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| #1194283 (Received by flhurricane at: 4:36 PM 17.Aug.2024) TCDAT5 Hurricane Ernesto Discussion Number 25 NWS National Hurricane Center Miami FL AL052024 500 PM AST Sat Aug 17 2024 Recent infrared and microwave imagery indicate show that Ernesto`s convective activity is a little thin, with the deepest convection located in a small band just north of the center. Subjective and objective satellite intensity estimates have decreased through the day, and combined with the earlier data from the Hurricane Hunter aircraft--which only measured 700-mb wind of 74 kt--it is estimated that Ernesto`s maximum sustained winds are near 65 kt. Ernesto has slowed down during the day while moving away from Bermuda, and the initial motion is north-northeastward (030 degrees) at 5 kt. This slow motion is likely to continue for the next 12 hours or so, before the flow increases ahead of an approaching trough and causes Ernesto to accelerate toward the north-northeast on Sunday. The cyclone is forecast to turn northeastward on Monday, and model guidance continues to show the center passing just to the southeast of Newfoundland late Monday or Monday night. After passing Newfoundland, Ernesto is expected to accelerate further toward the east-northeast over the north Atlantic. The track guidance is very tightly packed through 72 hours, and no significant changes were required from the previous NHC forecast. Despite Ernesto`s recent weakening, the hurricane will move over warm waters of 28 degrees Celsius and within a light-shear environment for the next 24 hours or so. The storm`s current broad structure may not allow for significant strengthening within this otherwise favorable environment, but many of the dynamical hurricane models, global models, and consensus aids suggest that Ernesto could re-intensity by 5-10 kt over the next day or so. This is reflected in the official intensity forecast. Weakening should begin by 48 hours due increasing shear and Ernesto moving over colder waters north of the Gulf Stream, and the cyclone is likely to become post-tropical by 60 hours while it is passing near southeastern Newfoundland. The GFS and ECMWF models indicate that dissipation should occur by day 4 when the circulation opens up into a trough over the north Atlantic. Key Messages: 1. Ernesto is moving slowly, and its impacts on Bermuda are not over. Strong winds, heavy rainfall, coastal flooding, and battering waves should continue through tonight. The heavy rains will likely result in considerable life-threatening flash flooding, especially in low-lying areas on the island. 2. 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 early next week. Beach goers should be aware that there is a significant risk of life-threatening surf and rip currents, and should stay out of the water if advised by lifeguards. Surf and rip currents are also possible on the Bahamas, Bermuda, and Atlantic Canada during the next few days. 3. Ernesto could bring wind, wave, and rain impacts to portions of southeastern Newfoundland late Monday and Monday night. FORECAST POSITIONS AND MAX WINDS INIT 17/2100Z 33.3N 64.0W 65 KT 75 MPH 12H 18/0600Z 34.3N 63.6W 65 KT 75 MPH 24H 18/1800Z 36.5N 62.6W 70 KT 80 MPH 36H 19/0600Z 39.5N 60.9W 70 KT 80 MPH 48H 19/1800Z 43.0N 57.2W 65 KT 75 MPH 60H 20/0600Z 46.4N 50.9W 55 KT 65 MPH...POST-TROP/EXTRATROP 72H 20/1800Z 48.9N 42.1W 45 KT 50 MPH...POST-TROP/EXTRATROP 96H 21/1800Z...DISSIPATED $$ Forecaster Berg |
