Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0757 PM CDT Sun Aug 30 2026
Valid 310100Z - 311200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
THE NORTHERN PLAINS...
...SUMMARY...
Severe storms capable of damaging wind gusts remain likely across
portions of the northern Plains this evening.
...Northern Plains...
Evening water-vapor imagery showed a strong, negative-tilt mid-level
low and embedded shortwave trough ejecting eastward across southern
SK into eastern MT. Accompanying the low, a prominent mid-level jet
streak (60-70 kt) was quickly moving across the Rockies and into the
Plains. A cold front, attendant to a surface low in southern Canada,
will sweep quickly eastward across the Dakotas tonight.
A well-develop squall line was observed along/ahead of the front
from southern SK/MB to northern SD this evening. Within the line,
numerous strong to severe gusts have been observed thus far. Aided
by the enhanced mid-level flow ahead of the advancing upper trough,
ascent will continue to support the line as it moves eastward this
evening. The air mass downstream in the eastern Dakotas has remained
sheltered much of the day, but is very moist with dewpoints in the
upper 60s to low 70s F. Given the presence of an established cold
pool and sufficient deep-layer shear, especially along the southern
portions of the squall line, the severe threat may continue eastward
this evening across southern ND and SD into the late evening hours,
with a risk for damaging gusts.
Eventually, increasing nocturnal inhibition and the weaker buoyancy
should favor a decreasing severe risk. Convection may transition to
more elevated structures above the more stable PBL with an isolated
risk for occasional damaging gusts and some hail into the overnight
hours across eastern ND and western MN.
...Central Rockies and High Plains...
At the base of the upper low and shortwave, scattered thunderstorms
were ongoing from eastern UT into western/central CO this evening.
Enhanced mid-level flow is supporting organized clusters and some
rotating storms. Hail or severe gusts are possible. Convection
should weaken as it enters the more stable and cooler higher terrain
across central CO. Sporadic strong gusts or small hail remain
possible withe more robust storms in the mountains through tonight.
East of the Divide, high-based showers and thunderstorms should
increase in coverage this evening as a secondary mid-level vorticity
maximum moves out over the Plains. Increasing ascent amid warm
surface temperatures and steep low-level lapse rates (00z DDC
sounding) should support strong downdrafts capable of severe gusts
in the 60-75 mph range. 30-40 kt of deep-layer shear will support
some conglomeration with hi-res model guidance showing a cluster or
weak MCS moving across the High Plains of eastern CO, and western
KS/NE this evening/tonight.
...AZ...
Scattered thunderstorms over the lower deserts should persist
through this evening given very hot surface temperatures and
seasonable monsoon moisture. Moderate buoyancy but weak deep-layer
shear should support multicell storms. Steep low-level lapse rates
could result in a few strong to severe gusts this evening.
..Lyons.. 08/31/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVFS6Q
