Historic El Niño Expected to Peak, Bringing Varied Winter Weather to Colorado
Colorado is anticipating a winter influenced by a historic El Niño event, which is expected to peak in December or January as one of the strongest on record, potentially surpassing all events since 1950. The European seasonal model forecasts the 3-month index above +3 °C, and NOAA gives 70–83% odds of it beating every event since 1950. This 'east-based' El Niño, with its warmest waters unusually far east towards South America, is known to have significant effects on West Coast weather. For Colorado, the forecast indicates a split pattern: the eastern plains and southern mountains are expected to lean wet, while the northern and central mountains may experience drier or neutral conditions. Boulder and Denver are projected to be near normal through mid-winter, then tilt wetter into late winter and March, with models giving a 3-in-4 chance of a wetter-than-normal November–March. Historically, strong El Niño winters in Boulder have been 'feast or famine' for snowfall, often decided by spring storms.
