As Mid-Missouri prepares for the first snowfall of the season, many will notice that accumulation will be hard to come by initially Thursday evening. Although winter came in with a bang and temperatures are struggling to climb out of the 30s, the ground temperatures are lagging behind.
We are still technically in fall and although temperatures have been on the cool side, ground temperatures are still in the 40s. With the warmer ground temperatures the snow that falls this evening will begin to melt, except on very grassy surfaces.
Accumulation of snow on grassy surfaces is easier to accomplish than other surfaces out in the elements for several reasons, despite the warm ground temperatures we’ll see. Although it will prevent any significant accumulation across the region, the warm ground translates to few impacts on roadways as Friday morning approaches.
The reason this occurs has to do with the relationship between a road’s surface and the ground temperatures. A road sits directly on top of the ground and/or Earth’s surface. Since it takes time for the soil temperatures to adjust to colder air temperatures, the warm ground will continue to keep roads above freezing. This is true for all roads except bridges and overpasses, which will freeze before roads because of the cold air that funnels on both the top and bottom portion of the bridge. Grassy surfaces though are more exposed to colder air, which is why we typically see accumulation on those surfaces first.
In addition to the soil temperatures, roads take longer to cool off because of the amount of heat they absorb through the day. And while temperatures are expected to drop below freezing into the night, the road temperatures will lag and will likely only cause a few slick spots by the AM commute for the roads less traveled.
Because of these items mentioned above, any snow we see will be very limited in accumulation. Winter came quickly this year, so it will only be a matter of time until the soil temperatures drop with it.
Stay with ABC 17 Stormtrack Weather as we continue to monitor the coming changes and follow us on Twitter @ABC17Stormtrack.