ZCZC MIATCDAT5 ALL TTAA00 KNHC DDHHMM HURRICANE NICOLE DISCUSSION NUMBER 39 NWS NATIONAL HURRICANE CENTER MIAMI FL AL152016 500 PM AST THU OCT 13 2016 Satellite imagery indicates that Nicole is weakening as it moves away from Bermuda, most likely due to increasing southwesterly vertical shear. The eye has mostly disappeared since the last advisory, and there has been some warming of the cloud tops near the center. Subjective satellite intensity estimates from TAFB and SAB are 102 and 90 kt, respectively, while the latest CIMSS ADT estimate is 112 kt. The initial intensity is reduced to 95 kt based mainly on the subjective estimates and continuity from earlier aircraft data. As mentioned in the previous advisory, increasing southwesterly shear and slightly lower sea surface temperatures along the forecast track should cause a gradual decrease in intensity during the next 24 to 36 hours. After that time, baroclinic forcing forecast by the dynamical models should keep Nicole as an intense low pressure area over the north Atlantic through early next week. What structure the cyclone might have later in the forecast period is uncertain, with the GFS and UKMET suggesting that the tropical cyclone warm core could become secluded with no cold air reaching the center. Based on this, the forecast continues to call for a post-tropical cyclone and not a fully extratropical/frontal cyclone. The intensity forecast is mainly an update of the previous forecast, and the 3-5 day intensity forecast is in agreement with guidance provided by the NOAA Ocean Prediction Center. The initial motion is now 040/18. The hurricane will continue northeastward as it becomes embedded within southwesterly flow ahead of a mid-latitude trough. The dynamical guidance continues to forecast that the trough should bypass Nicole in a couple of days, which is expected to cause the cyclone to slow down and meander well southeast of Newfoundland late in the forecast period. The track guidance remains in remarkably good agreement, and the NHC is again near the multi-model consensus and the previous forecast. FORECAST POSITIONS AND MAX WINDS INIT 13/2100Z 33.6N 63.2W 95 KT 110 MPH 12H 14/0600Z 35.0N 60.7W 90 KT 105 MPH 24H 14/1800Z 36.4N 56.8W 80 KT 90 MPH 36H 15/0600Z 37.8N 53.0W 75 KT 85 MPH 48H 15/1800Z 38.8N 50.5W 75 KT 85 MPH...POST-TROPICAL 72H 16/1800Z 39.0N 48.5W 70 KT 80 MPH...POST-TROPICAL 96H 17/1800Z 39.6N 46.5W 65 KT 75 MPH...POST-TROPICAL 120H 18/1800Z 42.0N 41.5W 65 KT 75 MPH...POST-TROPICAL $$ Forecaster Beven NNNN