Bottom line
The NOAA Storm Prediction Center (SPC) has issued a Slight Risk for severe thunderstorms across two regions today: the southern Appalachians into the Savannah River Valley, where damaging wind gusts are the primary threat this afternoon and early evening, and western and central Montana, where large hail is expected this afternoon and evening. Yesterday brought 337 wind reports and 31 hail reports across 19 states, continuing a multi-day severe weather pattern. Additional Marginal Risk areas span the central Plains, northern Plains, Ozark Plateau, and Gulf Coast states.
Where is the highest risk today?
Two Slight Risk areas anchor today's outlook:
Southern Appalachians through the Savannah River Valley: Damaging wind gusts are the primary concern, with isolated large hail possible.
Western and central Montana: Large to very large hail is expected across this region as supercells develop over higher terrain and track northeast into lower elevations.
Surrounding these Slight Risk zones, Marginal Risk areas include the Ozark Plateau, Gulf Coast states, eastern Dakotas, western Minnesota, and portions of the central and northern High Plains.
What's driving today's severe weather?
Multiple weather features are converging to fuel thunderstorm activity across the country:
Southeast moisture and instability: Low to mid-70s dewpoints blanket the Southeast this morning. Strong heating will push afternoon temperatures into the low to mid-90s, destabilizing the atmosphere and generating moderate to strong buoyancy. The SPC forecasts mixed-layer convective available potential energy (MLCAPE) around 2,000–2,500 J/kg during the late afternoon — ample fuel for thunderstorms.
A subtle shortwave trough moving through northwesterly flow aloft will interact with this destabilized air mass to trigger storm development. Vertical wind shear will generally be weak, limiting organized supercells and favoring outflow-dominant multicellular storms or line segments. However, steep low-level lapse rates and abundant moisture create favorable conditions for damaging wet microbursts.
Montana's supercell environment: A vigorous shortwave trough is pivoting through the base of a Pacific Northwest upper low, spreading increasing height falls and strengthening mid- and upper-level flow across the northern Rockies. Deep-layer vertical wind shear of 40 to 50 knots will support supercell development over Montana's higher terrain this afternoon.
Greater buoyancy is expected across central Montana, though low-level stability may persist and limit severe wind and tornado potential. Large hail remains the primary threat as storms mature and move northeast.
Plains convection: A linear mesoscale convective system (MCS) continues pushing eastward across the central Plains this morning. A vorticity maximum has developed within the northern portion of this line, tracking northeastward and triggering new development downstream across south-central and southeast South Dakota and adjacent northeast Nebraska.
When will the storms hit?
Southeast: Thunderstorm development is anticipated during the late afternoon as daytime heating maximizes instability. The window for damaging winds extends through early evening, roughly 4 PM to 9 PM local time.
Montana: Storms will develop over higher terrain this afternoon before progressing northeastward toward lower elevations. The severe hail threat will be greatest from mid-afternoon through the evening hours.
Central Plains and Ozark Plateau: Ongoing MCS activity this morning will interact with a moist, diurnally destabilizing air mass through early afternoon. Isolated hail and damaging gusts are possible, particularly along or immediately north of surface boundaries extending through the middle and lower Missouri Valley.
Northern High Plains: Isolated to widely scattered thunderstorms may develop across southeast Wyoming and northeast Colorado during the early evening as a low-amplitude shortwave trough approaches. High-based, outflow-dominant storms will pose a risk for isolated strong to severe wind gusts.
Yesterday's severe weather recap
Saturday brought widespread severe weather across 19 states, with 337 wind reports dominating the day's activity. The Southeast bore the brunt of the wind threat, with numerous trees downed across Virginia, West Virginia, North Carolina, Tennessee, and Kentucky.
Virginia saw significant tree damage and power outages, particularly in the coalfields region between Clinchco and Davenport, where over 1,000 customers lost power.
The central Plains also saw active severe weather, with 31 hail reports concentrated in Nebraska, North Dakota, South Dakota, and Colorado. Alliance, Nebraska, recorded multiple reports of 2- to 2.5-inch hail, with trained spotters documenting accumulating hail along Highway 385.
The Carolinas experienced both wind and hail, with golf ball-sized hail reported in multiple North Carolina communities including Macclesfield, Clayton, and Fort Barnwell.
What to expect in each risk area
Slight Risk: Southern Appalachians and Savannah River Valley
- Primary hazard: Damaging wind gusts
- Secondary hazard: Isolated large hail
- Storm mode: Multicellular clusters and line segments
- Timing: Late afternoon through early evening
The SPC notes that even though vertical shear will be weak, "steep low-level lapse rates and abundant moisture will promote the potential for damaging wind gusts with any longer-lived multi-cells or line segments." Updraft interactions could also produce isolated hail.
Slight Risk: Western and Central Montana
- Primary hazard: Large to very large hail
- Storm mode: Supercells
- Timing: Afternoon through evening
Deep-layer shear of 40 to 50 knots will support supercell development. The SPC has introduced a conditional significant hail area, noting that if storms can overcome lingering convective inhibition and move into the more moist and buoyant air mass north of the surface low, "thermodynamic profiles are favorable for large to very large hail."
Marginal Risk: Ozark Plateau and Gulf Coast
A corridor of enhanced low-level moisture extends from the Southeast through Arkansas and Missouri. Daytime heating will support pulse-type thunderstorms capable of locally damaging wet microbursts during the afternoon and early evening. Weak forcing and limited vertical shear should prevent widespread organization.
Marginal Risk: Eastern Dakotas, Western Minnesota, Lower Missouri Valley
The ongoing MCS and associated vorticity maximum will interact with a moist air mass downstream, with dewpoints in the low 70s from eastern South Dakota through western Iowa and northern Missouri. Occasionally strong updrafts could produce isolated hail and damaging gusts, though weak mid-level flow should limit storm organization.
Safety guidance for today's threats
Damaging wind preparation: Secure loose outdoor objects, particularly in the Southeast Slight Risk zone. If you're outdoors when storms approach, move to a sturdy building. Avoid parking under trees or near structures that could be damaged by falling limbs.
Large hail safety: If you're in Montana's Slight Risk area, move vehicles under cover if possible. Hail larger than 2 inches can shatter windshields and cause significant vehicle damage. If caught driving in large hail, pull over safely, turn away from windows, and cover yourself with a blanket or jacket if available.
Nighttime severe weather: While today's primary threats are during daylight hours, storms may persist into the evening across some areas. Third-party weather apps are silenced by Do Not Disturb, though Wireless Emergency Alerts for tornado warnings still break through on most phones. If severe weather is forecast for your area tonight, keep your phone charged and within reach.
Tomorrow's outlook
The SPC Day 2 outlook shows a Marginal Risk for portions of the central Plains, northern Plains, and Midwest on Monday. The severe weather pattern is expected to continue at lower intensity as the upper-level pattern evolves.
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.