000 WTPZ44 KNHC 200243 TCDEP4 TROPICAL STORM CELIA DISCUSSION NUMBER 4...CORRECTED NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP042010 800 PM PDT SAT JUN 19 2010 CORRECT SAB INTENSITY ESTIMATE CELIA HAS CONTINUED TO GET BETTER ORGANIZED THIS EVENING...WITH THE OCCASIONAL GLIMPSE OF AN EYE TRYING TO FORM INSIDE A WELL-DEFINED CENTRAL DENSE OVERCAST. THE INITIAL INTENSITY IS A BIT UNCERTAIN. SATELLITE INTENSITY ESTIMATES ARE 45 KT FROM TAFB AND SAB...WHILE AMSU-BASED INTENSITY ESTIMATES ARE 65-70 KT. THE ATTEMPTS AT EYE FORMATION SUGGEST AN INTENSITY NEAR THE HIGHER END OF THESE ESTIMATES...ALTHOUGH THE EYE IS NOT YET PERSISTENT ENOUGH TO JUSTIFY CALLING CELIA A HURRICANE. THE INITIAL INTENSITY IS INCREASED TO 55 KT...AND THIS COULD BE CONSERVATIVE. THE INITIAL MOTION IS 255/7. ALL OF THE LARGE-SCALE MODELS MAINTAIN A MID-LEVEL RIDGE TO THE NORTH OF CELIA THROUGH 96 HR... AND THEN SUBSEQUENTLY ERODE THE WESTERN PERIPHERY OF THE RIDGE AS AN UPPER-LEVEL TROUGH DIGS SOUTHWARD OFF THE WEST COAST OF THE U.S. AND BAJA CALIFORNIA. THIS EVOLUTION SHOULD STEER THE CYCLONE WEST-SOUTHWESTWARD AND WESTWARD FOR 72-96 HR...WITH A WEST- NORTHWESTWARD MOTION AFTER THAT. THE TRACK GUIDANCE GENERALLY AGREES WITH THIS SCENARIO...ALTHOUGH THE GFS STILL APPEARS TO TAKE CELIA TOO FAR SOUTH DURING THE FIRST 48 HR. THE NEW FORECAST TRACK IS A LITTLE TO THE SOUTH OF THE PREVIOUS TRACK. IT LIES NORTH OF THE CENTER OF THE TRACK GUIDANCE ENVELOPE FOR THE FIRST 72 HR AND SOUTH OF THE CENTER OF THE ENVELOPE AFTER THAT TIME. CELIA IS CURRENTLY UNDERGOING RAPID INTENSIFICATION. HOWEVER... CIRRUS CLOUDS BLOWING INTO THE CDO FROM THE EAST SUGGEST VERTICAL WIND SHEAR IS OCCURRING...AND THAT MAKES IT UNCERTAIN HOW LONG THE CURRENT INTENSIFICATION WILL CONTINUE. WHILE THE GFS MODEL STILL FORECASTS CELIA TO BE AFFECTED BY SHEAR DURING THE 12-48 HR PERIOD...IT IS FORECASTING LESS SHEAR THAN 6 HR AGO. THE SHIPS MODEL RESPONDS TO THIS BY FORECASTING CELIA TO BECOME A MAJOR HURRICANE IN 96 HR. ON THE OTHER HAND...THE GFDL...HWRF...AND GFDN KEEP CELIA A TROPICAL STORM FOR MOST OF THE NEXT 5 DAYS...WITH ONLY THE GFDL FORECASTING IT TO BE A HURRICANE AT 120 HR. GIVEN THE UNCERTAINTY...THE NEW INTENSITY FORECAST FOLLOWS THE TRENDS OF THE PREVIOUS FORECAST BUT AT A HIGHER INTENSITY IN BEST OVERALL AGREEMENT WITH THE SHIPS MODEL. IF THE SHEAR TURNS OUT TO BE LESS THAN FORECAST...CELIA COULD GET SIGNIFICANTLY STRONGER THAN CURRENTLY FORECAST. FORECAST POSITIONS AND MAX WINDS INITIAL 20/0300Z 12.1N 98.7W 55 KT 12HR VT 20/1200Z 11.9N 99.8W 65 KT 24HR VT 21/0000Z 11.8N 101.0W 75 KT 36HR VT 21/1200Z 11.7N 102.2W 80 KT 48HR VT 22/0000Z 11.7N 103.2W 80 KT 72HR VT 23/0000Z 12.0N 105.5W 85 KT 96HR VT 24/0000Z 12.5N 108.5W 90 KT 120HR VT 25/0000Z 13.5N 112.0W 95 KT $$ FORECASTER BEVEN