ZCZC MIATCDEP5 ALL TTAA00 KNHC DDHHMM Tropical Storm Lidia Discussion Number 20 NWS National Hurricane Center Miami FL EP152023 900 PM MDT Sat Oct 07 2023 The satellite presentation of Lidia has improved since yesterday. Recent AMSR2 and SSMIS passive microwave images show signs of a mid-level eye feature in the 89 GHz channel. However, the vortex still appears tilted, with the low-level 37 GHz center situated to the northeast of the mid-level center. While the upper-level outflow is still restricted on the eastern side of the storm, the center has been located deeper underneath the cold convective canopy today. As a result, the satellite intensity estimates have risen, but they seem a little high based on the earlier ASCAT data. The initial intensity is raised to 60 kt, which is in best agreement with recent UW-CIMSS SATCON and D-PRINT estimates. The moderate easterly shear over Lidia is forecast to persist for another 12-24 h, then weaken into early next week. The weaker shear should allow Lidia to become more vertically aligned and strengthen within a diffluent upper-level environment while moving over very warm waters. Most of the intensity guidance shows strengthening after 24 h while Lidia moves toward the coast of Mexico. The regional hurricane models (HAFS, HWRF, HMON) show some potential for significant intensification, and overall it appears more likely that Lidia reaches the coast at hurricane strength early next week. As a result, the NHC intensity forecast has been raised at 24-72 h, though it still lies below the IVCN and HCCA aids. Given the large spread noted in the intensity guidance, future adjustments are certainly possible. Lidia has not moved much since the last advisory, and its estimated initial motion is west-northwestward or 285/3 kt. The storm is expected to slowly turn northward on Sunday while moving around the western periphery of a mid-level ridge. Then, the southwesterly flow ahead of an upper-level trough to the north will cause Lidia to accelerate northeastward toward the west-central coast of Mexico. The largest spread in the track models is related to the forward speed of Lidia while it interacts with the trough. The GFS brings Lidia inland over mainland Mexico about 24 h earlier than the rest of the global models, and thus there is more uncertainty in the longer-range track forecast. For now, the NHC track follows a consensus approach and lies between the TVCE and HCCA aids, similar to but slightly faster than the previous prediction. Key Messages: 1. Lidia is forecast to strengthen to a hurricane while it moves toward the west-central coast of Mexico early next week. 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 as early as Sunday. 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 08/0300Z 16.1N 112.6W 60 KT 70 MPH 12H 08/1200Z 16.8N 112.7W 60 KT 70 MPH 24H 09/0000Z 17.6N 112.6W 65 KT 75 MPH 36H 09/1200Z 18.3N 111.9W 65 KT 75 MPH 48H 10/0000Z 18.9N 110.5W 70 KT 80 MPH 60H 10/1200Z 19.8N 108.5W 75 KT 85 MPH 72H 11/0000Z 21.1N 105.9W 75 KT 85 MPH 96H 12/0000Z 24.0N 101.5W 30 KT 35 MPH...POST-TROP/INLAND 120H 13/0000Z...DISSIPATED $$ Forecaster Reinhart NNNN