110th Anniversary of the Great Blue Norther, the U.S.’s most powerful cold front

TULSA, Okla. — On Nov. 11, 1911, the most dramatic and even deadly storm system in U.S. history hit the Midwest.

From Oklahoma to Wisconsin, temperatures dropped more than 30 degrees in a matter of minutes. In Wisconsin, a deadly F4 tornado struck just an hour before a blizzard began in the same location.

From Summer to full-on Winter, temperatures plummeted around 70 degrees in just a matter of hours in Green Country. Tulsa set a then-record high of 85 degrees in November, to a record low of 15 degrees on Nov. 11. Those records still stand today.

A dust storm accompanied the severe cold front in Oklahoma.

In Springfield, Missouri, rain, hail, sleet and snow were all reported within several hours of one another that day.

These cold fronts form from three main factors:

  • A large and deep pocket of polar air. By November, the North Pole is cooling rapidly with the loss of daylight. This allows that air to get colder and denser.
  • Lingering warm air further south. If you get too late in the season, the air at lower latitudes will be much cooler as well.
  • Strong wave in the jet stream. This creates a low pressure spanning the altitudes, which can latch onto that polar air and then force it southward. As the low pressure deepens, this causes a major displacement of that polar air and that cold, dense air surges south.

These factors were all extreme in 1911, and it made the change so extreme across the country that November day.

With modern forecast and communication technology, we can monitor cold fronts like these and be prepared for these abrupt and harsh weather changes.

November is the most notorious months for these big temperature swings and a cold front like that can and will happen again.