Recent NWS and private model guidance for Seattle points to a transition from cool, showery conditions on September 13–14 toward partly to mostly sunny skies on the 15th, supporting market-implied odds clustered around 64–67°F. An upper-level low has kept daytime highs 5–10°F below the late-September average near 71°F, with northerly winds and residual moisture limiting warming; forecasters now expect gradual clearing and light northerly flow to allow modest recovery into the mid-60s. Resolution hinges on the precise timing of any morning clouds or drizzle and the afternoon peak, with ensemble spreads indicating a realistic 4–6°F range across guidance. Updated NWS and NOAA model runs over the next 48 hours will refine these thresholds ahead of market close.