ZCZC MIATCDEP4 ALL TTAA00 KNHC DDHHMM Tropical Storm Pilar Discussion Number 15 NWS National Hurricane Center Miami FL EP192023 400 AM CDT Wed Nov 01 2023 Deep convection associated with Pilar has increased over the western portion of the circulation this morning. Despite some continued east-southeasterly shear over the cyclone, the cold dense overcast has begun to expand eastward, and proxy-visible and shortwave infrared satellite images suggest the center is no longer exposed. The latest objective intensity estimates seem too low based on recent satellite trends and yesterday's scatterometer data. A blend of subjective Dvorak current intensity estimates from SAB and TAFB support holding the initial intensity at 50 kt. Satellite images and recent fixes suggest Pilar is now moving northwestward (325/3 kt). A more westward motion is expected later today, followed by an acceleration to the west-southwest through Friday as a mid-level ridge builds over central Mexico. This motion away from land should be reinforced by the low-level northerly flow well downstream of a strong Gulf of Tehuantepec gap wind event. The only notable change to the NHC track forecast is a faster forward speed during the first few days of the forecast, which is supported by the latest TVCE and HCCA consensus aids. While the satellite structure of Pilar has improved during the diurnal maximum period, the storm will continue to be impacted by moderate shear during the next couple of days. Also, the regional hurricane models show that the slow-moving cyclone has upwelled some cooler waters, and Pilar is forecast to move over this cool wake during the next day or two. In addition, model-simulated satellite imagery indicates the storm's convection could be disrupted while it encounters the drier low-level flow downstream of the ongoing gap wind event. Not surprisingly, most of the intensity guidance shows some gradual weakening during the next couple of days, and the official NHC forecast follows suit. Later in the period, there is a large spread in the intensity guidance, as the statistical-dynamical aids show strengthening while the global and regional hurricane models are much weaker. Similar to the previous prediction, this forecast stays near the simple consensus (IVCN) and shows little intensity change from days 3-5. Key Messages: 1. Heavy rains from Pilar will produce flash and urban flooding, along with mudslides in areas of higher terrain of the Pacific coast of Central America from southern El Salvador, across southern Honduras, western Nicaragua into northern Costa Rica through today. 2. Tropical storm conditions are possible along portions of the Pacific coast of El Salvador, Honduras, and Nicaragua, where a Tropical Storm Watch remains in effect. 3. Swells generated by Pilar will continue to affect the Pacific coast of Central America during the next couple of days. These swells are likely to cause life-threatening surf and rip current conditions. FORECAST POSITIONS AND MAX WINDS INIT 01/0900Z 12.3N 89.9W 50 KT 60 MPH 12H 01/1800Z 12.1N 90.6W 50 KT 60 MPH 24H 02/0600Z 11.7N 92.5W 45 KT 50 MPH 36H 02/1800Z 11.0N 95.2W 45 KT 50 MPH 48H 03/0600Z 10.2N 98.1W 40 KT 45 MPH 60H 03/1800Z 9.6N 101.0W 40 KT 45 MPH 72H 04/0600Z 9.2N 103.5W 40 KT 45 MPH 96H 05/0600Z 9.5N 108.5W 40 KT 45 MPH 120H 06/0600Z 10.0N 111.5W 35 KT 40 MPH $$ Forecaster Reinhart NNNN