LIVE MAP (ABOVE) ... SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0742 AM CDT Sun Aug 16 2026
Valid 161300Z - 171200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE OHIO VALLEY...CENTRAL APPALACHIANS...MID-ATLANTIC...AND CENTRAL
HIGH PLAINS...
...SUMMARY...
Thunderstorms with damaging wind gusts will be possible from this
afternoon into early evening over parts of the Ohio Valley and
Mid-Atlantic. Large hail and isolated severe wind gusts will also be
possible in parts of the central High Plains.
...Lower MO Valley through the OH Valley into the Mid-Atlantic...
Satellite and regional radar imagery shows several vorticity maxima
embedded within the moderate westerly flow aloft that extends from
the central Plains across the OH Valley and into the Mid-Atlantic.
The strongest vorticity maximum is currently moving through
north-central KS and south-central NE, while more subtle maxima
exist across western IL, southwestern Lower MI/far northern IN, and
western PA. Each of these features will likely contribute to showers
and thunderstorms later today. The most consequential of these
storms will likely occur in tandem with the western IL and
southwestern Lower MI waves as they interact with a moist and
diurnally destabilized airmass from the middle OH Valley into the
Mid-Atlantic. Airmass destabilization appears likely by the early
afternoon, with renewed thunderstorm development anticipated from
southeast Lower MI into southern IN. Moderate vertical shear will be
in place, supporting a predominantly multicellular mode. Mid-level
winds may increase slightly throughout the afternoon, and a
supercell or two is possible over southern OH. A trend towards
clustering and the development of linear segments is anticipated
over time, with damaging gusts as the primary risk throughout the
day.
These storms will continue eastward across WV into Mid-Atlantic
during the late afternoon/early evening. Moderate buoyancy will
support storm persistence and the potential for continued damaging
gusts. Additional thunderstorm development is possible ahead of
these clusters in areas of low-level convergence during the
afternoon. Moderate vertical shear could support a few more
organized storms, with water-loaded downbursts as the primary severe
risk. A tornado or two is also possible, particularly across
northern VA where southerly surface winds could result in adequate
low-level hodograph curvature.
Farther west (across the Lower MO Valley), the well-defined
vorticity maximum currently over north-central KS/southern-central
NE is forecast to be east of the region by the late afternoon, but
airmass destabilization in its wake is uncertain. If the airmass can
recover, additional thunderstorms are likely along a cold front
moving into the region this evening. Strong buoyancy will support
robust updrafts, but modest vertical shear will keep storm
organization limited. If thunderstorms form, a few strong gusts are
possible across this region this evening.
...Northern/Central High Plains...
Scattered thunderstorm development in anticipated this afternoon
across the northern and central High Plains. Thunderstorms over the
northern High Plains will be supported by low-level convergence
along the western edge of the moist airmass over the Plains.
Moderate vertical shear could support a few supercells capable of
hail and strong gusts, but modest buoyancy should keep the overall
severe threat isolated.
Thunderstorm development farther south across the central High
Plains will result from a combination of moist low-level easterlies,
westerly flow aloft and orographic effects. Here, more cellular
development over the high terrain and immediate foothills could pose
a risk for large hail before transitioning towards more linear
structures with strong gusts as the primary severe risk.
..Mosier/Dean.. 08/16/2026
Read more CHECK UPDATE ZOOM GRAPHIC
http://dlvr.it/TV2VRg
Windy.com Temps | Gusts | WU KORD KPWK |
CLICK for this month's BIG night sky ... | RADAR FULL MAP SCREEN |
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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)
Sunday, August 16, 2026
SPC Aug 16, 2026 1300 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)




















