The Armistice Day Blizzard of 1940

  • Clearing snow after the Armistice Day blizzard of 1940 in Madison, MN. Source: NOAA

    Aftermath of the Armistice Day blizzard of 1940 in Hibbing, MN. Source: NOAA

    Snow covers Armistice Day wreaths and crosses at this memorial near Thirsk. Source: John Giles/PA Wire

  • The Armistice Day Blizzard of 1940
    08.11.2014 15:41

    As Remembrance Sunday approaches and we take time to remember the members of the armed forces who died in the line of duty, a look back into weather history illustrates that this time of year is associated with particularly interesting and extreme weather events, most notably the Armistice Day Blizzard of 1940 in the Midwest of the United States.

    By the 11th November each year the temperature contrast across the mid-latitudes becomes increasingly sharp. Residual summer heat interacts with increasing cold in northern latitudes and a consequence of this tight temperature gradient is the development of extra-tropical cyclones. These cyclones can grow into large and intense storms that have the potential to wreak havoc across the mid-west US and Great Lakes.

    As a result of this temperature contrast, a number of severe weather events have occurred in the period around Armistice Day. A particularly extreme event occurred on the 11th November 1940 in the Midwest region of the US. A rapidly developing low pressure system tracked from Kansas City, Minnesota northeast into the Upper Great Lakes. The rapidly deepening low pressure system brought new low pressure records to Charles City, Indianapolis (979hPa), La Crosse, Wisconsin (972hPa), and Duluth, Minnesota (970hPa).

    Jeff Boyne from the National Weather Service describes how the weather developed that morning, “Armistice Day began with blue skies and temperatures in the 40s and 50s (5-15C). The weather forecast for that morning was for colder temperatures and a few flurries. The day was so nice that duck hunters dressed in short-sleeved shirts rushed to the marshes along the Mississippi River early that morning.”

    However, during the afternoon the weather deteriorated rapidly with the air temperature dropping by as much as 40F (30C) in 24 hours. Winds strengthened and rain quickly turned to snow, blizzard conditions followed very rapidly and ice as thick as an inch coated poles and phone lines.

    The greatest snow total was recorded in Collegeville, Minnesota with 26.6 inches (68cm) measured. Twenty foot drifts were reported near Willmar in Minnesota whilst winds averaged 25 mph for over 24 hours and gusts above 60mph were recorded.

    In total the storm claimed 145 lives; as many as 50 duck hunters were killed along the Mississippi River while over 60 sailors died on three freighters on Lake Michigan. Local industry suffered large losses with a great deal of livestock and poultry killed, 1.5 million Turkeys were said to have perished.

    Weather forecasting for the region which had originated in Chicago was expanded to include 24-hour coverage and more local forecasting offices were created.

    Armistice Day (11th November) this year is likely to see a significant cold outbreak again in the mid-west US with the development of an extra-tropical depression. However, the latest numerical weather model output suggests that the system will not be anywhere near as intense as the 1940’s Armistice Day Blizzard.

    Meanwhile for the UK, Remembrance Sunday (9th November) is expected to be a bright day for most but there will be some heavy showers at times in some western and southern areas.

    By: Matthew Martin