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| #1060935 (Received by flhurricane at: 5:03 PM 09.Sep.2021) TCDAT2 Hurricane Larry Discussion Number 37 NWS National Hurricane Center Miami FL AL122021 500 PM AST Thu Sep 09 2021 A faint eye is still discernible on visible satellite images along with some banding features. On the Bermuda radar, the eyewall is partially open over the southern semicircle of the hurricane. Larry still has a prominent upper-tropospheric outflow pattern, especially over the northern portion of the circulation. The advisory intensity is held at 80 kt, just above the latest Dvorak Current Intensity Numbers from TAFB and SAB. Larry is now heading a little west of north at an increasing forward speed, and the initial motion is 345/17 kt. The hurricane has been moving around the western side of a large deep-layer high pressure area centered over the central Atlantic. By Friday, the system should accelerate northeastward ahead of a strong mid-tropospheric trough over the northeastern United States, and pass near or over southeastern Newfoundland within 36 hours. Thereafter, post-tropical cyclone Larry should move over the far North Atlantic. The official track forecast again lies close to the various consensus model predictions. The hurricane is expected to remain over warm waters with weak vertical shear for another 12 to 24 hours. Thereafter, Larry is forecast to move over the cooler waters north of the Gulf Stream and the shear will increase. These factors should induce weakening, but possible baroclinic forcing associated with the trough to the west of the cyclone could result in Larry maintaining some strength over the next few days. The NHC intensity forecast is similar to the latest NOAA corrected-consensus guidance, HCCA. Global model predictions indicate that Larry will merge with a front, and therefore become an extratropical cyclone, in 48 hours. These models also show the system merging with another large extratropical low over the north Atlantic in 3 to 4 days. Key Messages: 1. 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 and dangerous storm surge are expected in portions of southeastern Newfoundland where a Hurricane Warning in effect. 2. 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 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. 3. Tropical storm conditions are expected on Bermuda through this evening, along with a risk of coastal flooding. FORECAST POSITIONS AND MAX WINDS INIT 09/2100Z 33.9N 62.2W 80 KT 90 MPH 12H 10/0600Z 36.8N 61.8W 80 KT 90 MPH 24H 10/1800Z 42.2N 59.0W 75 KT 85 MPH 36H 11/0600Z 48.4N 52.9W 70 KT 80 MPH 48H 11/1800Z 55.0N 46.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 60H 12/0600Z 59.5N 42.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 72H 12/1800Z 61.5N 40.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 96H 13/1800Z...MERGED $$ Forecaster Pasch |