ZCZC MIATCDEP5 ALL TTAA00 KNHC DDHHMM Tropical Storm Lidia Discussion Number 21 NWS National Hurricane Center Miami FL EP152023 300 AM MDT Sun Oct 08 2023 Overnight GOES-18 Proxy-Vis satellite imagery and a recent SSMIS microwave overpass indicate that Lidia's vertical structure remains slightly tilted toward the north, with the center located near the northern edge of the cloud mass. The initial intensity is held at 60 kt for this advisory and is based primarily on UW-CIMSS objective intensity techniques of the Deep Multispectral and IR Intensity TC estimators, which both yield an intensity estimate of 59 kt. The statistical GFS/ECMWF SHIPS intensity guidance indicates that the deep-layer shear impeding Lidia's intensification rate during the past few days will decrease soon. This more conducive upper wind pattern should cause the cyclone to become a more vertically coherent system. Therefore, strengthening is expected while Lidia traverses warm (29-30C) sea surface temperatures, and Lidia is forecast to become a hurricane early Monday. The NHC intensity is based on a blend of the IVCN consensus and the Decay SHIPS and is just below the HFIP HCCA corrected consensus beyond the 48-hour period, which indicates a peak of 85 kt. Lidia is drifting generally north-northwestward or 335/2 kt, and this slow generally northward motion is expected to continue through today while the cyclone rounds the western periphery of a subtropical ridge. On Monday, Lidia is forecast to turn toward the north-northeast to northeast and accelerate toward the west-central coast of Mexico in response to a major shortwave trough approaching the system from the northeast. No significant changes were made to the previous advisory and the new official track forecast lies closely to the various multi-model consensus aids. Key Messages: 1. Lidia is forecast to strengthen to a hurricane while it moves toward the west-central coast of Mexico on Tuesday. There is an increasing risk of strong winds and heavy rain for the Islas Marias and portions of the west-central coast of Mexico. Interests in these locations should closely monitor the latest forecast updates, as watches could be required later today or tonight. 2. Swells from Lidia will cause dangerous surf and rip current conditions along the west coast of Mexico and the Baja California peninsula during the next several days. FORECAST POSITIONS AND MAX WINDS INIT 08/0900Z 16.4N 112.5W 60 KT 70 MPH 12H 08/1800Z 17.1N 112.6W 60 KT 70 MPH 24H 09/0600Z 17.9N 112.3W 65 KT 75 MPH 36H 09/1800Z 18.6N 111.3W 65 KT 75 MPH 48H 10/0600Z 19.3N 109.4W 75 KT 85 MPH 60H 10/1800Z 20.3N 106.9W 75 KT 85 MPH 72H 11/0600Z 21.9N 103.7W 35 KT 40 MPH...INLAND 96H 12/0600Z...DISSIPATED $$ Forecaster Roberts NNNN