Multi-Day Storm Chasing Op Begins Today, Plains-Midwest

Today kicks off a multi-day stretch of potentially fruitful storm observation opportunities across the Plains and Midwest. The sequence is a little funky with the risk area largely sandwiched between a weak sub-tropical jet stream sending impulses from the Texas/Mexico border into the Midwest, and a stronger polar jet and deepening trough over the western U.S. with a ridge centered over the Gulf of Mexico and southeast U.S.

The Gulf is wide open with tons of instability and there is flow and lift to be had, but you're also battling a significant cap and you're also kind of lacking stronger flow aloft and minimal/non-existent height rises.

The result is less of a significant period of dryline supercells, and more of 4-5 day opportunity to find pockets of supercell and tornado potential across a broad region. I'd probably be hedging further north most days, trying to get closer to the stronger flow associated with the polar jet and some added lift from the surface low/warm front/cold front. The dryline may struggle for much of this period.

We get started rather gently today. Much of the day today will be quiet with a strong cap keeping a lid on thunderstorm activity. By late evening, a few storms should begin to develop from eastern Nebraska into western and northern Iowa. There may be a 1-2 hour window for a discrete supercell or two with an initial risk of a tornado or some big hail, especially from Omaha to Mason City between 6-9 PM CT. The low-level jet is pretty weak early on, so any tornado potential may not be maximized until closer to sunset, 8-9 PM.

After 9 PM, I'd expect a pretty quick transition toward outflow dominance with a potentially significant cold pool developing as the gust front quickly surges east-southeast. This should signal a pivot toward a decrease in tornado and hail potential, and an increase in 70+ mph wind gusts potential across central and eastern Iowa, perhaps into far southwest Wisconsin, northwest Illinois, and northern Missouri.

I'm not out today, but if I was I'd probably park myself somewhere on Interstate 80 in the Stuart, Iowa area hoping for an opportunity for a late-evening supercell somewhere in that corridor from Omaha to Des Moines with a tornado and hail risk. The I-80 corridor from Des Moines to the Quad Cities may see a few significant wind gusts 70-80 mph from 9 PM - 12 AM Friday night.