LIVE MAP (ABOVE) ... SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1129 AM CDT Sat Aug 29 2026
Valid 291630Z - 301200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN
NEVADA ACROSS NORTHERN UTAH INTO FAR SOUTHWEST WYOMING...
...SUMMARY...
Widely scattered strong to severe storms are expected across parts
of the northern Great Basin, northern/central Rockies, and northern
Plains. Severe wind gusts are the main threat.
...Great Basin through the central Rockies...
Enhanced mid-level southwesterly flow aloft exists between the upper
ridging centered over the southern High Plains and a shortwave
trough moving through the Pacific Northwest. 12Z SLC sounding
sampled this enhanced flow well, reporting a belt of 50-55 kt wind
around 600 to 500 mb. This sounding also sampled the increased
mid-level moisture within this belt of stronger flow, resulting
precipitable water over 1.1".
Modest heating of this airmass is expected to foster moderate
buoyancy, although the widespread cloudiness could keep the airmass
from fully destabilizing. Most RAP soundings across the region
maintain lingering convective inhibition from UT into southern WY.
Even so, the combination of modest buoyancy, mid-level moisture, and
ascent attendant to a low-amplitude shortwave trough progressing
through the region will support scattered to numerous thunderstorms
from eastern NV across UT into northwest CO/southern WY. Some
isolated hail is possible with the strongest cores (which could
briefly acquire supercellular characteristics), but the primary
severe risk is strong to severe wind gusts. Highest severe coverage
is still expected from east-central NV into northern UT where the
greatest afternoon buoyancy is forecast.
...Northeast CO/eastern WY/NE Panhandle into the western/central
Dakotas...
High-based showers and thunderstorms along the leading edge of the
strongest ascent attendant to the shortwave trough moving through
the Great Basin and central Rockies should emerge into a diurnally
destabilized and moderately buoyant airmass from northeast CO into
eastern WY and the NE Panhandle during the late afternoon/early
evening. This could result in reintensification, and a risk for both
large hail and damaging gusts across the region throughout the
evening. Most of the guidance was overly aggressive with
destabilization and buoyancy across this region yesterday, and there
is some concern that cloud cover could again limit heating. That
being said, there is a pocket of greater low-level moisture across
SD and the region is currently under widely scattered cloud cover.
Enhanced westerly flow atop low-level easterlies will support at
least moderate deep-layer shear, so any updrafts that can mature
should be able to organize, with an attendant risk for large hail
and damaging gusts.
...AZ...
12Z PHX sounding sampled moderate mid-level moisture atop warm and
dry low levels. Scattered thunderstorm development is anticipated
across much of the region. Vertical shear is weak and a largely
disorganized storm mode is anticipated. Still, given the high storm
bases and steep low-level lapse rates, isolated strong to severe
gusts are possible this afternoon and evening.
..Mosier/Moore.. 08/29/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TVDhBW
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 29, 2026
SPC Aug 29, 2026 1630 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)




















