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| #1060895 (Received by flhurricane at: 11:09 AM 09.Sep.2021) TCDAT2 Hurricane Larry Discussion Number 36 NWS National Hurricane Center Miami FL AL122021 1100 AM AST Thu Sep 09 2021 Larry continues to feature a banding-type eye on satellite images, and the eye is clearly evident on the Bermuda radar. Satellite and radar data also show a moat-like area of low precipitation between the eyewall and a large band of convection farther removed from the center. This outer band is expected to affect Bermuda or the waters just east of the island over the next several hours. Observations from an Air Force Hurricane Hunter aircraft indicate that the central pressure has changed little since yesterday. Flight-level winds from the aircraft were as high as 95 kt, but the peak SFMR-observed surface winds were only 69 kt. This again indicates that in this case the strong winds aloft are not being transported to the surface as effectively as in a typical hurricane at lower latitudes. Blending these data results in an intensity estimate of 80 kt for this advisory. This is just a little higher than the latest subjective Dvorak estimates from TAFB and SAB. The hurricane is gradually turning to the right and the initial motion is 340/14 kt. Larry is currently moving around the western side of a deep-layer subtropical anticyclone over the central Atlantic, and is passing east of Bermuda. The flow on the east side of a strong mid-level trough moving from the northeastern United States to Atlantic Canada will cause Larry to turn toward the northeast and accelerate in 24 to 48 hours. Larry will move near or over southeastern Newfoundland in 36 to 48 hours, and then move over the far north Atlantic around the end of the forecast period. There is very little change to the NHC track forecast from the previous advisory, which remains close to the various consensus model solutions. Larry is likely remain over warm waters with low shear for another 24 hours or so. Thus the system will probably maintain much of its intensity into Friday. By Friday night and over the weekend, cooler SSTs and increasing shear should cause weakening. However, baroclinic forcing associated with the trough to the west of the hurricane could slow the weakening process. The official intensity forecast keeps Larry at hurricane-force through 48 hours even as it undergoes extratropical transition. In 3-4 days, the global models show Larry merging with another large extratropical cyclone over the north Atlantic. Key Messages: 1. Large swells generated by Larry will continue to affect the Leeward Islands, portions of the Greater Antilles, the Bahamas, Bermuda, and the east coast of the United States and Atlantic Canada through the end of the week. These swells will likely cause life-threatening surf and rip current conditions, and beachgoers and other interests along these coasts are urged to follow the guidance of lifeguards and local officials this week. 2. The center of Larry is forecast to pass east of Bermuda later today, and tropical storm conditions are expected there today, along with a risk of coastal flooding. 3. Larry is forecast to move near or over portions of southeastern Newfoundland Friday night or early Saturday morning as it undergoes transition to a hurricane-force post-tropical cyclone. Hurricane conditions are storm surge are possible in portions of southeastern Newfoundland where a hurricane watch is in effect. Interests there should monitor updates to the forecast. FORECAST POSITIONS AND MAX WINDS INIT 09/1500Z 32.0N 61.6W 80 KT 90 MPH 12H 10/0000Z 34.5N 62.2W 80 KT 90 MPH 24H 10/1200Z 39.0N 60.8W 80 KT 90 MPH 36H 11/0000Z 44.8N 56.1W 75 KT 85 MPH 48H 11/1200Z 51.3N 49.1W 65 KT 75 MPH...POST-TROP/EXTRATROP 60H 12/0000Z 57.0N 43.5W 60 KT 70 MPH...POST-TROP/EXTRATROP 72H 12/1200Z 61.0N 40.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 96H 13/1200Z...MERGED $$ Forecaster Pasch |