Official Discussion issued by the National Hurricane Center
IKE (AL092008) DATA RELEASED: 9/7/2008 9:00:00 PM UTC
Copy of official data HURRICANE IKE DISCUSSION NUMBER 27 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092008 500 PM EDT SUN SEP 07 2008 THE LATEST AIR FORCE RECONNAISSANCE MISSION INDICATES THAT IKE HAS WEAKENED A LITTLE. THE PLANE FOUND A PEAK SFMR OF 91 KT AND 107 KT AT FLIGHT LEVEL. AN EYEWALL DROPSONDE SUGGESTED SURFACE WINDS AROUND 100 KT BUT THE DROP MAY NOT HAVE SAMPLED THE HIGHEST WINDS. WHILE THESE OBSERVATIONS WOULD NORMALLY SUPPORT A SLIGHTLY LOWER INTENSITY...THE CENTRAL PRESSURE FELL TO 945 MB...AND THE INITIAL INTENSITY IS LOWERED ONLY TO 105 KT. A RECENT SERIES OF MICROWAVE PASSES AND REPORTS FROM THE RECONNAISSANCE AIRCRAFT CONFIRM THAT AN OUTER EYEWALL HAS FORMED...BUT IT IS DOUBTFUL THAT THE EYEWALL REPLACEMENT CYCLE WILL COMPLETE PRIOR TO IKE REACHING CUBA. ACCORDINGLY...SIGNIFICANT STRENGTHENING IS NOT EXPECTED DURING THE NEXT 12 HOURS. ONCE INLAND OVER CUBA...WEAKENING IS EXPECTED BUT THE AMOUNT OF WEAKENING WILL DEPEND LARGELY ON HOW LONG THE CENTER STAYS OVER LAND. THE LATEST OFFICIAL FORECAST KEEPS IKE INLAND FOR APPROXIMATELY 24-36 HOURS SO SIGNIFICANT WEAKENING IS SHOWN. HOWEVER...ONLY A SMALL DEVIATION TO THE NORTH OR THE SOUTH COULD RESULT IN THE CENTER OF IKE MOVING BACK OVER WATER SOONER. IKE IS FORECAST TO REACH THE SOUTHEASTERN GULF OF MEXICO IN ABOUT 2 DAYS WHERE THE WATERS ARE WARM AND THE SHEAR IS FORECAST TO BE LOW. IKE'S POTENTIAL FOR RESTRENGTHENING OVER THE GULF OF MEXICO WILL DEPEND ON ITS STRUCTURE ONCE IT EMERGES FROM CUBA. IKE HAS BEEN WOBBLING WESTWARD DURING THE LAST SEVERAL HOURS WITH AN INITIAL MOTION ESTIMATE OF 270/12. A TURN TOWARD THE WEST- NORTHWEST IS EXPECTED TONIGHT OR MONDAY AS THE SUBTROPICAL RIDGE TO ITS NORTH WEAKENS. IN 2-3 DAYS...A SHORTWAVE TROUGH IS FORECAST TO MOVE THROUGH THE EASTERN UNITED STATES CAUSING ADDITIONAL WEAKENING OF THE RIDGE AND A REDUCTION IN IKE'S FORWARD SPEED. MOST OF THE DYNAMICAL MODELS NOW SHOW THE TROUGH BYPASSING IKE TO THE NORTH WITH A SHORTWAVE RIDGE BUILDING IN ITS WAKE. THIS PATTERN WOULD RESULT IN A SLIGHT LEFT TURN TOWARD THE WEST-NORTHWEST AT DAYS 4 AND 5. TRACK MODELS CONTINUE TO TREND SOUTHWARD AND THE OFFICIAL FORECAST IS NUDGED A LITTLE TO THE LEFT. HOWEVER...ONE SHOULD NOT FOCUS TOO MUCH ON SMALL CHANGES IN THE TRACK...AND IT IS MUCH TOO EARLY TO ANTICIPATE WHICH AREAS ALONG THE GULF COAST COULD BE IMPACTED BY THIS SYSTEM. FORECAST POSITIONS AND MAX WINDS INITIAL 07/2100Z 21.1N 74.6W 105 KT 12HR VT 08/0600Z 21.2N 76.5W 100 KT...INLAND 24HR VT 08/1800Z 21.7N 78.8W 85 KT...INLAND 36HR VT 09/0600Z 22.4N 80.8W 70 KT...INLAND 48HR VT 09/1800Z 23.2N 82.6W 65 KT 72HR VT 10/1800Z 24.5N 85.5W 75 KT 96HR VT 11/1800Z 26.0N 88.0W 90 KT 120HR VT 12/1800Z 27.0N 91.0W 100 KT $$ FORECASTER RHOME/BEVEN |