UPDATE: See new post on today’s threat.
UPDATE 5/21 6:00 p.m.
A derecho is looking more and more likely for tomorrow morning. There may be more support for these storms to be severe especially west of Springfield.
Latest model guidance shows a line of mostly non-severe storms sweeping through the Ozarks during the day on Friday. This will have the effect of stabilizing the atmosphere over our area.
However, there still is some disagreement on what happens after this line pushes through especially in areas of extreme southwest Missouri where the atmosphere may recover sufficiently to support more storms.
In the loop below, the “surge of white” is the thunderstorm line reducing the instability in its wake. Note at the end, instability comes back to extreme southwest Missouri.
Note: The SPC put much of the Ozarks in a Slight Risk category for tomorrow.
Today, the idea of a line of storms either progressing right through the Ozarks or perhaps stalling with storm redevelopment looks very plausible.
The instability and wind fields will support all severe weather types including tornadoes.
The SPC has us in a marginal risk area. The area I think is spot on, it remains to be seen what type of coverage and intensity we will encounter.
While the SPC hasn’t quite pulled the trigger on this yet (we’ll see what happens on the early morning update on Wednesday), I think the Ozarks will have to keep an eye out for severe weather on Friday.
Much will hinge on the development of a small disturbance which will cross from Oklahoma and Kansas and into our area during the day on Friday.
Latest model guidance does show an increase in wind speed aloft needed for supercell storms. Additionally, a return of richer Gulf of Mexico dew points should provide for enough unstable air.
There might be support for a daytime line of storms but it’s too early to tell.
CIPS analog guidance supports some severe weather on Friday and Friday night.