ZCZC MIATCDAT3 ALL TTAA00 KNHC DDHHMM Hurricane Gert Discussion Number 13 NWS National Hurricane Center Miami FL AL082017 1100 PM EDT Tue Aug 15 2017 Gert looked a bit ragged in satellite imagery earlier this evening, with the eye disappearing and microwave data showing the center to be in the northwest portion of the convective mass. Since then, the cloud pattern has become better organized, with a well-defined convective band now present around the center. Satellite intensity estimates from TAFB and SAB have increased to 77 kt, and thus the initial intensity is increased to 75 kt. Gert continues to recurve into the westerlies between the subtropical ridge and a baroclinic zone extending from North Carolina to Nova Scotia, and the initial motion is now 035/13. The hurricane should accelerate northeastward during the next 24-48 h, passing well south of the Canadian Maritimes and Atlantic Provinces. After that, the cyclone will then likely slow down and turn more northward by day 4 as it interacts with a large baroclinic low moving eastward from northeast Canada. The track guidance remains tightly clustered, and the new forecast track is little changed from the previous track. Conditions appear conducive for additional strengthening during the next 24 h as Gert remains over warm water and in a light/moderate vertical shear environment. The new intensity forecast raises the peak into to 85 kt, which is on the low side of the intensity guidance. After that time, Gert should move over cooler water and begin to merge with the above-mentioned baroclinic zone. The cyclone is now forecast to become extratropical in 48 h, to persist as an extratropical low through 96 h, and then be absorbed by the baroclinic low by 120 h. As mentioned in the previous advisory, the large-scale models suggest the possibility that Gert may survive as its own entity beyond 96 h, and a 120 h point could be added in later advisories. Swells from Gert should spread northward along the mid-Atlantic coast of the United States during the next few days, with the first impacts expected to occur tonight. These swells are likely to produce dangerous surf and rip current conditions. Please consult products from your local National Weather Service office. FORECAST POSITIONS AND MAX WINDS INIT 16/0300Z 34.8N 70.3W 75 KT 85 MPH 12H 16/1200Z 36.3N 67.6W 80 KT 90 MPH 24H 17/0000Z 38.5N 62.2W 85 KT 100 MPH 36H 17/1200Z 41.1N 54.8W 75 KT 85 MPH 48H 18/0000Z 44.9N 46.8W 65 KT 75 MPH...POST-TROP/EXTRATROP 72H 19/0000Z 53.0N 35.5W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 20/0000Z 55.5N 31.5W 45 KT 50 MPH...POST-TROP/EXTRATROP 120H 21/0000Z...ABSORBED BY EXTRATROPICAL LOW $$ Forecaster Beven NNNN