DAY 1 SLIGHT SEVERE WEATHER RISK FROM CENTRAL MT SOUTHWARD INTO NORTHERN UT…MARGINAL RISK OVER PORTIONS OF WV, PA, NY AND THE TX PANHANDLE… FORECAST SYNOPSIS…ISSUED MAY 13, 2026…12:20 P.M. EDT – Image for illustrative purposes only (Image credits: Pexels)
The Storm Prediction Center placed a slight risk of severe thunderstorms across central Montana southward into northern Utah for the afternoon and evening of May 13. A marginal risk extended over parts of West Virginia, Pennsylvania, New York, and the Texas Panhandle. Forecasters highlighted the potential for damaging wind gusts as the primary concern in the northern High Plains and Great Basin, with isolated hail possible in a few locations.
Why the Northern Plains Drew the Higher Risk
Low-level moisture remained limited ahead of an approaching system, yet strong daytime heating created pockets of instability from northern Utah into eastern Idaho, western Wyoming, and central Montana. Those conditions produced inverted-v soundings that supported fast-moving showers and occasional thunderstorms. Computer models showed the storms could generate high-based updrafts capable of producing severe wind gusts as they raced across the region.
The slight risk area carried a 15 percent hatched contour for damaging winds, indicating the greatest concentration of that threat. In contrast, tornado probabilities stayed below 2 percent across the outlined zones, with any twisters expected to remain weak if they formed at all.
Eastern and Southern Areas Under Marginal Watch
Cloud cover initially limited heating across the upper Ohio Valley, but forecasters anticipated some clearing that would allow low-level moisture to fuel scattered storms along a frontal boundary. The environment supported enough instability for a few cells to produce damaging winds or small hail, mainly between 2 p.m. and 8 p.m. local time.
Farther south, a dryline set up across the Texas Panhandle where temperatures climbed into the 90s. Any storm that managed to develop there faced modest instability, yet the conditional threat of strong winds and large hail kept the marginal risk in place for that zone as well.
Key Parameters Point to Wind as Main Hazard
Analysis of multiple high-resolution models showed surface-based CAPE values between 500 and 1,500 J/kg across the slight risk area, with mixed-layer CAPE in the 500-750 J/kg range. Storm-relative helicity remained modest, while deep-layer shear reached 30-50 knots. Those ingredients favored organized cells with strong outflow winds rather than widespread rotation.
Dew points ranged from the low 30s in Montana to the mid-50s farther east, limiting overall moisture but still allowing enough energy for robust updrafts. The significant tornado parameter stayed near zero in the northern zones and only reached 0.4-1.0 in the eastern marginal area, reinforcing the low tornado threat.
What Residents Should Monitor
Storms were expected to peak from mid-afternoon through early evening before weakening after sunset. Anyone in the outlined areas should stay alert for rapidly changing conditions and follow updates from local National Weather Service offices. The next official outlook revision was scheduled for 12:30 p.m. Eastern time on May 13.
Forecasters stressed that even isolated severe storms can produce dangerous winds capable of downing trees and damaging structures. Preparation remains the best defense when indices point to fast-moving cells with limited moisture.
