TL;DR
The Storm Prediction Center has issued a Slight Risk for severe thunderstorms today centered over Arkansas and extending from northeast Texas into western Tennessee. Widely scattered supercells are possible this afternoon through tonight, capable of large hail up to 2 inches or larger, damaging winds, and a few tornadoes—including the potential for a strong tornado. More isolated severe storms are also possible across parts of the Northeast and Great Lakes.
Where is the highest risk today?
The Slight Risk area covers much of Arkansas, extending from northeast Texas eastward into western Tennessee. This includes major metro areas such as Little Rock, Fort Smith, Fayetteville, Jonesboro, and Memphis. The Storm Prediction Center notes that the strongest storms will be centered over Arkansas, where the kinematic environment will be most favorable for sustained supercells.
According to the SPC's Day 1 Convective Outlook, "the kinematic environment should be very supportive of supercells this afternoon/evening, with strong upper flow resulting in bulk shear around 60 kt."
The threat extends beyond the Slight Risk area as well. Isolated strong to severe storms are possible across parts of the Lower Great Lakes into northern New England, where a cold front will progress eastward through the day.
What's driving today's severe weather?
The setup across the Mid-South involves several key ingredients coming together this afternoon. A surface low is positioned over western Oklahoma, with a cold front extending east-northeastward through far northeast Oklahoma and southern Missouri. An outflow boundary from overnight storms stretches from north of Little Rock northwestward between Fort Smith and Fayetteville into northeast Oklahoma.
These boundaries—particularly the cold front and outflow boundary—will serve as focal points for storm development as the atmosphere destabilizes through the afternoon.
The warm sector across Arkansas and surrounding areas will see afternoon temperatures climb into the low 80s with dewpoints in the mid 60s. Combined with steep mid-level lapse rates, this will generate moderate buoyancy with MLCAPE (a measure of atmospheric instability) around 1,500 to 2,000 J/kg.
However, there's notable uncertainty in the forecast. The SPC notes that "some weak capping may prevail as well, particularly if the current cloudiness persists," and that "confidence in the placement of such a corridor is currently low, precluding the introduction of any higher probabilities." In other words, storms should be discrete and widely scattered rather than widespread, but exactly where they form depends on how the outflow boundary evolves and whether cloud cover breaks.
When will storms develop?
Storm initiation is expected this afternoon as heating destabilizes the airmass and boundaries sharpen. The peak severe threat will run from late afternoon through tonight across the Mid-South.
Any storms that do mature are expected to be severe. The SPC emphasizes that "any storms that do mature should be severe and capable of all hazards."
What hazards are expected?
Large hail
Large to very large hail—defined as 2 inches or greater—is possible early in each storm's convective cycle. The combination of strong instability and favorable wind shear will support rotating updrafts capable of lofting hailstones to significant size.
Yesterday's severe weather across Illinois, Iowa, Kansas, Michigan, and Missouri produced 26 hail reports. Today's environment is similar, with the potential for even larger hail in the strongest supercells.
Tornadoes
Tornadoes are possible, particularly from central Arkansas into western Tennessee where low- and mid-level wind flow will be strongest. The SPC notes that "a strong tornado is possible with a sustained discrete supercell."
The tornado threat is most pronounced in areas where supercells can remain discrete and tap into the favorable wind shear environment. Bulk shear values around 60 knots will support rotating storms, and any supercell that can sustain itself for an extended period will carry an elevated tornado risk.
Damaging winds
As storms evolve through the evening, they may grow upscale into clusters or line segments. At that point, damaging winds would become the primary severe risk. The SPC states that "storms may eventually grow upscale into clusters, at which point damaging winds would become the primary severe risk."
Wind gusts of 60 mph or higher are possible with the strongest storms or any bowing segments that develop.
What about the Northeast and Great Lakes?
A separate area of isolated severe storms is possible from the Lower Great Lakes into northern New England today. A surface low over southeast Lower Michigan will progress northeastward along the St. Lawrence Valley as a cold front shifts eastward.
Modest low-level moisture—dewpoints in the low 50s reaching as far north as Maine—combined with afternoon temperatures in the 70s will support modest buoyancy. Thunderstorms are expected along and ahead of the cold front as it moves into this destabilized airmass.
Strong deep-layer vertical wind shear will be in place, but the flow will be largely parallel to the boundary. This favors a bowing linear mode rather than discrete supercells. Damaging gusts will be the primary threat with the strongest storms, though isolated hail is also possible. The tornado risk is low due to the predominantly linear storm mode, though the SPC notes "a low-probability threat still exists, particularly if a pocket of strong buoyancy can develop across Upstate NY."
What should you do?
If you're in the Slight Risk area across Arkansas, northeast Texas, or western Tennessee, monitor the weather closely this afternoon and evening. Have multiple ways to receive warnings—NOAA Weather Radio, a smartphone weather app, and local news.
If a severe thunderstorm or tornado warning is issued for your location, take action immediately. Move to the lowest floor of a sturdy building, away from windows. If a tornado warning is issued at night, don't rely solely on outdoor sirens—they're designed to alert people outdoors, not inside homes.
Third-party weather apps are silenced by Do Not Disturb, though Wireless Emergency Alerts for tornado warnings still break through on most phones. For an additional layer of protection, VORTEX Pro places phone calls when a tornado or flash flood warning is issued for your saved location—calls bypass Do Not Disturb entirely, ensuring you're alerted even if your phone is silenced overnight.
What's the outlook for tomorrow?
The SPC Day 2 outlook maintains a Slight Risk for portions of Texas, Mississippi, Tennessee, Ohio, and the Southeast on Wednesday, May 6. The severe weather threat will shift eastward as the system progresses. Day 3 shows a Marginal Risk for South Carolina and portions of the Southeast and Gulf Coast on Thursday, May 7.
Stay weather-aware, and check back tomorrow for an updated outlook.
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.