Road Postings Sure Sign of Spring
For me the first sign of spring is when the Minnesota Department of Transportation puts on the spring truck load restrictions. By the way they go into affect this year on Friday March 6, 2020 at 12:01 am. The start of the spring road restrictions is determined by the weather. The Minnesota Department of Transportation monitors the frost depth under the roads and then the temperature to track when the frost begins coming out of the soil. When the frost melts in the spring heavy truck loads can cause a lot of damage to roads!
The frost depth at the Southern Research and Outreach Center at Waseca on February 24, 2020 was 14 inches with a snow depth of 7 inches. The frost depth on March 2, 2020 was 13 inches and there were 4 inches of snow on the ground. I am sure the frost was deeper under our roads because the snow is plowed off. A few inches of snow is a very good insulator that prevents the frost from moving deeper into the soil during very cold temperatures.
I remember road postings going on anytime between the middle of February to about the middle of March. Normally it is in early March. So maybe you could assume we will have a normal spring according to the road postings. However, With the frost in the field only at 13 inches and 4 inches of snow to melt I am optimistic we are on track for an early spring? I remember some years in early March when we had a frost depth of 4 to 5 feet and 24 inches of snow on the ground.
However, it is now all about the temperature and snowfall in March. Typically in March we receive a lot of wet heavy snow. Lets hope it is slightly warmer and much drier than normal and bring on Plant 2020!