March 20, 2013
I slid all the way down the hill,” the woman said. “I just kept praying Lord don’t let me slide into my husband’s truck!”“We had nineteen inches of snow on top of two inches of ice,” the man told me. “When we warmed up a bit, water just ran in a big river across my drive.”
It’s spring: But you wouldn’t know it by looking outside!
It looks and feels like mid-January. Snow piles make it hard to see my milk house. For cities and farms alike it’s hard to figure out where to put all the snow.
This weather comes on top of a year of drought. Feed was short and hay unbelievably high priced – if you could find it.
My heart goes out to the dairy farmers anxiously watching how much winter feed is left and how much snow is on the ground.
And it’s snowing again: another 3-6 inches the beginning of the week and then temperatures slide back into single digits.
It’s been an unusually wet winter. But the recently released US Drought Monitor still has much of western Wisconsin and southeast Minnesota rated at moderate to severe drought. Much of the drought ratings are unchanged despite unusually heavy snow.
I wondered why. I learned from our local National Weather Service about something called concrete frost.
Soil is usually filled with millions of tiny tunnels and holes. This soil “structure” allows water to penetrate the subsoil, recharging aquifers and creating residual moisture. Saturated soil is the filling of these tiny tunnels and holes. Concrete frost happens when this saturated ground becomes solidly frozen.
Concrete frost can have a significant impact on snow melt runoff. Even a little rain or warming can produce flooding as very little water is able to enter the soil. Just like water hitting concrete, the water hits the ground and immediately runs off.
Areas of concrete frost now stretch across south-central Minnesota, west and central Wisconsin and all the way to the Wisconsin-Illinois border.
Frost depth is unusually deep this year- as deep as 43 inches in Bloomer. The topsoil layer is solidly frozen. But underneath the snow and frozen ground lies dry soil.
According to the National Weather Service, as reported in the Winona Daily News, the concrete frost is the result of the thaw in January that was followed by wintery rain. The few inches of snow on the ground were washed away. Temperatures then dropped which froze the saturated soil into a 15 to 30 inch barrier.
That barrier can cause the melting snow to runoff quickly causing rapidly rising rivers and streams.
March 18-22 is National Flood Safety Awareness Week.
The Federal Emergency Management Agency (FEMA) and the National Oceanic and Atmospheric Administration (NOAA) are partnering to improve public awareness of floods.Officials recommend people assess their flood risk. Buy flood insurance if you live in an area prone to flooding. Talk with family members about flood safety. Make sure every family member knows the evacuation plan.
Most of all – do not drive through flooded roads. “Turn around – Don’t Drown” is this year’s slogan officials are using to remind people of the number one cause of the loss of life in a flood.
The summer storms of 2010 brought me a deep respect for Mother Nature. And an appreciation of the professional work of emergency managers, civil engineers, and hydrologists who can predict when and where the flooding will peak.
While we long for sunshine, warm temperatures and green fields, a slow melting season may be best to minimize flooding and to recharge dry subsoil.
At least for the near future, that looks like what’s in store. Not a single night above freezing predicted for the next ten days even though this week the calendar marks the first day of spring.