TL;DR

The NOAA Storm Prediction Center (SPC) has issued a Slight Risk for severe thunderstorms across parts of the Midwest today, June 16, 2026. Storms will develop mid-afternoon through tonight with threats including large hail, damaging winds, and a couple of tornadoes. The highest risk spans from the Great Lakes into Iowa, with isolated severe potential also possible across the Gulf Coast, south-central Plains, and northern Plains.

Where is the highest risk today?

The Slight Risk area covers a broad swath of the Midwest and Great Lakes region. According to the SPC Day 1 Convective Outlook issued at 1258 UTC (7:58 AM CDT), the primary threat zone includes:

  • Great Lakes and Midwest: The core severe weather corridor extends from the Great Lakes southeastward, where a low amplitude shortwave trough will amplify and spread across the region today.
  • Iowa and Upper Midwest: A late-night and pre-dawn severe threat will develop across central and eastern Iowa, with large hail the primary concern.
  • South-central Plains: Isolated to widely scattered severe storms are possible across southern Kansas into southwestern Missouri, northern Oklahoma, southern Kansas, and the Texas Panhandle.

Additional isolated severe weather is possible across the Gulf Coast, northern Great Plains, and coastal Mid-Atlantic, though these areas fall outside the categorical Slight Risk.

What's driving today's severe weather?

Multiple weather features are converging to create today's multi-region severe weather setup:

Mid-level dynamics

A shortwave trough will amplify and move east-southeastward over the Great Lakes today. The trough carries a mid-level cold pool with 500 mb temperatures around -18 to -20°C, which will overspread the Midwest this afternoon. This cold air aloft, combined with surface heating, will create instability favorable for thunderstorm development.

Moisture and boundaries

Steady low-level moistening is forecast ahead of a surface low and cold front, and south of a warm front that will shift north and northeastward through the day. While overall moisture content remains modest compared to peak summer values, it will be sufficient to support CAPE values of 1,000-2,000 J/kg across parts of the south-central Plains and higher values in the Midwest.

Wind shear

Sufficient vertical wind shear will support supercell development in multiple regions. The SPC notes that "strong/severe low-topped storms including supercells" are expected in the Great Lakes and Midwest corridor, with the potential for rotating storms capable of producing tornadoes.

When will the storms hit?

Timing varies significantly by region:

Midwest and Great Lakes: Mid-afternoon through early evening

Storms will develop during the mid-afternoon hours and continue through early evening. The SPC outlook states this environment "should become sufficient for a developing broken band of strong/severe low-topped storms including supercells, posing a risk for severe hail/damaging winds and possibly a couple of tornadoes from mid-afternoon through early evening."

Iowa and Upper Midwest: Late tonight into pre-dawn Wednesday

A secondary severe weather window will open late tonight across central and eastern Iowa. The SPC has introduced a categorical Slight Risk for "a steadily increasing late-night/pre-dawn potential for large hail, at least on isolated basis." This threat will develop as a "significantly strengthening southwesterly low-level jet" and elevated mixed layer move into the region, with elevated convection probable early Wednesday.

South-central Plains: Late afternoon and early evening

Isolated to widely scattered thunderstorms may develop during the late afternoon and early evening hours across southern Kansas, southwestern Missouri, northern Oklahoma, and the Texas Panhandle. Boundary-layer moistening ahead of a stalling front will support CAPE of 1,000-2,000 J/kg where mid-level inhibition weakens enough to allow storm development.

Northern Plains: Late afternoon into evening

Scattered thunderstorms with potential for hail and strong to severe wind gusts will develop late afternoon into evening across the northern Great Plains, driven by mid-level forcing for ascent associated with a vigorous shortwave trough.

What are the specific threats?

Large hail

Hail is the primary threat across multiple regions today, particularly in the Midwest and Great Lakes where mid-level cold air will support strong updrafts. The late-night Iowa threat specifically highlights large hail potential as elevated convection develops in an environment with "ample source-region elevated buoyancy."

Damaging winds

Damaging wind gusts are possible with any organized storms, especially if storms form into a broken line or cluster. The northern Plains may see "scattered strong to severe surface gusts" associated with deep boundary-layer mixing ahead of the shortwave trough.

Tornadoes

The SPC explicitly mentions tornado potential in two areas:

  • Midwest and Great Lakes: "Possibly a couple of tornadoes" are possible mid-afternoon through early evening with supercells that develop in the primary corridor.
  • Gulf Coast: Strengthening westerly flow and modest destabilization "may support modestly organizing convection, perhaps transient supercell structures, posing a risk for damaging wind gusts and perhaps a brief tornado or two."

The south-central Plains also have tornado potential if supercells develop in the favorable shear environment.

Yesterday's severe weather

The last 24 hours brought relatively quiet severe weather across the United States, with 0 tornado reports, 1 hail report, and 25 wind reports. Activity was concentrated in South Dakota, where mesonet stations and spotters reported wind gusts ranging from 58 to 69 mph across multiple locations from late afternoon through evening.

The only hail report came from Minnesota, where quarter-size hail fell 6 miles east-northeast of Minneota early this morning. Additional wind reports came from Florida, New Mexico, and Texas, including three power poles snapped along FM 1731 in the Texas Panhandle and shingles blown off a roof in Abernathy.

Looking ahead: Moderate Risk Wednesday

While today's Slight Risk covers a broad area, Wednesday's outlook is more concerning. The SPC Day 2 outlook has been upgraded to a Moderate Risk for parts of Illinois, Indiana, and Ohio, indicating a greater threat of widespread severe weather. This suggests the active severe weather pattern across the Midwest will continue and potentially intensify midweek.

The Day 3 outlook maintains a Slight Risk for parts of Tennessee, Kentucky, and Ohio, indicating the threat will persist into Thursday as the weather system continues moving eastward.

What should you do?

If you're in the Slight Risk area today:

  • Monitor weather conditions throughout the afternoon and evening. Conditions can change rapidly as storms develop.
  • Have multiple ways to receive warnings. Wireless Emergency Alerts for tornado warnings will sound on your phone even if it's on silent, but third-party weather apps are silenced by Do Not Disturb.
  • Know your shelter location. If a tornado warning is issued, move immediately to the lowest floor of a sturdy building, away from windows.
  • Don't wait for sirens. Outdoor warning sirens are designed to alert people outside, not indoors. They may not be audible inside your home.
  • Be especially vigilant tonight. The Iowa severe weather threat will peak during late-night and pre-dawn hours when many people are sleeping. Consider leaving your phone volume on if you're in the threat area.

For those in areas with isolated severe potential (Gulf Coast, northern Plains, coastal Mid-Atlantic), stay weather-aware and be prepared to take action if storms develop in your immediate area.

VORTEX is a free web app at vortexintel.app that monitors severe weather nationwide. Pro ($4.99/month) places phone calls to your phone when a tornado or flash flood warning is issued for a location you care about — calls can ring through Do Not Disturb once you enable Emergency Bypass for the number, unlike most third-party app notifications.