LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0101 AM CDT Sat Aug 22 2026
Valid 221200Z - 231200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE UPPER OHIO VALLEY...
...SUMMARY...
Scattered damaging gusts are likely across the Ohio Valley with more
isolated damaging wind potential extending westward into the Mid
Mississippi Valley and southern Plains this afternoon/evening.
Isolated hail and damaging winds are also possible over the Front
Range, Great Basin and parts of the northern Rockies.
...OH and TN Valleys...
An upper low initially over the western Great Lakes is forecast to
deepen as it moves southeastward today and tonight. A belt of
stronger mid-level flow behind the trough will move into parts of
the Plains and Midwest. A weak surface low and trailing cold front
will move southeastward across the Lakes and into the upper OH
Valley through the day. Ahead of the front, upper 60s to 70s F
surface dewpoints and filtered diurnal heating should allow for
moderate destabilization, sufficient for scattered to numerous
thunderstorms by early afternoon. Despite generally modest to weak
deep-layer shear, steepening of lower/mid-level lapse will support
stronger downdrafts within organized multicell clusters. With time,
some upscale growth into linear segments is also possible and would
also favor a risk for scattered damaging gusts. This appears most
likely across central/eastern OH and KY into western PA/WV.
Farther south, more isolated storm coverage is expected ahead of the
front from the western Carolina Piedmont to the TN Valley. Steep
low-level lapse rates and enhanced low and mid-level northwesterly
flow will still support some risk for isolated damaging gusts.
...Ozarks/Mid MS Valley...
A weak convectively augmented shortwave trough is forecast to move
from southeastern KS and southern MO into northern AR along western
portions of a weak surface front by midday. Ahead of these features,
a very warm and humid air mass will be in place, which should allow
substantial diurnal destabilization and eventual thunderstorm
development. Enhanced northwesterly flow may help organize a few
thunderstorm clusters as they spread eastward from the Ozarks into
the ArkLaTex and mid MS Valley. Damaging wind gusts and some hail
are possible.
...Front Range and adjacent High Plains...
Post-frontal upslope flow, aided by a weak short wave impulse on the
eastern periphery of the upper ridge will support thunderstorm
development along/east of the Laramie mountains through Colorado
Front Range this afternoon. On the fringes of the stronger northwest
flow aloft, deep-layer shear will be marginal for storm
organization. Steep mid-level lapse rates and moderate buoyancy
could support some hail with the stronger updrafts. Isolated
damaging gusts are also possible, especially with any more
persistent thunderstorm clusters.
...Southern Plains...
Very hot surface temperatures (100+ F) are likely across parts of
western North TX into southwestern and central OK this afternoon.
Low-level convergence near a thermally enhanced surface low and weak
front will aid high-based thunderstorm development late afternoon
into the early evening. Weak buoyancy atop the steep low-level lapse
rates and deep mixed layer will favor very strong downdrafts within
the high-based storms. Isolated severe gusts (possibly 65-75 mph
gusts) associated with microbursts are possible as convection is
forecast to move southward through the evening.
...Northern Rockies to the Great Basin....
An upper low along the western periphery of the substantial
mid-level ridge over the Southwest will migrate northward toward the
international border as a belt of stronger mid-level flow
overspreads a plume of monsoon moisture from the Great Basin to the
Northern Rockies. Ascent from the upper wave and heating of the
modestly moist air mass should allow for weak destabilization and
scattered thunderstorm development. Steep lapse rates could support
isolated severe gusts.
Isolated hail is also possible with scattered thunderstorms from
eastern WA into the ID panhandle. Closer to the upper trough and
beneath strong mid-level flow, elongated hodographs may promote
organization with transient supercell structures. Cooler mid-level
temperatures could favor hail production despite modest overall
moisture.
..Lyons/Weinman.. 08/22/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TV73Nz
Windy.com Temps | Gusts | WU KORD KPWK |
CLICK for this month's BIG night sky ... | RADAR FULL MAP SCREEN |
|---|
MOBILE DEVICE? Turn sideways. Weather conditions directly above are near Lakefront. Top tabs refer to O'Hare (official).
Archives for the SPC Convective Outlook are updated daily (approximately) with a live map at the beginning of each article. Follow the link at the end of the article to check for current updates on the NOAA/NWS Storm Prediction Center website. Also, see Archives for Chicago's hourly weather data on CARDINAL NEWS Magazine.
CONVECTIVE | TORNADO | WIND | HAIL
O'Hare International Airport KORD
(Arlington Heights South)
Chicago Executive Airport KPWK
(Arlington Heights North)
Saturday, August 22, 2026
SPC Aug 22, 2026 0600 UTC Day 1 Convective Outlook
SUNRISE AND SUNSET TIMES IN UTC (if you're not logged in to Google)
CHICAGO UTC-6 during CST (Central Standard Time, e.g., winter)
CHICAGO UTC-5 during CDT (Daylight Savings Time, e.g., summer)
CHICAGO UTC-6 during CST (Central Standard Time, e.g., winter)
CHICAGO UTC-5 during CDT (Daylight Savings Time, e.g., summer)




















