Severe thunderstorms are expected across parts of the Plains today, with the greatest threat over Nebraska and western Iowa this evening into tonight. Damaging winds, large hail, and a few tornadoes are possible.

Locations:

  • Primary Risk Area: Nebraska and western Iowa
  • Secondary Risk Area: Western Kansas, Oklahoma, and the Texas Panhandle into SW Texas

Threats:

  • Severe Winds: Potential for winds 75 mph or more, especially in Nebraska and western Iowa.
  • Large Hail: Likely with initial supercells.
  • Tornadoes: A few possible, especially with robust supercells into the evening hours.

Timing:

  • Storm Initiation: Expected late afternoon and evening.
  • Peak Intensity: Evening into tonight.

Discussion

  • Northern Plains:
    • Strong daytime heating is occurring across the central and northern Plains, with southerly low-level winds drawing moisture northward into the region.
      • Dewpoints will be in the 50s across ND, SD, NE, and KS this afternoon, promoting the development of thunderstorms ahead of a potent upper trough and associated mid-level speed max.
        • Initial storms will be high-based supercells capable of very large hail and damaging winds, with a tornado or two possible.
          • As evening progresses, storms are expected to grow upscale into a fast-moving QLCS, enhancing the risk of damaging winds across central/eastern NE into western IA.
  • Southern Plains:
    • Multiple rounds of thunderstorms over TX during the past 24 hours have created a complex surface pattern with pockets of low clouds and more stable air, reducing confidence in the exact location of robust thunderstorm development later today.
    • Two areas of concern:
      1. Western OK/northwest TX: Along the dryline.
      2. Central/north TX: Near remnant outflow boundaries.
    • Both areas have very large CAPE values and favorable vertical profiles for supercell storms capable of very large hail, damaging winds, and a tornado or two.