Official Discussion issued by the National Hurricane Center
IKE (AL092008) DATA RELEASED: 9/2/2008 3:00:00 AM UTC
Copy of official data TROPICAL STORM IKE DISCUSSION NUMBER 3 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL092008 1100 PM EDT MON SEP 01 2008 MICROWAVE AND CONVENTIONAL SATELLITE IMAGERY INDICATE THAT DEEP CONVECTION IS BEGINNING TO DEVELOP OVER THE WESTERN PORTION OF THE CYCLONE. HOWEVER...THE BANDING FEATURE OVER THE EAST SEMICIRCLE HAS ERODED A BIT...PARTICULARLY OVER THE NORTHEAST QUADRANT. REGARDLESS...DVORAK SATELLITE INTENSITY ESTIMATES REMAIN AT 45 KT AS WELL AS THE INITIAL INTENSITY. THE INTENSITY MODELS GENERALLY AGREE ON A CLIMATOLOGICAL STRENGTHENING RATE WITH TIME...AND SUGGEST THAT IKE WILL BECOME A HURRICANE IN 24 TO 36 HOURS. THERE IS HOWEVER A LITTLE DIVERGENCE IN WHAT THE MODELS ARE INDICATING BEYOND 48 HOURS. BOTH THE GFDL AND THE HWRF INTENSIFY IKE INTO A POWERFUL HURRICANE WHILE THE SHIPS AND LGEM INDICATE WEAKENING DUE TO INCREASING NORTHEASTERLY SHEAR. THE OFFICIAL INTENSITY FORECAST IS A COMPROMISE OF THE TWO SOLUTIONS AND IS VERY CLOSE TO THE ICON INTENSITY CONSENSUS. THE INITIAL INTENSITY IS ESTIMATED AT 275/12...WITHIN IN THE DEEP LAYER EASTERLY FLOW OF THE SUBTROPICAL RIDGE TO THE NORTH. THE DYNAMICAL MODELS ARE TIGHTLY CLUSTERED THROUGH THE 72 HOUR PERIOD. THROUGH THE REMAINDER OF THE FORECAST...THE UKMET IS THE ONLY GLOBAL MODEL OUTSIDE OF THE GUIDANCE CLUSTER AND INDICATES A MORE NORTHWESTWARD MOTION THROUGH DAY 5...WHILE THE OTHER GUIDANCE CONTINUES ON A WESTWARD MOTION. THE UKMET TRACK IS MORE THAN LIKELY DUE TO A DIFFERENCE IN THE POSITION OF A MID-LEVEL HIGH PRESSURE CENTER AND A WEAKNESS OVER THE SOUTHEAST U.S. CREATED BY A SLOWER MOVING HURRICANE HANNA. ACCORDINGLY...THE NHC FORECAST IS WEIGHED MORE HEAVILY ON A BLEND OF THE MODELS THAT SUGGEST A WESTWARD MOTION THROUGH THE LATTER PORTION OF THE FORECAST PERIOD. FORECAST POSITIONS AND MAX WINDS INITIAL 02/0300Z 18.0N 41.6W 45 KT 12HR VT 02/1200Z 18.5N 43.8W 55 KT 24HR VT 03/0000Z 19.2N 46.7W 60 KT 36HR VT 03/1200Z 20.0N 49.6W 70 KT 48HR VT 04/0000Z 20.8N 52.7W 75 KT 72HR VT 05/0000Z 22.0N 59.0W 80 KT 96HR VT 06/0000Z 22.0N 65.0W 85 KT 120HR VT 07/0000Z 22.0N 71.0W 90 KT $$ FORECASTER ROBERTS/FRANKLIN |