Latest NOAA and ECMWF ensemble forecasts drive trader consensus toward mid-50s highs for Chicago on March 24, with 54-55°F and 52-53°F each at 26.5% reflecting model means around 54°F under a building upper-level ridge fostering mild southerly flow. The 56°F+ outcome at 29.5% gains from outlier GFS runs showing stronger warm advection and clearer skies, while lower bins like 50-51°F (17%) account for potential marine layer clouds or diurnal timing shifts at O'Hare Airport. Differentiating factors include jet stream waviness—traders weigh ridge amplification for upside warmth against boundary layer mixing limits—against historical March volatility, where 10-15°F spreads are common pre-event. Upcoming 12z model updates could sharpen odds.