Hot and humid conditions continue across Mid-Missouri Monday, and that combination will allow heat indices across the area to soar into the triple digits.
Heat indices between 103 to 108 are expected in Mid-Missouri, and a Heat Advisory is in effect for the entire region until 8:00 p.m. The hottest temperatures will be further west, including areas along Highway 65 and west.
The hot temperatures and high dew points are creating a very unstable atmosphere, but the warmer temperatures at the lower levels are helping to create an inversion, or “cap” just above the surface of the atmosphere.
In order for us to see thunderstorm development this afternoon, we’ll need the daytime heating or forcing from a frontal boundary to break through this cap.
We’re keeping an eye on a weak cold front to our north to provide enough lift for storms to develop later tonight, starting in northern Missouri.
If the cap does indeed break, we could see strong to severe thunderstorms. Much of Mid-Missouri north of I-70 and areas east of Highway 63 are under a slight risk for severe storms for this reason. The primary threats are damaging winds and hail, but there is enough wind shear through the atmosphere that we could see an isolated tornado or two.
There is an increased risk of severe weather further east of St. Louis into central and northern Illinois.