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Hurricane JOAQUIN Forecast Discussion Number 26
2015-10-04 04:52:42| National Hurricane Center (Atlantic)
Issued at 1100 PM AST SAT OCT 03 2015 000 WTNT41 KNHC 040252 TCDAT1 HURRICANE JOAQUIN DISCUSSION NUMBER 26 NWS NATIONAL HURRICANE CENTER MIAMI FL AL112015 1100 PM AST SAT OCT 03 2015 While the cloud pattern has deteriorated a little this evening, reports from an Air Force Reserve Hurricane Hunter aircraft indicate that Joaquin is still a Category 4 hurricane. The aircraft reported 700-mb flight-level winds of 131 kt southeast of the center along with a central pressure near 944 mb. Surface wind estimates from the Stepped Frequency Microwave Radiometer were as high as 126 kt, but it is uncertain how reliable these are. Based mainly on the flight-level winds, the initial intensity is decreased to 115 kt. The aircraft also reports that the size of the 50 kt and 64 kt wind radii have expanded in the southeastern quadrant. Joaquin has moved a little to the right for the past several hours and the initial motion is now 050/17. Water vapor imagery shows a mid- to upper-level low near 34N 71W and a mid- to upper-level ridge east of 60W between 25N and 40N. Joaquin is expected to turn north-northeastward between these features during the next 12 hours, with this motion continuing through about 48 hours. After that time, the tropical cyclone is expected to recurve northeastward into the westerlies and accelerate. The forecast track, which has been shifted about 30 n mi eastward from the previous track, lies near the center of the tightly clustered track guidance models. The intensity guidance is in good agreement that Joaquin should weaken during the forecast period as it encounters episodes of moderate to strong vertical wind shear. However, it is likely to be a Category 2 hurricane in 24-36 hours at the time of closest approach to Bermuda. Extratropical transition should begin around 72 hours and be complete by 96 hours, with the winds decreasing below hurricane force during the transition. The new intensity forecast is an update of the previous forecast and lies near the upper edge of the intensity guidance. The combination of the shift in the forecast track and the expansion of the hurricane-force winds requires a hurricane warning for Bermuda at this time. FORECAST POSITIONS AND MAX WINDS INIT 04/0300Z 28.0N 68.9W 115 KT 130 MPH 12H 04/1200Z 29.9N 67.3W 105 KT 120 MPH 24H 05/0000Z 32.3N 66.2W 95 KT 110 MPH 36H 05/1200Z 34.3N 65.0W 85 KT 100 MPH 48H 06/0000Z 36.4N 62.7W 80 KT 90 MPH 72H 07/0000Z 41.0N 52.5W 70 KT 80 MPH 96H 08/0000Z 45.5N 36.5W 60 KT 70 MPH...POST-TROP/EXTRATROP 120H 09/0000Z 50.5N 22.0W 55 KT 65 MPH...POST-TROP/EXTRATROP $$ Forecaster Beven
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