ZCZC MIATCDAT3 ALL TTAA00 KNHC DDHHMM Hurricane Lee Discussion Number 13 NWS National Hurricane Center Miami FL AL132023 1100 AM AST Fri Sep 08 2023 The satellite presentation of Lee degraded somewhat this morning. The small eye has become cloud filled and the overall cloud pattern has become more asymmetric. There has been no indication of concentric eyewalls so far, and the recent filling appears to be the result of some moderate (15-20 kt) southwesterly shear as diagnosed by a shear analysis from UW/CIMSS. Within the past hour or so, the small eye has once again become a little better defined. Both NOAA and Air Force Reserve Hurricane Hunter aircraft have been in the storm this morning. The NOAA aircraft has measured a peak 8000 ft flight-level wind of 143 kt, and the Air Force plane has found peak 700-mb flight level winds of 132 kt. SFMR surface estimates have peaked in the 130-143 kt range. The pressure has risen to around 942 mb. Using a blend of these data the initial intensity is set at 135 kt. Fluctuations in intensity like what has occurred this morning are not uncommon in intense hurricanes. Although Lee's current intensity is lower than the overnight peak, the hurricane remains very powerful. The latest global model guidance suggests that the moderate shear over the hurricane is likely to continue during the next day or so. This along with potential eye wall replacement cycles are likely to result in additional fluctuations in intensity during that time, which are very difficult to time and predict. By later this weekend, the upper-level wind pattern could become a little more conducive and some restrengthening is possible. Regardless of exact details of the intensity forecast, confidence is high that Lee will remain a powerful hurricane during the next several days. Lee has been moving west-northwestward at about 11 kt. The hurricane should continued to be steered west-northwestward to the south of a subtropical ridge over the central Atlantic. The western extent of the ridge is forecast to weaken by early next week, and Lee's forward speed is expected to slow considerably around days 3-5. The track guidance continues to be tightly clustered during the forecast period, and the NHC track is near the middle of the guidance envelope. KEY MESSAGES: 1. Lee's core is expected to move well north of the northern Leeward Islands, the Virgin Islands, and Puerto Rico this weekend and early next week. 2. Dangerous surf and life-threatening rip currents are likely in the northern Leeward Islands beginning today. These conditions will spread westward and northward, affecting Puerto Rico, Hispaniola, the Turks and Caicos, the Bahamas, and Bermuda through the weekend. 3. It is way too soon to know what level of impacts, if any, Lee might have along the U.S. East Coast, Atlantic Canada, or Bermuda late next week, particularly since the hurricane is expected to slow down considerably over the southwestern Atlantic. Regardless, dangerous surf and rip currents are expected along most of the U.S. East Coast beginning Sunday. Continue to monitor updates to Lee's forecast during the next several days. FORECAST POSITIONS AND MAX WINDS INIT 08/1500Z 18.2N 54.5W 135 KT 155 MPH 12H 09/0000Z 19.0N 56.1W 135 KT 155 MPH 24H 09/1200Z 20.0N 57.9W 130 KT 150 MPH 36H 10/0000Z 20.8N 59.4W 125 KT 145 MPH 48H 10/1200Z 21.5N 60.8W 125 KT 145 MPH 60H 11/0000Z 22.1N 62.0W 125 KT 145 MPH 72H 11/1200Z 22.7N 63.1W 125 KT 145 MPH 96H 12/1200Z 23.5N 65.5W 120 KT 140 MPH 120H 13/1200Z 24.8N 67.5W 115 KT 130 MPH $$ Forecaster Brown NNNN