After almost having a “sunny & 75” forecast yesterday, our attention turns to the potential for thunderstorms this evening. The Storm Prediction Center (SPC) in Norman, OK has placed the Western half of the Stateline is under a Slight Risk, while the other is under a Marginal Risk. Now, don’t pay attention to the category. Just know that there is the potential for severe weather throughout this afternoon and evening.
There are two key features that we need to keep an eye on for today’s severe weather potential. The first is the stationary front in central Illinois, and the second is a low pressure system out in the Midwest. Models continue to show this stationary boundary lifting northward as a warm front. If this does occur, the viewing area will be placed in the warm sector of the low pressure system. This is where a large amount of moisture and warmer air is brought up from the south. This will provide a potent environment for severe storms to form. With that said, if the warm front fails to lift north and stays to our south, than that drops our severe weather chances drastically.
There’s one other factor into whether we will encounter severe storms this evening. It’s something meteorologists call “the cap”. Normally, temperatures decrease the further up you go in the atmosphere. But sometimes, there will be layer of relatively warm air aloft, usually several thousand feet above the surface. This acts as a blocker and delays the development of thunderstorms.
Thunderstorms rising into this warm layer become much cooler than the surrounding air, which inhibits their ability to rise and fully mature.If thunderstorms can break “the cap” this afternoon, the severe weather potential for our area will increase.
The time frame in which we have the best chance to see severe thunderstorms will be from 4 PM to 11 PM. Storms will initially develope out to our west. They will then move in during the evening commute, so make sure you take your time heading home this evening. Most likely will see gusty winds and large hail, but a tornado or two cannot be ruled out!
And with severe weather in mind, here are a few severe weather safety tips. Always have multiple ways to receive watches and warnings issued by the National Weather Service. That could be with a weather radio, your local meteorologist, or on your cell phone. Then, make sure that you have a safe place and a severe weather kit ready to go!