ZCZC MIATCDEP5 ALL TTAA00 KNHC DDHHMM Tropical Storm Lidia Discussion Number 19 NWS National Hurricane Center Miami FL EP152023 300 PM MDT Sat Oct 07 2023 Recent partial ASCAT passes and infrared satellite imagery indicate that the center of Lidia has been located well underneath the large, cold convective canopy for the past several hours. This suggests that the northeasterly to easterly shear may have decreased slightly compared to yesterday. However, recent SSMIS and GMI passes indicate that the structure has not improved much. The recent ASCAT passes also suggest that the winds have not increased yet. Despite subjective Dvorak estimates ranging from 65 to 77 kt and objective estimates ranging from 51 to 63 kt, the intensity is held at 55 kt for this advisory based on the ASCAT data. There is not much change to the track forecast reasoning. The microwave and ASCAT data indicate that Lidia has not made any significant northward progress yet. The motion is estimated at 280/3 kt. A gradual turn to the north is expected to occur over the next 24 h, after which time, the cyclone is expected to begin interacting with an approaching trough from the north. This interaction will result in an acceleration early next week toward the northeast and in the general direction of west-central Mexico. The NHC forecast is similar to the previous forecast through 60 h, but shows a faster northeastward motion around the time of landfall and after landfall, and is in best agreement with the TVCE consensus aid. It should be noted that there remains significant along-track spread in the guidance, meaning that there is some uncertainty in the timing of landfall. Moderate easterly shear is likely to inhibit significant intensification through early Sunday. However, the shear is expected to briefly relax late Sunday through Monday night, as the cyclone moves northward over warm sea-surface temperatures. Lidia is therefore forecast to intensify to hurricane strength by Monday. It should be noted that Lidia could intensify a bit more quickly than forecast, considering the center is now well underneath the cold convective canopy. As the storm approaches landfall in Mexico, southwesterly shear is expected to increase, but this shear may not have time to affect the cyclone much before it makes landfall. Furthermore, it should be noted that the deterministic GFS global model depicts very low central pressures, suggesting Lidia could maintain hurricane intensity through landfall. Other reliable statistical models and consensus aids are not as aggressive. The NHC forecast is similar to the prior forecast, except it brings Lidia to hurricane strength a bit sooner. Confidence in the intensity forecast is below average. Interests in west-central Mexico should remain attentive to forecast updates in the coming days. FORECAST POSITIONS AND MAX WINDS INIT 07/2100Z 16.1N 112.5W 55 KT 65 MPH 12H 08/0600Z 16.6N 112.7W 55 KT 65 MPH 24H 08/1800Z 17.4N 112.8W 60 KT 70 MPH 36H 09/0600Z 18.2N 112.5W 60 KT 70 MPH 48H 09/1800Z 18.8N 111.6W 65 KT 75 MPH 60H 10/0600Z 19.3N 110.0W 65 KT 75 MPH 72H 10/1800Z 20.3N 107.7W 65 KT 75 MPH 96H 11/1800Z 22.9N 103.3W 40 KT 45 MPH...INLAND 120H 12/1800Z...DISSIPATED $$ Forecaster Hagen/Berg NNNN