR SLOW WEAKENING AS PER THE PREVIOUS FORECASTS. HOWEVER... COSME COULD BE STRONGER THAN FORECAST AFTER 72 HR IF IT GOES SOUTH OF THE CURRENT FORECAST TRACK THROUGH AN AREA OF FORECAST LIGHTER SHEAR. FORECAST POSITIONS AND MAX WINDS INITIAL 17/0300Z 15.1N 132.6W 65 KT 12HR VT 17/1200Z 15.5N 134.2W 65 KT 24HR VT 18/0000Z 15.9N 136.4W 60 KT 36HR VT 18/1200Z 16.3N 138.8W 55 KT 48HR VT 19/0000Z 16.7N 141.4W 50 KT 72HR VT 20/0000Z 18.0N 147.0W 45 KT 96HR VT 21/0000Z 18.5N 153.5W 40 KT 120HR VT 22/0000Z 19.0N 159.0W 35 KT $$ FORECASTER BEVEN