ZCZC MIATCDAT3 ALL TTAA00 KNHC DDHHMM Hurricane Lee Discussion Number 33 NWS National Hurricane Center Miami FL AL132023 1100 AM AST Wed Sep 13 2023 Lee continues to exhibit concentric eyewalls, but there are some dry slots between those features. An SSMIS microwave image around 10Z showed that both eyewalls were open, however, recent infrared satellite images indicate that the inner eyewall appears to be becoming better organized during the past few hours. The initial wind speed is held at 100 kt, but this is near the high end of the latest satellite intensity estimates. The Air Force Hurricane Hunters are scheduled to investigate Lee this afternoon, and the data they collect should provide a better assessment of the hurricane's intensity and structure. Satellite images suggest that Lee seems to be beginning its northward turn on the western side of a subtropical ridge situated over the central Atlantic. The latest initial motion estimate is 345/6 kt. Lee should gradually increase in forward speed while moving northward on the west side of the ridge during the next couple of days, taking the core of the system to the west of Bermuda Thursday and Thursday night. The combination of a shortwave trough and a building ridge extending into Atlantic Canada could cause Lee to turn slightly to the left Friday night and Saturday, which will likely bring Lee close to southeastern New England before it reaches Maine and Atlantic Canada later in the weekend. Confidence is increasing in the forecast track, and the model spread is mostly along-track, associated with the system's forward speed/timing. Overall, little change was made to the previous NHC track forecast, and it remains very near the various consensus models. Lee is expected to gradually weaken as it moves into an environment of increasing vertical wind shear, slightly drier air, and over progressively cooler waters during the next few days. However, the large size of the system suggests that the weakening process should be slow. In addition, Lee is expected to grow in size as it gains latitude during the next few days. The NHC intensity forecast is largely the same as the previous one and fairly close to the HCCA and IVCN models. Regardless of the details, there is high confidence that Lee will be a large hurricane near the coast of New England Friday night and Saturday. It should again be noted that the 34- and 50-kt wind speed probabilities beyond 36 hours in the text and graphical products are likely underestimating the risk of those winds occurring. This is because the forecast wind field of Lee is considerably larger than average compared to the wind field used to derive the wind speed probability product. KEY MESSAGES: 1. Dangerous surf and life-threatening rip currents will affect portions of the northern Leeward Islands, the Virgin Islands, Puerto Rico, Hispaniola, the Turks and Caicos Islands, the Bahamas, Bermuda, the U.S East Coast, and Atlantic Canada into the weekend. 2. Tropical storm conditions, heavy rainfall, and high surf are expected to impact Bermuda beginning early Thursday, and a Tropical Storm Warning is in effect for the island. 3. There is an increasing risk of wind, coastal flooding, and rain impacts from Lee in portions of New England and Atlantic Canada beginning on Friday and continuing through the weekend. Watches will likely required for portions of these areas later today or tonight. Due to Lee's large size, hazards will extend well away from the center, and there will be little to no significance on exactly where the center reaches the coast. FORECAST POSITIONS AND MAX WINDS INIT 13/1500Z 26.4N 67.2W 100 KT 115 MPH 12H 14/0000Z 27.6N 67.7W 95 KT 110 MPH 24H 14/1200Z 29.6N 68.2W 90 KT 105 MPH 36H 15/0000Z 31.8N 68.2W 85 KT 100 MPH 48H 15/1200Z 34.6N 67.6W 80 KT 90 MPH 60H 16/0000Z 37.9N 67.1W 75 KT 85 MPH 72H 16/1200Z 41.1N 67.2W 70 KT 80 MPH 96H 17/1200Z 46.1N 66.6W 50 KT 60 MPH...POST-TROP/INLAND 120H 18/1200Z 52.1N 56.4W 35 KT 40 MPH...POST-TROP/INLAND $$ Forecaster Cangialosi NNNN