ZCZC MIATCDEP2 ALL TTAA00 KNHC DDHHMM Hurricane Linda Discussion Number 34 NWS National Hurricane Center Miami FL EP122021 500 AM HST Wed Aug 18 2021 Satellite images indicate that Linda has been maintaining its intensity over the past 12 h or so. The hurricane has begun to lose some of its annular characteristics, as cloud tops in the northern semicircle are warmer than in the southern semicircle. However, the eye remains clear, and the overall structure has not changed much in the last 6 h. Final-T numbers from TAFB and SAB were both T-5.0/90 kt. Therefore, the initial intensity remains 90 kt for this advisory. Linda is currently over SSTs near 26C, but SSTs along the path of the cyclone will decrease to below 25C in about 12 h, then remain in the 24-25C range during the 12 to 48 h period. Vertical wind shear will remain low through 48 h, but mid-level relative humidity will decrease and become very dry over the next 48 h. Despite the favorable dynamics through 48 h, the unfavorable thermodynamics will likely cause weakening to below hurricane strength by 48 h. By 72 h, wind shear is forecast to increase and become strong by day 4 as Linda approaches a potent upper-level trough located to the northwest of Oahu. This will ultimately lead to the loss of deep convection, despite a slight increase in water temperatures along the cyclone's path at that time. Linda is forecast to become a post-tropical gale by Saturday morning. The NHC intensity forecast is essentially unchanged from the previous forecast and is in best agreement with the DSHP statistical-dynamical guidance. The initial motion is 280/11, which is unchanged from 6 h ago. There is no significant change to the previous forecast track or reasoning. A well-established subtropical ridge should steer Linda in a westward to west-northwestward fashion during the next 5 days. The new NHC forecast track is virtually unchanged from the previous one and is in best agreement with the TVCN and HCCA consensus models. Linda is forecast to cross into the Central Pacific in about 36 h and is expected to pass to the north of the Hawaiian Islands as a post-tropical gale late Sunday into Monday. FORECAST POSITIONS AND MAX WINDS INIT 18/1500Z 18.2N 131.8W 90 KT 105 MPH 12H 19/0000Z 18.9N 133.9W 85 KT 100 MPH 24H 19/1200Z 19.7N 136.9W 75 KT 85 MPH 36H 20/0000Z 20.3N 140.0W 65 KT 75 MPH 48H 20/1200Z 20.8N 142.9W 55 KT 65 MPH 60H 21/0000Z 21.2N 145.6W 45 KT 50 MPH 72H 21/1200Z 21.6N 148.0W 40 KT 45 MPH...POST-TROPICAL 96H 22/1200Z 22.6N 152.5W 35 KT 40 MPH...POST-TROPICAL 120H 23/1200Z 23.5N 157.3W 35 KT 40 MPH...POST-TROPICAL $$ Forecaster Hagen/Cangialosi NNNN