Fall rainfall varies from 8.79” to 1.0”
With only six days until Christmas, many men I know are just starting their shopping while others are helping put the finishing touches on the holiday feast. It’s not likely that many people will pay much thought to last week’s rainfall now, but weather will likely be a topic of major conversation at some point when farm families gather together. (At least it is at our house!) That’s why today on The Field Position we’re providing you with a little extra “food for thought.”
Most of the Midwest is suffering drought conditions, as Latham Product Manager Mark Grundmeier posted last Thursday. We need moisture. Interestingly enough, not all areas of the state are in such dire straits.
Precipitation totals have been extremely variable this fall, says State Climatologist Harry Hillaker with the Iowa Department of Agriculture & Land Stewardship (IDALS). Soil moisture levels vary from near field capacity in extreme southeast Iowa (where Keokuk has seen 8.79 inches of rain since Nov. 1) to far below the typical early winter levels in the northwest (where total precipitation since Sept. 1 has been only about an inch in some areas centered around Cherokee County).
“The rain event of December 13-14 brought a statewide average of 0.76 inches of precipitation,” says Hillaker. “As expected, the greatest rains fell in the southeast and the least in the northwest.” Only 0.2 to 0.4 inches of rain fell the northwest quarter of Iowa while the Keosauqua and Mount Pleasant areas received 2 to 2.5 inches last week. Fortunately, there is not much frozen soil across Iowa allowing most of this rain to soak into the ground.
Can we make up for a lack of fall rain with snow? Hillaker says snowfall generally does not provide much benefit to soil moisture levels in Iowa for two main reason. First, snowfall on average accounts for less than 10% of our annual precipitation. Second, much of the moisture falls on frozen ground and doesn’t easily make its way into the soil as it melts. Nevertheless, snow cover helps eliminate wind erosion as wet top soil is not easily blown away.