A Slight Risk of severe thunderstorms exists over parts of the Central and Southern Plains today and tonight. The primary threats are large hail, damaging wind gusts, and a few tornadoes.

Location

  • Central and Southern Plains, including portions of:
    • Oklahoma
    • Kansas
    • Texas

Threats

  • Large hail
  • Damaging wind gusts
  • A few tornadoes (highest risk during the late afternoon and early evening)

Timing

  • This afternoon through tonight

Discussion

  • Weather Systems
    • A deep upper-level trough moving across the West will drive storm development across the Plains states.
    • A surface low over the High Plains and a dryline will act as focal points for storm development.
  • Storm Evolution
    • Isolated supercells are likely near the dryline this afternoon, posing the main threat of large hail, gusty winds, and potentially tornadoes.
    • Tonight, additional storms could form as the dryline interacts with an approaching Pacific cold front. While these storms can still produce severe risks, they may weaken somewhat overnight as the atmosphere stabilizes.
  • Uncertainties
    • Localized areas of heating and moisture will be critical factors in determining where the strongest storms occur.
50s dewpoints are in place and a strong fetch of 50s to even 60s dewpoints exist just south of the target region of Western Oklahoma today.
Because of that moisture, weak instability will take shape along a sharpening dryline across Western Oklahoma. The instability axis today will be rather narrow, but storms will be moving NE, with at least 2-3 hours of time before running into air with no punch to it.
The jet stream will be nosing into the region by mid-late afternoon. This lift is going to result in storms.
In what I think is a significant development, the HRRR now shows the entire dryline lighting up across Western Oklahoma. The HRRR is notorious for getting a setup right but for the wrong reasons — as it typically delays dryline initiation a little too long. Here it is firing storms 3-5 p.m. and I think the window for first initiation is probably closer to 2-4 p.m.
Discrete supercells are the favored storm mode today given shear profiles, and expect these storms to form and move across the risk area today with the threat of large hail and tornadoes.
Well after dark, storms will form into a line and move east with damaging winds and a tornado the main threats, though the tornado risk becomes very low after dark.
An environmental analysis shows upper 50 dewpoints with effective SRH values of over 300 m2/s2 along with low LCLs. There will be some capping to deal with today by storms, but strong mesocyclones should be well ventilated, which will result in highly visible tornadoes if they do occur today. This is a pretty idealized cool season tornado sounding in many ways, the key I think is how wide that instability axis is going to be as storms will need a bit of time to get fully organized.