####018002922#### WTPZ45 KNHC 031450 TCDEP5 Tropical Storm Lidia Discussion Number 2 NWS National Hurricane Center Miami FL EP152023 900 AM MDT Tue Oct 03 2023 Lidia continues to have bursts of deep convection this morning, with cold cloud tops to -80 degrees Celsius. An earlier AMSR2 microwave pass depicted a curved banding feature developing to the west and north of the low-level center, as Lidia's convection continues to organize. A blend of subjective and objective satellite intensity estimates are around 35 kt, which is in good agreement with the earlier scatterometer passes from this morning. Therefore, the initial intensity for this advisory remains 35 kt. The system is moving west-northwest at 300/8 kt, around the southern edge of a mid-level ridge located over Mexico. A mid- to upper-level trough to the northwest will begin to weaken the ridge allowing Lidia to move more northwest to north-northwest the next few days. The guidance envelope is in fairly good agreement with this general motion the next 48 hours or so. Beyond day 2, there is a little more uncertainty in the forecast as models differ on the timing of the mid-level ridge building back in as the trough lifts out of the area. The GFS and ECMWF turn the system more westward as the ridge strengthens, compared to some of the hurricane regional models, like HAFS-A and HAFS-B, which continue a more northward motion. The NHC forecast is closer to the ECMWF/GFS solutions through the end of the forecast period, with a slow turn westward. Lidia is currently dealing with some moderate easterly vertical wind shear. The ECMWF/GFS SHIPS guidance depicts that moderate shear will remain over the system throughout the forecast period. The system will remain over fairly warm sea-surface temperatures near 30 C, and a favorable upper-level wind pattern with divergence aloft. RI parameters are slightly lower in the short-term compared to the previous cycle. However, the ECMWF-SHIPS has a 55 percent chance of a 65-kt increase in 72 hours. While this will not be explicitly forecast we will continue to monitor these parameters and trends in subsequent forecasts. The NHC intensity forecast is fairly similar to the previous showing gradual intensification throughout the period, and lies near the IVCN simple consensus aid. FORECAST POSITIONS AND MAX WINDS INIT 03/1500Z 12.3N 107.6W 35 KT 40 MPH 12H 04/0000Z 13.1N 108.5W 40 KT 45 MPH 24H 04/1200Z 14.0N 109.3W 45 KT 50 MPH 36H 05/0000Z 14.8N 109.7W 50 KT 60 MPH 48H 05/1200Z 15.4N 110.0W 55 KT 65 MPH 60H 06/0000Z 15.9N 110.4W 60 KT 70 MPH 72H 06/1200Z 16.0N 111.0W 65 KT 75 MPH 96H 07/1200Z 15.9N 112.3W 65 KT 75 MPH 120H 08/1200Z 15.9N 114.0W 65 KT 75 MPH $$ Forecaster Kelly/Stevenson