TL;DR

The Storm Prediction Center has issued a Slight Risk for severe thunderstorms across the central and southern High Plains Thursday afternoon and evening, with large hail and damaging winds the primary threats. A separate Slight Risk covers southern Virginia into North Carolina, where isolated damaging winds may develop along the cold front. Storms should initiate by mid-afternoon across the higher terrain of central Colorado and the southern High Plains, with supercells possible before eventual clustering this evening.

What's driving today's severe weather?

Thursday's severe weather setup is driven by a mid-level shortwave trough and associated jet translating southeastward across the central Rockies and adjacent High Plains. According to the NOAA Storm Prediction Center (SPC), forcing for ascent ahead of this feature will encourage isolated to scattered thunderstorm development across the higher terrain of central Colorado by mid-afternoon. A weak southern-stream perturbation will also foster scattered convection farther south across the southern High Plains.

The airmass across the central and southern High Plains should gradually destabilize today as modest moisture in a persistent low-level upslope flow regime continues streaming northwestward beneath steepened mid-level lapse rates. Weak to moderate instability is forecast to be in place by mid-afternoon, with sufficient deep-layer shear for a mix of multicells and supercells.

Meanwhile, across the Mid-Atlantic, daytime heating south of a cold front should help steepen low-level lapse rates across parts of southern Virginia into North Carolina by this afternoon.

Where is the highest risk today?

The SPC's Slight Risk encompasses the central and southern High Plains, including parts of Texas and eastern Colorado. A separate Slight Risk covers southern Virginia into North Carolina.

Marginal Risk areas have been expanded to include parts of west into south Texas, where any convection that develops eastward may pose an isolated hail or wind threat this afternoon through tonight. Additional Marginal Risk zones extend across coastal Texas into the lower Mississippi Valley.

Central and Southern High Plains

This is where the most organized severe weather is expected. Initial thunderstorm development should begin across the higher terrain of central Colorado by mid-afternoon, then spread across the southern High Plains through the evening hours.

The SPC notes that "initial development should pose a threat for large hail, before eventual clustering this evening potentially results in a greater threat for severe winds." A tornado or two may also occur given the favorable deep-layer shear environment.

Southern Virginia into North Carolina

While both mid-level flow and lapse rates are expected to remain fairly modest across this area, an isolated threat for damaging winds may exist with loosely organized clusters that can develop along the higher terrain and/or sagging cold front this afternoon.

When will storms develop?

High Plains: Mid-afternoon through evening (roughly 3 PM to 10 PM local time). Initial development favors the higher terrain of central Colorado, with southward expansion across the southern High Plains through the evening.

Virginia/North Carolina: This afternoon, with the threat tied to the southward progression of the cold front and daytime heating.

What hazards to expect

Large hail

The primary threat during the initial phase of storms across the High Plains. Supercells developing in an environment with weak to moderate instability and sufficient deep-layer shear will be capable of producing large hail, potentially in the 1.5 to 2-inch diameter range.

Damaging winds

As storms cluster this evening across the High Plains, the threat should transition toward damaging winds. Across Virginia and North Carolina, isolated damaging winds are the main concern with any loosely organized clusters that develop.

Isolated tornadoes

The SPC mentions that "a tornado or two may also occur" across the High Plains given the favorable shear environment. However, this is not the primary threat today.

Yesterday's severe weather

Wednesday brought widespread severe weather across the Mid-Atlantic and Appalachians, with 117 wind reports and 12 hail reports. No tornadoes were reported.

Wind damage was concentrated across Virginia, Kentucky, and Tennessee, with numerous trees and power lines downed. The most significant hail fell across the region, where reports up to 1.75 inches in diameter (golf ball size) were verified through social media in Clendenin.

Early Thursday morning, a 64 mph wind gust was measured at Port Isabel-Cameron Country Airport in Texas associated with a thunderstorm moving offshore.

Looking ahead to Friday

The SPC Day 2 outlook maintains a Slight Risk across parts of the Central and Southern Plains for Friday, with Oklahoma, Kansas, and Texas in the threat zone. Another round of severe weather appears likely as the upper-level pattern remains favorable for storm development.

Safety reminders for severe thunderstorms

  • Large hail can develop suddenly. If you're outdoors and hear thunder, move indoors immediately. Hail larger than golf ball size can cause serious injury.
  • Damaging winds often arrive with little warning. Straight-line winds from thunderstorms can exceed 80 mph and cause damage similar to weak tornadoes.
  • Don't wait for a warning to take action. If you're in a Slight Risk area, monitor radar and have multiple ways to receive warnings this afternoon and evening.

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.