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| #828053 (Received by flhurricane at: 9:50 PM 14.Jan.2016) TCDAT1 HURRICANE ALEX DISCUSSION NUMBER 6 NWS NATIONAL HURRICANE CENTER MIAMI FL AL012016 1100 PM AST THU JAN 14 2016 Satellite imagery indicates that the convective structure of Alex has decayed during the past 6 hours, with the eyewall breaking open and the banding dissipating in the southeastern semicircle. Based on this, the initial intensity is lowered to 70 kt. The hurricane is moving over colder sea surface temperatures of less than 20C. However, the cyclone should begin extratropical transition in the next few hours, and the global models suggest there will be enough baroclinic forcing to maintain hurricane-force winds through and after the transition despite the cold water. Based on this and input from the Ocean Prediction Center, the new intensity forecast shows little change in strength until Alex is absorbed by a large extratropical low in about 72 hours. The initial motion is 010/19. There are no changes to the forecast philosophy from the previous advisory and only minor tweaks to the forecast track. Alex continues to be steered by the flow of a shortwave mid-tropospheric trough that is rotating around the developing large baroclinic low to its west and northwest. This evolution should cause the cyclone to turn gradually to the left with increasing forward speed over the next couple of days. The dynamical track guidance models remain in excellent agreement for the first 36 hours of the forecast, and the official forecast is near the model consensus. Alex's wind field is likely to expand as it undergoes extratropical transition. The wind radii forecasts are based primarily on guidance from the NOAA Ocean Prediction Center. FORECAST POSITIONS AND MAX WINDS INIT 15/0300Z 34.7N 27.6W 70 KT 80 MPH 12H 15/1200Z 38.4N 27.8W 65 KT 75 MPH 24H 16/0000Z 45.0N 29.1W 65 KT 75 MPH...POST-TROP/EXTRATROP 36H 16/1200Z 52.7N 32.1W 65 KT 75 MPH...POST-TROP/EXTRATROP 48H 17/0000Z 59.0N 37.0W 65 KT 75 MPH...POST-TROP/EXTRATROP 72H 18/0000Z...ABSORBED BY EXTRATROPICAL LOW $$ Forecaster Beven |
