Recent National Weather Service forecasts highlight a persistent heat dome and weak onshore flow keeping Southern California well above seasonal normals, yet increased moisture from the remnants of Tropical Storm Iselle is introducing extensive cloud cover and a 20% chance of showers and thunderstorms over coastal Los Angeles on August 27. These conditions are expected to moderate maximum temperatures at marine-influenced stations such as LAX, where official guidance points to highs in the lower to mid-80s—aligning with the market’s leading 84–87°F bins—while inland valleys remain much hotter. Model consensus and recent observations show the marine layer remaining shallow but persistent enough to limit peak heating, with any breaks in clouds offering only modest upside risk. The implied probabilities therefore reflect traders weighting the balance between residual heat advection and the cooling influence of tropical moisture and cloudiness against historical late-August coastal averages near 77°F.