On Tuesday afternoon, the Storm Prediction Center issued an urgent severe thunderstorm watch covering portions of southwest Illinois, western Kentucky, and eastern Missouri — a stretch of the central U.S. where an unusual storm setup is raising concern.
The culprit: mostly elevated storms, driven by strong instability aloft rather than surface-based dynamics. By early evening, those storms could produce hail up to 2 inches in diameter and isolated wind gusts reaching 70 mph.
What the Watch Covers and When
Severe Thunderstorm Watch 172 was issued by the NWS Storm Prediction Center out of Norman, Oklahoma, at 1:30 PM CDT on Tuesday, April 28, 2026. It remains in effect until 9:00 PM CDT — roughly seven and a half hours during which severe weather conditions are considered favorable.
The watch area runs approximately 60 statute miles east and west of a line from 45 miles northeast of Vichy, Missouri, to 35 miles east-southeast of Poplar Bluff, Missouri. That corridor cuts through southwest Illinois, western Kentucky, and eastern Missouri — a region that doesn’t always find itself at the center of spring severe weather setups.
Watch 172 isn’t operating in isolation. Three other watches — numbers 169, 170, and 171 — remain active concurrently across the broader region, signaling that this is part of a wider outbreak unfolding across the central United States on Tuesday, not a localized event.
The Hazards: Large Hail and Damaging Winds
The primary threat from these storms is hail. The SPC specifically calls out scattered large hail with isolated very large hail events reaching up to 2 inches in diameter — roughly the size of a golf ball. At that size, hail can cause significant damage to vehicles, rooftops, and crops.
Wind is a secondary but still serious concern. Isolated gusts up to 70 mph are possible, strong enough to down trees, snap power lines, and cause structural damage to vulnerable buildings. Aviation interests face a separate set of hazards: hail at the surface and aloft up to 2 inches, extreme turbulence, surface wind gusts to 60 knots, and cumulonimbus tops potentially reaching 50,000 feet. Pilots operating near the watch area should treat these storms with considerable caution.
One additional point: the SPC’s standing reminder holds that severe thunderstorm watches don’t rule out tornadoes. Severe thunderstorms can and occasionally do produce them, even without a tornado watch in place.
Why Elevated Storms Pose a Distinct Challenge
The word “elevated” in the SPC’s summary is doing a lot of work. Most people think of severe thunderstorms as rooted in surface heat — the kind that build on a hot summer afternoon when ground-level air turns unstable. Elevated storms draw their energy from instability higher up in the atmosphere instead, bypassing surface-based dynamics entirely.
That distinction shapes both how these storms behave and how they’re anticipated. Without strong surface-based cues — rising temperatures, obvious boundary layer convergence — development and intensification can happen in ways that feel less predictable from the ground. Standard visual or sensory warning signs may simply be less apparent to people outdoors.
Despite their higher origin, these storms are fully capable of producing significant hazards at the surface. Strong instability aloft is pushing them east-northeastward through the afternoon and early evening, with large hail remaining the most likely hazard. The elevated nature of these storms doesn’t reduce the threat — it changes where that threat originates.
What Residents Should Do Now
The most important thing to understand about a watch is what it isn’t. A severe thunderstorm watch doesn’t mean a severe storm is occurring or has been confirmed in your area — it means conditions are favorable, the atmosphere is primed, and the threat is real. Vigilance, not panic, is the appropriate response.
Residents across the affected parts of Illinois, Kentucky, and Missouri should monitor the NWS for later statements and any warnings issued as storms develop. Warnings carry confirmed or imminent threats and require immediate action.
Practical steps include securing outdoor furniture or objects that could become projectiles in high winds and identifying a safe interior room on the lowest floor of a sturdy building. Make sure weather alert systems — a phone app, NOAA weather radio, or local broadcast — are active and within reach before storms arrive.
As the afternoon progresses toward the 9:00 PM CDT expiration, the storm picture will become clearer. Watch for updates from the SPC and local NWS offices, and pay attention to whether any of the concurrent watches expand, get upgraded, or give way to more targeted warnings as the evening unfolds.