Issued at 800 PM PDT Sun Oct 26 2025
000 WTPZ43 KNHC 270239 TCDEP3 Tropical Storm Sonia Discussion Number 10 NWS National Hurricane Center Miami FL EP182025 800 PM PDT Sun Oct 26 2025 Satellite imagery indicates that Sonia has degraded during the past 12 to 24 h as persistent moderate southerly wind shear has displaced deep convection mostly north of the low-level circulation center. The circulation is now partially exposed on the southern edge of the deep convection. Based on a blend of the subjective Dvorak and objective intensity estimates, the initial intensity is set at 40 kt. Sonia is moving west-northwestward at about 295/5 kt, and this general motion is expected to persist over the next day or so, as the subtropical ridge remains positioned to the north. By Tuesday, Sonia should gradually turn toward the west as it becomes a shallow system embedded within the low-level trade-wind flow. The NHC track forecast is little changed from the previous one and remains close to the multi-model consensus aids. Moderate southerly wind shear continues to affect Sonia and is expected to generally hold steady during the next couple of days, if not increase slightly. This, combined with cooler waters and a drier, more stable environment ahead of the cyclone, should result in a gradual weakening trend beginning within the next 12 to 24 hours. Simulated satellite imagery from the GFS and ECMWF shows convection diminishing significantly by Tuesday, suggesting that Sonia will lose organized deep convection and become a post-tropical remnant low by that time. Dissipation is expected by Wednesday as the remnant low continues westward and opens into a trough. The updated NHC intensity forecast closely follows the consensus aids and remains similar to the previous one. FORECAST POSITIONS AND MAX WINDS INIT 27/0300Z 14.1N 120.0W 40 KT 45 MPH 12H 27/1200Z 14.3N 120.6W 40 KT 45 MPH 24H 28/0000Z 14.6N 121.7W 35 KT 40 MPH 36H 28/1200Z 14.8N 123.2W 35 KT 40 MPH 48H 29/0000Z 14.8N 124.7W 30 KT 35 MPH...POST-TROP/REMNT LOW 60H 29/1200Z 14.7N 126.6W 25 KT 30 MPH...POST-TROP/REMNT LOW 72H 30/0000Z...DISSIPATED $$ Forecaster Gibbs (CPHC)
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