The latest snowstorm to affect Kentucky brought the heaviest snow amounts to portions of Kansas and Oklahoma early Wednesday morning. A fresh snowpack over northern Oklahoma, light winds, and clear skies brought some extremely cold temperatures early Thursday morning. The image below is a satellite picture in infrared. Note the yellowish-orange colors over northern Oklahoma and portions of Kansas. Since infrared images indirectly show heat...these colors show temperatures near -20F! As shown, some Mesonet sites in Oklahoma measured early morning lows of -25F to as low as -31F.
For such extremely cold temperatures to occur so far south, conditions have to be just perfect. Aside from a deep fresh snowcover, winds have to be calm. The image below shows that a large area of high pressure was centered right over eastern Oklahoma, ensuring that conditions were just right for strong radiational cooling.
This image below shows an infrared satellite picture of Kentucky. Clear skies were present over the Commonwealth around 7 am EST, when this picture was taken. This image shows the coldest temperatures over southern Kentucky around the Land Between the Lakes...stretching eastward along the Tennessee border towards Lake Cumberland. Indeed, temperatures from some Mesonet sites early Thursday ranged from 0 to -7 degrees.
This last image is a visible satellite image taken around 10 am EST Thursday morning. It shows an extensive snowpack across Kentucky, a lack of snow across southern Indiana, and snow across the deep south...including Arkansas and even northeast Louisiana!
The snowpack seen above had a great influence on morning low temperatures Thursday morning. Lows reached below zero in the areas that received the most new snowfall...whereas points along and north of the Interstate 64 corridor stayed closer to around 10 degrees. Some low clouds lingered over the Lake Cumberland region just until daybreak...helping to keep their temperatures up.