SPC AC 151249

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0749 AM CDT Sat Aug 15 2026

   Valid 151300Z - 161200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
   THE CENTRAL HIGH PLAINS AS WELL AS THE MIDDLE OHIO VALLEY...

   ...SUMMARY...
   Thunderstorms with severe wind gusts and isolated large hail will be
   possible from late afternoon into the evening across the central
   High Plains. Severe wind gusts will also be possible this afternoon
   into the early evening across parts of the Ohio Valley.

   ...Central High Plains...
   Relatively moist southwesterly flow aloft coupled with strong
   daytime heating and lift both from orographic effects and a weak
   vorticity maximum will support another day of thunderstorms across
   the central Rockies. These thunderstorms should gradually move off
   the higher terrain into the central High Plains, where a moderately
   buoyant airmass will be in place. Around 30 to 35 kt of effective
   bulk shear is expected over the region as well, which is strong
   enough to support a mixed mode with supercells and multicell line
   segments. Isolated large hail is possible with any supercells, while
   severe wind gusts will be possible with both supercells and line
   segments. The severe threat should persist into the early to mid
   evening as this complex of storms moves eastward through the central
   High Plains.

   ...Central OH Valley...
   An expansive, slow-moving MCS, characterized by widespread showers
   and sub-severe thunderstorms, is centered over central IL this
   morning. This MCS has been supported overnight by a southwesterly
   low-level jet that extends from the southern High Plains into the
   Mid MS Valley. This low-level jet is forecast to wane throughout the
   morning, with a subsequent decrease in coverage and intensity of the
   showers and thunderstorms within the MCS. Even so, the vorticity
   maximum associated with this system will gradually drift eastward,
   likely supporting renewed thunderstorm development across the
   middle/upper OH Valley as it interacts with a diurnally
   destabilizing airmass. Lapse rates will be poor, but dewpoints in
   the 70s will still support moderate buoyancy, particularly in areas
   where cloud cover does not overly inhibit diurnal heating. This
   currently appears most likely from far southeast IN into southern OH
   and northern KY. Strong updrafts and high precipitable water will
   support the potential for wet microbursts capable of producing
   damaging gusts.  

   ...Central Appalachians into the Carolinas and GA...
   A very moist airmass, characterized by dewpoints in the low to mid
   70s, is in place from the GA and Carolinas into the central
   Appalachians. Strong heating is forecast to destabilize this airmass
   by the early afternoon, resulting in a large reservoir of moderate
   buoyancy. Thunderstorm development is anticipated within this
   destabilized airmass across the higher terrain of the central
   Appalachians as well as any area of low-level convergence across the
   remainder of the region. Vertical shear will be weak, and limited
   storm organization is anticipated. Even so, the moderate buoyancy
   could still support updrafts/downdrafts strong enough to produce
   occasional damaging gusts.

   ...Central Plains/Mid MO Valley into the Mid MS Valley...
   Elevated thunderstorms are expected again this evening through
   tonight, initiated by both an approaching cold front and warm-air
   advection. Ample low-level moisture and moderate buoyancy will be in
   place, but vertical shear will be marginal. Isolated strong to
   severe storms are expected, but a predominantly elevated and
   clustered storm mode should limit the overall severe potential.

   ..Mosier/Dean.. 08/15/2026

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