Think It's Too Late To Have a Snowstorm in Southeast Lower Michigan; Think Again!

                   Southeast Lower Michigan Snowstorm of May 9th, 1923  

Not since records have been kept in Southeast Lower Michigan (Detroit as far back as 1870), has the snowstorm of May 9th in 1923 been equaled in season lateness and magnitude.

 

A strong cold front, of Arctic origin, pushed across Southeast Michigan on the afternoon of the 8th, creating scattered thunderstorms. The strength of the front was quite evident in Detroit. The temperature plummeted from a near normal reading of 62 degrees at 100 pm to a winter like one of 34 degrees by 600 pm. Behind the front, the stage was set for some startling weather developments for the month of May...even in Southeast Lower Michigan. Rain mixed with snow fell across the area during the evening of the 8th. Detroit received an estimated inch of snow which melted on the ground before ending by midnight. On the morning of the 9th, a low pressure area developed along the front in northwest Ohio and moved over Lake Erie during the afternoon. The developing low pulled warmer, moist air north from the Ohio Valley and mixed with the unseasonably cold air mass over Southeast Lower Michigan.   As a result, a heavy, wet snow began falling during the forenoon hours and continued through the afternoon.

 

Arguably, one of the most astonishing things (and there were several) about the mid-spring snowstorm was that the bulk of the snow fell during the time of day which is normally considered "the heat of the day" or "afternoon heating" when normal highs of the day are attained. The afternoon temperatures never budged from the lower 30s (31-33) and was accompanied by a stiff northwest wind, averaging 15 to 25 mph. Keep in mind, the normal or average high for May 9th is 67...some 35 degrees warmer! The snow ended by the evening in Detroit and at 800 pm, six inches was reported on the ground. The story was even more fantastic as one traveled west and north of Detroit across Southeast Lower Michigan. Generally, six to nine inches fell west to the Ann Arbor area, northwest through Howell, north across Pontiac and northeast up to Port Huron. Even more incredible, snow depths of around a foot were reported at Flint and Lansing north into the Saginaw Valley. Widespread damage was reported to trees, power lines (many had a two inch circumference of snow hanging on them) and telephone poles, especially in the Saginaw Valley. Even so, economic damage was surprisingly small, especially to spring vegetation. Evidently, the earlier spring weather had been abnormally cold and this led to a late green up. Substantial damage from the cold to vegetation and crops was actually averted due to the insulation affect of the heavy, wet snow. 

 

Many May snow records (amounts and lateness in the season) were shattered and stand firm to this day over Southeast Lower Michigan. By the next morning (10th), much of the snow had melted and by the evening, it was just a memory. The official high in Detroit on the 9th was 39, but that occurred just after midnight, before the storm. The low was 31, which occurred in the afternoon during the storm, giving a mean of 35 for the day and 21 degrees below the normal of 56. Other May record snowfalls in Detroit pale in comparison. In 1912, 1.5 inches fell on May 13th for the second highest amount and the latest snow actually occurred the last day of the month, May 31st, 1910 with a trace. So, the next time you think it's too cold for this late in spring or we can't possibly have a measurable snowfall in late April or May across Southeast Lower Michigan, you might want to THINK about it again (or maybe not). 

 

Making weather fun while we all learn, Bill Deedler -SEMI_WeatherHistorian