Scattered strong storms with severe hail and wind are likely across the Northern and Central High Plains this afternoon and evening. Isolated large hail is also possible in southwest Texas.

Locations:

  • Slight Risk Area: Northern/Central High Plains and Southwest Texas

Threats:

  • Severe Hail and Wind: Northern/Central High Plains
  • Large Hail: Southwest Texas

Timing:

  • Storm Initiation: Mid to late afternoon
  • Peak Threat: Late afternoon through late evening
  • Tornadoes: Any tornadoes would be confined to mostly ESE Colorado

Discussion:

Northern/Central High Plains

  • Setup: A mid-level shortwave trough over the Northern Rockies will move eastward, with associated lee troughing expected across the Northern/Central High Plains. Modest low-level moistening (dewpoints potentially in the 50s) will occur along and east of the lee trough. Afternoon temperatures will warm well into the 80s beneath steep mid-level lapse rates, resulting in SBCAPE of 1000-2000 J/kg with minimal convective inhibition.
  • Storm Development: High-based thunderstorms are expected to form by mid-afternoon near the lee trough and spread eastward through late evening. Some storms may be maintained into the night due to a strengthening low-level jet and warm advection.
  • Severe Potential: Occasional severe outflow gusts of 60-70 mph and isolated large hail (1-1.5 inches in diameter) will be the main threats, with primarily multicell clusters and some weak supercell structures possible due to weak-moderate deep-layer shear (effective shear generally 25-30 kt).
  • Tornado Risk: The tornado risk across E/SE Colorado is not zero but it certainly isn’t high either. A storm would need some help via mergers or a merging boundary from other cells to spin up enough most likely.

Southern Plains

  • Setup: Widespread convective overturning has occurred across TX over the past 24 hours, with the remnants of a large MCS now weakening just off the lower TX coast. Lingering low-level moisture and steep lapse rates across the Trans-Pecos could support isolated thunderstorm development this afternoon near the Davis Mountains.
  • Storm Development: MLCAPE in excess of 2000 J/kg and sufficiently long hodographs will favor splitting supercells capable of producing isolated large hail, potentially 2 inches in diameter or larger. Marginally severe storm development may occur near the upper TX coast later today with a remnant MCV on the edge of richer low-level moisture.
  • Severe Potential: The southern portion of the central High Plains convection may persist through tonight and grow into a loosely organized MCS from western KS southward into the TX Panhandle and western OK, encountering gradually increasing low-level moisture in a warm advection regime. A few strong gusts and isolated/marginally severe hail may occur with the strongest embedded storms.

Central Appalachians/Mid-Atlantic

  • Setup: A mid-level trough over OH will move eastward to the Mid-Atlantic coast by early tonight. Low-level moisture will be relatively limited in advance of the mid-level trough and a weak surface reflection. However, surface heating and steepening low-level lapse rates will contribute to weak SBCAPE of 250-500 J/kg.
  • Storm Development: Scattered, low-topped thunderstorms will be possible this afternoon across PA/MD/VA, spreading to the coast this evening.
  • Severe Potential: The steep low-level lapse rates will promote gusty outflow winds, but severe/damaging winds appear unlikely given marginal buoyancy and weak low-level flow to limit momentum transfer.