000 WTNT44 KNHC 180256 TCDAT4 Hurricane Humberto Discussion Number 22 NWS National Hurricane Center Miami FL AL092019 1100 PM EDT Tue Sep 17 2019 Humberto has an impressive presentation on satellite images, with a large 30-40 n mi diameter eye surrounded by very cold cloud tops. An Air Force Reserve Unit Hurricane Hunter aircraft investigating the hurricane found SFMR-observed surface winds of 98 kt and peak 700-mb flight-level winds of 111 kt. Based on these observations, the current intensity was set at 100 kt, which made the system a major hurricane. Some fluctuations in strength due to a potential eyewall replacement are possible during the next 24 hours or so, but strong southwesterly shear should result in a weakening trend to commence on Thursday. In 72 hours, the global models show the system merging with a frontal zone so the NHC forecast calls for extratropical transition by that time. The official intensity forecast follows the model consensus. Center fixes from the Hurricane Hunters indicate that the motion continues to be east-northeastward or 075/10 kt. Humberto is likely to turn toward the northeast and north-northeast at a faster forward speed in 24-36 hours as it interacts with a strong mid-level trough at mid-latitudes to its north and northeast. Later in the forecast period, the track guidance indicates that Humberto will turn back toward the east-northeast as it moves in tandem with the mid-latitude trough over the north Atlantic. The official forecast is in close agreement with the simple and corrected consensus models, TVCA and HCCA. Key Messages: 1. Hurricane conditions are expected in Bermuda Wednesday night and Thursday morning, with tropical-storm-force winds expected by Wednesday afternoon. Residents there should follow advice given by local officials. 2. Storm surge and dangerous breaking waves could cause coastal flooding Wednesday night and Thursday along the southern coast of Bermuda. 3. Swells will continue to affect the northwestern Bahamas and the southeastern coast of the United States from east-central Florida to North Carolina during the next couple of days, creating life- threatening surf and rip current conditions. FORECAST POSITIONS AND MAX WINDS INIT 18/0300Z 31.3N 71.0W 100 KT 115 MPH 12H 18/1200Z 32.0N 68.9W 100 KT 115 MPH 24H 19/0000Z 33.4N 65.5W 100 KT 115 MPH 36H 19/1200Z 36.0N 62.0W 90 KT 105 MPH 48H 20/0000Z 38.6N 60.2W 75 KT 85 MPH 72H 21/0000Z 42.5N 56.0W 55 KT 65 MPH...POST-TROP/EXTRATROP 96H 22/0000Z 44.0N 44.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 120H 23/0000Z 49.0N 26.0W 45 KT 50 MPH...POST-TROP/EXTRATROP $$ Forecaster Pasch