Extreme CAPE Environment Sparks 80 MPH Gusts Along NE/SD Trough — SevereWX

A surface trough cutting through western and central Nebraska into southeast South Dakota is setting the stage for isolated severe thunderstorms this early evening.

Temperatures soaring above 100°F have combined with rich low-level moisture and steep lapse rates, fueling MLCAPE values from around 2000 J/kg in west-central Nebraska to over 4000 J/kg farther north into southeast South Dakota. This explosive instability, paired with veering winds and 30-40 kt effective shear, creates a conditionally favorable setup for organized storms despite weak large-scale lift.

SPC anticipates at least isolated development by early evening near the trough, with the primary threat being straight-line wind gusts of 60-80 mph in the steep low-level lapse rate environment. A supercell or two could also bring isolated large hail up to 1.75 inches. Watch issuance odds stand at 60% to cover these hazards.

Timing remains the wildcard, but the thermodynamic juice is undeniable—stay vigilant across the region from North Platte to Sioux Falls areas.

Preparedness Tip: Monitor radar closely this evening, secure outdoor items, and have a severe weather plan ready. Check SPC updates at spc.noaa.gov.