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#878089 (Received by flhurricane at: 11:03 PM 14.Oct.2016) TCDAT5 TROPICAL STORM NICOLE DISCUSSION NUMBER 44 NWS NATIONAL HURRICANE CENTER MIAMI FL AL152016 1100 PM AST FRI OCT 14 2016 Deep convection redeveloped northeast of Nicole`s center just after 1800 UTC and has persisted since that time despite nearly 50 kt of southwesterly shear. The Dvorak Current Intensity number from TAFB has decreased to 3.5, and Nicole`s initial intensity is therefore lowered conservatively to 60 kt. The future classification of Nicole continues to be a quandary, only because the system will be straddling the nebulous boundary of what constitutes a tropical and non-tropical cyclone. Nicole continues to have a warm core and has not become attached to a frontal boundary, and phase-space diagrams based off the global models indicate that the cyclone will only become more symmetric and develop a deeper warm core from this point forward. Nicole will likely become a warm seclusion, with its warm core isolated from surrounding colder air, and that structure could allow the cyclone to maintain tropical characteristics even at such a high latitude. Simulated infrared satellite imagery from the GFS and ECMWF models suggests that the cyclone may even develop an eye-like feature in a day or two. Given these model trends, it has become more likely that Nicole will retain tropical or subtropical characteristics, and the NHC forecast now does not show the system becoming post-tropical until day 4. This forecast remains highly uncertain, however, and does not eliminate the possibility of Nicole becoming post-tropical during the next day or so. Regardless of its classification, Nicole is expected to restrengthen during the next 12-24 hours, mostly due to forcing from an approaching mid-latitude trough. If more symmetric deep convection does develop, then the cyclone should be able to maintain hurricane intensity at least through day 3. The NHC intensity forecast closely follows the GFS and ECMWF models. The initial motion has increased to 065/19 kt. However, Nicole is expected to slow down considerably between 24-48 hours when it interacts with the approaching shortwave trough and becomes cut off from the mid-latitude westerlies. Another mid-latitude trough that will move across Atlantic Canada on day 3 should cause Nicole to accelerate north-northeastward on days 4 and 5. The track guidance is in very good agreement through the forecast period, and no significant changes were required from the previous NHC track forecast. The radii on the western side of Nicole`s circulation have been increased based on a recent ASCAT-B pass. 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 15/0300Z 37.4N 53.3W 60 KT 70 MPH 12H 15/1200Z 38.2N 51.0W 70 KT 80 MPH 24H 16/0000Z 38.6N 48.8W 70 KT 80 MPH 36H 16/1200Z 38.7N 47.5W 65 KT 75 MPH 48H 17/0000Z 39.0N 46.6W 65 KT 75 MPH 72H 18/0000Z 42.1N 43.3W 65 KT 75 MPH 96H 19/0000Z 50.5N 38.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 120H 20/0000Z 58.0N 34.0W 50 KT 60 MPH...POST-TROP/EXTRATROP $$ Forecaster Berg |