Recent National Weather Service and model guidance highlight uncertainty in the marine layer depth and onshore flow strength as the main drivers behind the closely matched probabilities for 76–79°F. Persistent coastal stratus and moderate northwest winds are expected to limit daytime heating in downtown Los Angeles, while any shallowing of the layer or slight offshore shift could allow temperatures to reach the upper 70s or low 80s. Ensemble spreads remain modest this close to the event, with historical July climatology (normal high near 82°F) providing context but current pattern favoring below-average readings. Updated model runs and morning observations on July 19 will refine the final official maximum used for market resolution.