|
Show Selection: |
| #5422 (Received by flhurricane at: 11:10 PM 16.Aug.2004) TCDAT4 HURRICANE DANIELLE DISCUSSION NUMBER 15 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 PM EDT MON AUG 16 2004 EARLIER THIS EVENING DANIELLE EXHIBITED A SMALL 10 NM WIDE EYE COMPLETELY SURROUNDED BY COOLING CLOUD TOPS. SINCE THEN...CLOUD TOP TEMPERATURES HAVE WARMED A BIT WITH THE STRONGEST CONVECTION NOW OVER THE WESTERN SEMICIRCLE OF THE HURRICANE. THE EYE IS NOW ALMOST COMPLETELY OBSCURED...WHICH MAY BE A SIGN THAT DANIELLE IS BEGINNING TO EXPERIENCE SOME SHEAR. SATELLITE INTENSITY ESTIMATES ARE CONSISTENT WITH THIS AS INDICATED BY SLIGHTLY LOWER T NUMBERS FROM TAFB...SAB...AND AFWA. THE INITIAL INTENSITY WILL BE HELD AT 90 KT FOR THE TIME BEING. THE INITIAL MOTION IS 330/15...AND A DECELERATING TURN TO THE NORTH IS EXPECTED AS DANIELLE ROUNDS THE WESTERN PERIPHERY OF A MID-LEVEL RIDGE. MOST OF THE GUIDANCE IS IN GOOD AGREEMENT THROUGH 48 HOURS. AFTER THAT...THERE IS CONSIDERABLE DIVERGENCE IN THE MODEL GUIDANCE. THE GFS SHEARS OFF DANIELLE...ADVECTING THE MID/UPPER LEVEL CIRCULATION TO THE NORTHEAST OF A WEAKENING LOW-LEVEL CIRCULATION. THE OFFICIAL FORECAST ASSUMES THAT A VERTICALLY COHERENT SYSTEM WILL PERSIST AND EVENTUALLY BE PICKED UP BY STRONGER SOUTHWESTERLY FLOW AT DAYS 4 AND 5...FAVORING A TRACK CLOSE TO THE MODEL CONSENSUS AND PREVIOUS OFFICIAL FORECAST. INTENSITY GUIDANCE DISAGREES ON THE RATE OF WEAKENING...WITH SHIPS BRINGING THE WINDS DOWN MUCH FASTER THAN THE GFDL. THE SHEAR IS FORECAST TO INCREASE ONLY MODESTLY OVER THE NEXT TWO DAYS...WHILE SEA SURFACE TEMPERATURES WILL REMAIN RELATIVELY CONSTANT OR EVEN INCREASE A LITTLE. AS A RESULT...THE OFFICIAL FORECAST CALLS FOR ONLY SLOW WEAKENING THROUGH 72 HOURS...AS INDICATED BY THE GFDL...FOLLOWED BY THE MORE RAPID DECAY SHOWN BY THE SHIPS GUIDANCE. FORECASTER BERG/FRANKLIN FORECAST POSITIONS AND MAX WINDS INITIAL 17/0300Z 21.0N 39.2W 90 KT 12HR VT 17/1200Z 22.8N 40.2W 85 KT 24HR VT 18/0000Z 25.1N 41.0W 80 KT 36HR VT 18/1200Z 27.5N 41.2W 75 KT 48HR VT 19/0000Z 29.5N 41.0W 70 KT 72HR VT 20/0000Z 33.0N 39.5W 65 KT 96HR VT 21/0000Z 35.5N 35.5W 55 KT 120HR VT 22/0000Z 38.5N 29.5W 40 KT |
