November 11, 1940: Armistice Day Blizzard
It was supposed to be a day to remember those who had served and sacrificed to bring an end to the Great War 22 years earlier. For many Minnesotans, however, Armistice Day of 1940 would be a day they would not soon forget. On that day, a fierce blizzard, unlike any the state had ever seen, caught many off guard, leaving 49 people across the state—and 154 total—dead.
The storm began as a strong area of low pressure that formed off the coast of the Pacific Northwest several days earlier. In fact, the same system that eventually developed into the Armistice Day Blizzard was responsible for strong winds on November 7 that contributed to the collapse of the newly built Tacoma Narrows Bridge in Washington. (For more on that event, see the Retrospect from the November/December 2005 issue of Weatherwise.)
By the morning of November 11, the low was centered over Eastern Kansas, with much of the Midwest well within the warm sector that existed between the warm front to the north and the cold front to the south. The temperature in Chicago, that morning registered a mild 55°F and rose to a high late that afternoon of 63°F before plummeting to a chilly 20°F at midnight. Minneapolis, was not nearly as warm, with a high of 38°F recorded just after midnight and the temperature falling steadily throughout the day to 26°F by noon and only 10°F by midnight on November 12. Light rain throughout the morning mixed briefly with freezing rain and sleet before changing to snow by noon. Winds increased as the pressure fell rapidly—gusting at times to 60 mph. The minimum pressure of the storm fell at least 28.7 millibars during the 24-hour period ending at 6:30 p.m. CST, qualifying it to be known by the meteorological moniker of a “bomb” cyclone. The lowest pressured recorded at Minneapolis during the passage of the storm was 29.83 inches, while Duluth, Minnesota, and La Crosse, Wisconsin, each reported record low pressure readings of 28.66 and 28.72 inches, respectively.
Caption: United States Weather Bureau Daily Weather Map for 7:30 a.m. EST, November 11, 1940. A strong area of low pressure centered over central Iowa developed into the Armistice Day Blizzard, which brought record low pressure, strong winds, and heavy snow across the Upper Midwest, with Minnesota among the hardest-hit areas.
It was hunting season in Minnesota, and many duck hunters took advantage of the day off and the mild weather that had prevailed up until that morning to head to the rivers or lakes in search of mallards and other waterfowl. With the forecast that morning calling for nothing more than colder temperatures and a few flurries, many of the hunters—and others—were simply unprepared for what was to come.
“The storm was fierce. The visibility was zero and by mid-afternoon the streetcars stopped running as did automobiles,” wrote Minneapolis resident Herbert Schoening in the Star Tribune on the anniversary of the storm in 2009. “There was an eery silence except for the howling wind.”
As the temperature dropped, the snow fell—and kept falling. By 6:30 p.m., 8.2 inches had fallen at Minneapolis, with a total of 16.8 inches reported at the storm's end. This set a storm total snowfall record that would stand for more than four decades and remains the sixth largest snowstorm on record for the Twin Cities. This total, however, was eclipsed by that recorded at the Weather Bureau's Cooperative Observer station at St. John's Abbey and University in Collegeville, about 75 miles north of Minneapolis. There, Father Casper Keogh recorded a total of 26.6 inches, the highest official snowfall total from the storm.
The Weather Bureau summarized the storm's impact on local communities in the Minnesota section of the November 1940 edition of its Climatological Data publication:
Hundreds of automobiles were abandoned in deep snow drifts, transportation facilities were at a standstill, and many people were unable to reach their homes. Train, bus, airplane, and streetcar services were interrupted from the afternoon of the 11th until the afternoon of the 14th, and some services were not fully restored until the 16th. There were many miles of snowdrifts. In the Wilmar area drifts as high as 20 feet were reported. Highway traffic was blocked generally throughout the areas affected. This condition improved very slowly, some side roads were not open to traffic until the close of November.
With losses statewide estimated at $1.5 million, including $500,000 in losses to turkey farms alone, the summary declared that the Armistice Day Blizzard would “go down into meteorological history as the most severe ever experienced during November in the state.” The storm ranks number two (after the Dust Bowl of the 1930s) on the Minnesota State Climatology Office's list of top weather events of the 20th century. Other states from Texas to New York also reported losses ranging from the tens to hundreds of thousands of dollars. Michigan reported losses totaling “several millions of dollars from the storm.”
Of the 49 Minnesotans who perished in the blizzard, 20 were hunters. Another 66 casualties were sailors aboard three ships that sank in Lake Michigan. The tragedy of the Armistice Day Blizzard shed a critical spotlight on the operations of the Weather Bureau, which at the time issued forecasts for locations throughout the Upper Midwest from its district office in Chicago, which did not operate on a 24-hour basis. In the aftermath of the storm and the overwhelming criticism that followed, the Weather Bureau instituted changes to increase the frequency and decentralization of its forecasts. Not only did the Chicago District Office move to round-the-clock operations, but increased staffing and responsibilities gave local offices, including the one in Minneapolis, the ability to better monitor conditions and provide forecasts—a system that, had it been in place in November 1940, might have saved lives.
Contributing Editor Sean Potter is a New York-based Certified Consulting Meteorologist (CCM), Certified Broadcast Meteorologist (CBM), and science writer with an interest in weather history.