Recent National Weather Service guidance and ensemble model runs for Seattle on August 10 point to a high in the mid-to-upper 70s, consistent with the market’s tight clustering around 76–79°F. A weakening upper ridge combined with strengthening onshore flow from the Pacific is introducing cooler marine air, moderating temperatures from earlier August warmth and keeping readings near or slightly above the 76°F climatological average. Small differences in cloud cover timing, boundary-layer mixing, and the precise strength of the marine push create the narrow spread between the 76–77°F and 78–79°F bins, while lower-probability warmer outcomes would require suppressed onshore flow or delayed cloud development. Updated model cycles and the evening forecast discussion remain the key near-term catalysts.