Supercells Eye 3-Inch Hail in Wyoming; Wind Clusters Charge Appalachians — SevereWX

Supercells Eye 3-Inch Hail in Wyoming; Wind Clusters Charge Appalachians

Urgent severe weather brewing on both U.S. flanks today. The Storm Prediction Center (SPC) has issued two Mesoscale Discussions (MCDs) signaling high odds—80% each—for severe thunderstorm watches. An MCD is the SPC's early alert to spot rapidly evolving storm threats on a local scale, often the first heads-up before a watch means "severe storms are likely—get ready."

Leading the charge: High Plains supercell explosion. Across southeast Wyoming and nearby Nebraska, northeast Colorado, western South Dakota, and eastern Montana, thunderstorms are firing along the Laramie and Big Horn mountain slopes. Afternoon heating is eroding any lingering storm-killer cap, with temps climbing to the upper 70s fueling deep cumulus towers. Expect these to spin up into supercells by late afternoon, packing 40-50 knot shear for rotating beasts. The bullseye for very large hail up to 2.5-3 inches, damaging winds, and isolated brief tornadoes hits southeast Wyoming into northeast Colorado and western Nebraska, where juicier low-level moisture supercharges updrafts.

Meanwhile, East Coast wind machines rev up. From central Appalachians stretching into the Mid-Atlantic—think West Virginia's ridges, Virginia, Maryland, Delaware, DC, southeast Pennsylvania, southern New Jersey, and bits of North Carolina, Tennessee, and Kentucky—afternoon storms over mountains are bulking up. Strong heating under clear skies downstream, plus rich Gulf moisture pushing north, is cranking instability. Steep low-level lapse rates and 1.75-inch precipitable water promise scattered 60+ mph damaging wind gusts, isolated hail, and a spin-up tornado or two. Greatest odds for nasty clusters or bowing segments track from northern Virginia/Maryland northeast toward southeast Pennsylvania and New Jersey, riding peak mid-level winds.

Watches could drop within the hour for both zones, valid into early evening. Stay vigilant—radar and warnings will ramp up fast.

Prep now: Charge devices, ID your safe spot (interior room, away from windows), keep NOAA Weather Radio handy, and have helmets ready for hail. Check SevereWX.net for live updates. Stay safe out there!