Recent National Weather Service and ensemble forecasts indicate a Pacific frontal system arriving Thursday night into Friday, bringing widespread rain, elevated cloud cover, and southwesterly winds to the Seattle area that will limit nocturnal radiative cooling and hold the September 25 low near 46–51 °F. Model consensus from sources such as the GFS and ECMWF shows modest spread in timing and intensity of showers, which directly affects how much temperatures fall after midnight; stronger or more persistent rain tends to produce readings in the upper 40s, while lighter or delayed precipitation allows brief clearing and readings near 52 °F. Historical September climatology places the average low around 51 °F, so the current setup represents a modest cool anomaly driven by the approaching trough. With market-implied odds clustered between the 45–52 °F bins, traders are pricing the remaining uncertainty in exact minimum temperature and resolution criteria. Updated model runs and local observations over the next 48 hours will be the key catalysts.