####018002833#### WTPZ44 KNHC 020232 TCDEP4 Tropical Storm Pilar Discussion Number 18 NWS National Hurricane Center Miami FL EP192023 1000 PM CDT Wed Nov 01 2023 Deep convection near the center of Pilar has diminished significantly this evening. Cloud tops associated with the cyclone are now generally warmer than -50 deg C. This degradation in the cloud structure could be at least partially be caused by the system's passage over upwelled ocean waters near the coast. Another factor could be some disruption due to the influence of a nearby Tehuantepec gap wind event. Given the decrease in convection, it is assumed that some weakening has occurred and the current intensity is set at 40 kt for this advisory. This is close to the mean of final T-numbers and CI numbers from TAFB and SAB. Center fixes indicate that the westward track is continuing with a motion estimate of 270/10 kt. A prominent mid-level subtropical ridge is expected to remain north of Pilar, and strengthen further, during the next few days. This should force a westward to west-southwestward motion with some increase in forward speed. The official track forecast is again a little faster than the previous one and is a blend of the simple and corrected dynamical model consensus predictions. The gap wind event and easterly vertical wind shear could cause some additional weakening during the next day or so. Later in the forecast period, moderate shear and marginal thermodynamic conditions are likely to inhibit strengthening. The NHC forecast shows very slow weakening through the period. However, there is a possibility that the system will degenerate into a remnant low or a trough within the next 5 days. Key Messages: 1. The combination of previous heavy rainfall and any additional rainfall from Pilar may produce flash and urban flooding, along with mudslides in areas of higher terrain of the Pacific coast from El Salvador into southern Guatemala overnight. 2. Swells generated by Pilar and strong winds near the Gulf of Tehuantepec are expected to continue affecting the Pacific coast of Central America during the next day or two. These swells are likely to cause life-threatening surf and rip current conditions. FORECAST POSITIONS AND MAX WINDS INIT 02/0300Z 12.4N 92.6W 40 KT 45 MPH 12H 02/1200Z 11.7N 94.8W 40 KT 45 MPH 24H 03/0000Z 10.8N 97.8W 40 KT 45 MPH 36H 03/1200Z 9.9N 101.0W 35 KT 40 MPH 48H 04/0000Z 9.4N 104.1W 35 KT 40 MPH 60H 04/1200Z 9.5N 106.8W 35 KT 40 MPH 72H 05/0000Z 9.7N 109.2W 35 KT 40 MPH 96H 06/0000Z 10.5N 113.1W 30 KT 35 MPH 120H 07/0000Z 11.3N 116.0W 30 KT 35 MPH $$ Forecaster Pasch