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| #878162 (Received by flhurricane at: 4:39 PM 15.Oct.2016) TCDAT5 HURRICANE NICOLE DISCUSSION NUMBER 47 NWS NATIONAL HURRICANE CENTER MIAMI FL AL152016 500 PM AST SAT OCT 15 2016 Nicole is currently showing a hybrid structure. On the larger scale, the system has the appearance of an extratropical low, with cold air advection occurring over the southern semicircle and a developing frontal cloud band east through south of the center. However, the system has secluded an area of warm air near the center where a tropical cyclone wind and temperature structure exists. The earlier scatterometer overpass showed the radius of maximum winds to be about 75 n mi, and the warm core is strong enough to produce hurricane-strength AMSU intensity estimates. Based on little change in the appearance of the cloud pattern since the last advisory, the intensity is held at 75 kt. The GFS and the ECMWF continue to forecast organized central convection for the next 36-48 hours, indicating that Nicole is likely to maintain tropical cyclone characteristics. After that time, the cyclone should move over sea surface temperatures of 16 deg C or less that should cause the central convection to dissipate. Based on this, the intensity forecast calls for Nicole to become post-tropical by 72 hours and then fully extratropical by 96 hours. The latest dynamical model guidance forecasts the cyclone to be absorbed by another extratropical low by 120 hours, and that is now reflected in the intensity forecast. The new forecast is otherwise an update of the previous forecast. The initial motion is now 075/10. A slow easterly motion is expected during the next 36 hours or so while the cyclone is in an area of weaker flow in the mid-latitude westerlies. After that time, a large mid-latitude trough moving into eastern Canada should steer Nicole north-northeastward with an increase in forward speed. The new forecast track is again similar to the previous track and lies near the various consensus models. Guidance from the NOAA Ocean Prediction Center was used for the forecast wind radii. Swells from Nicole will affect Bermuda and portions of the U.S. east coast and Atlantic Canada during the next couple of days. By early next week, wave models suggest that long-period swell from Nicole will radiate outward and affect much of the North Atlantic basin. FORECAST POSITIONS AND MAX WINDS INIT 15/2100Z 39.4N 49.4W 75 KT 85 MPH 12H 16/0600Z 39.5N 48.0W 75 KT 85 MPH 24H 16/1800Z 39.8N 46.7W 70 KT 80 MPH 36H 17/0600Z 40.6N 45.5W 65 KT 75 MPH 48H 17/1800Z 42.5N 43.7W 65 KT 75 MPH 72H 18/1800Z 50.0N 38.0W 60 KT 70 MPH...POST-TROPICAL 96H 19/1800Z 60.0N 34.5W 55 KT 65 MPH...POST-TROP/EXTRATROP 120H 20/1800Z...ABSORBED BY EXTRATROPICAL LOW $$ Forecaster Beven |
