Trader uncertainty in the San Francisco March 24 high temperature market stems from ensemble forecast models showing tight clustering around 62-65°F amid conflicting signals on marine layer persistence versus inland heat advection. National Weather Service guidance from GFS and ECMWF runs projects a daytime max near 64°F under weak high-pressure ridging, but coastal stratus clouds—driven by cool Pacific sea surface temperatures and northwesterly winds—could cap highs below 62°F, matching March climatology (historical median ~62°F). Key differentiators include the nocturnal low's recovery rate and 500-mb height anomalies; traders await 12Z model updates, with 64-65°F edging slightly ahead on subsidence inversion forecasts despite even market-implied odds.