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| #1194053 (Received by flhurricane at: 4:48 AM 16.Aug.2024) TCDAT5 Hurricane Ernesto Discussion Number 19 NWS National Hurricane Center Miami FL AL052024 500 AM AST Fri Aug 16 2024 Ernesto`s strengthening trend has seemingly halted overnight. The cloud pattern near the center has become less organized, and the system appears to be struggling with dry air again with some eyewall erosion in the western semicircle. Still, the convective banding in the eastern side where the previous aircraft mission found the peak winds remains deep and well-defined, suggesting that Ernesto hasn`t lost much strength. The initial wind speed is kept at 85 kt for this advisory, a bit above the latest satellite estimates, pending the upcoming Air Force Reserve Hurricane Hunter aircraft mission this morning. The environment near Ernesto could support some strengthening today. However, the most noticeable change in the overnight intensity guidance aids is that almost all of them are showing more shear today than previously expected. This shear, combined with the environmental dry air, has led to this cycle`s intensity forecast values being a lot lower than 6 h ago. Given current trends, the NHC prediction has been decreased from the last forecast, and is still on the high side of the guidance. It is worth noting that despite the peak wind speed reductions, the forecast size is generally larger than the previous forecast, so the life-threatening hazards from Ernesto are unchanged. After the hurricane passes Bermuda, there could be a brief window for some re-intensification in lighter shear conditions plus favorable trough influences before Ernesto crosses into cool waters, and little change was made at longer range. Ernesto continues moving north-northeastward at about 11 kt, steered by the flow between a ridge over the central Atlantic and a large-scale trough off the U.S. east coast. This general motion is expected to persist for the next day or two, bringing the hurricane near or over Bermuda on Saturday. The trough is forecast is lift out over the weekend, causing Ernesto to slow down and turn a bit to the north or north-northeast. Another trough is expected to approach the cyclone late in the weekend, and that feature should cause Ernesto to accelerate to the northeast near or east of Newfoundland early next week. The NHC track forecast continues to the trend of the previous one, nudged a touch to the east and a little slower through its passage near Bermuda to come into better agreement with the latest aids. Key Messages: 1. Ernesto is expected to bring a prolonged period of strong winds and storm surge on Bermuda starting this afternoon through Saturday night. A hurricane warning is in effect for the island, and preparations to protect life and property should be rushed to completion. 2. Heavy rainfall associated with Ernesto is expected to impact Bermuda through this weekend and will likely result in considerable life-threatening flash flooding. 3. Even though Ernesto is forecast to remain well offshore the U.S. East Coast, swells generated by the hurricane are expected to affect the area through the weekend. Beach goers should be aware of a significant risk of life-threatening surf and rip currents, and stay out of the water if advised by lifeguards. Surf and rip currents are also possible on the Turks and Caicos, the Bahamas, Bermuda, and Atlantic Canada during the next few days. FORECAST POSITIONS AND MAX WINDS INIT 16/0900Z 28.1N 67.0W 85 KT 100 MPH 12H 16/1800Z 29.6N 66.2W 90 KT 105 MPH 24H 17/0600Z 31.5N 65.2W 85 KT 100 MPH 36H 17/1800Z 32.8N 64.8W 80 KT 90 MPH 48H 18/0600Z 34.2N 64.4W 75 KT 85 MPH 60H 18/1800Z 36.2N 63.6W 75 KT 85 MPH 72H 19/0600Z 39.4N 61.6W 80 KT 90 MPH 96H 20/0600Z 47.0N 51.0W 60 KT 70 MPH...POST-TROPICAL 120H 21/0600Z 52.5N 31.0W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ Forecaster Blake |
