838
ACUS01 KWNS 161645
SWODY1
SPC AC 161644

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1144 AM CDT Sun Aug 16 2026

Valid 161630Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE FRONT
RANGE AND CENTRAL/NORTHERN HIGH PLAINS AND OHIO
VALLEY/MID-ATLANTIC...

...SUMMARY...
Thunderstorms with damaging wind gusts will be possible this
afternoon and early evening over parts of the Ohio Valley and
Mid-Atlantic. Large hail and isolated severe wind gusts will also be
possible across the Front Range and central/northern High Plains.

...Upper Ohio Valley to Appalachians and Mid-Atlantic/Carolinas...
An MCV persists at midday across far southeast Michigan and northern
Ohio, with some recent uptick in convection ahead of it across
northern Ohio. Reference Mesoscale Discussion 1195 for short-term
details regarding a further increase in severe potential through
early/mid-afternoon within this regional corridor.

While storms have weakened, showers/cloud cover remain prevalent
near/east of the Appalachians at midday across the Mid-Atlantic
region. This will tend to limit/delay destabilization in many areas
(especially with north-northeastward extent). That said, air mass
recovery/advection is expected from the west, with ample upstream
clearing per visible satellite imagery across the Cumberland Plateau
into parts of the Allegheny Plateau. Pending the timing/location of
destabilization, some terrain/lee trough-related development may
diurnally occur, although the most prevalent/more certain scenario
may be for potentially severe storms to spread into the region this
evening. Damaging winds will be the most common hazard regionally,
although a tornado could occur, attributable to MCV-enhanced flow
and/or with any storms interacting with the effective warm front
across the Mid-Atlantic region.

...Middle Mississippi Valley including Missouri/Illinois...
An MCV over the Nebraska/Kansas/Iowa/Missouri border vicinity late
this morning will likely continue generally eastward, while probably
largely maintaining its related belt of enhanced mid-level flow as
observed from regional WSR-88D VWP data. A key downstream
uncertainty is the midday persistence of weak convection across
eastern Missouri into west/southwest Illinois, and that mid-level
lapse rates are rather poor to its north aside from some lingering
cloud cover.

More certain/greater destabilization may occur to the west across
Missouri, with the southeastward-advancing front being a focus for
renewed thunderstorm development later this afternoon and evening
amidst moderate/locally strong buoyancy. Deep-layer shear will tend
to be limited to around 30 kt in most areas, although somewhat
stronger MCV-related winds aloft may support upwards of 35-40 kt
effective shear for any storms across northern Missouri into
west-central/southwest Illinois. Bouts of damaging winds are the
most likely hazard regionally.

...Front Range/Raton Mesa and northern/central High Plains...
A relatively similar pattern/scenario as prior few days will
continue regionally, except a somewhat more northward-extent of the
severe risk (such as Black Hills vicinity) and a trend toward a more
northerly component to the flow aloft across the north-central High
Plains. At least widely scattered thunderstorm development is
expected into mid/late afternoon spanning the Front Range/Raton Mesa
vicinity northward across eastern Wyoming/southeast Montana and the
Black Hills vicinity. In the presence of upwards of 1500-2000 J/kg
MLCAPE, moderate vertical shear (30-40 kt) could support a few
supercells capable of severe hail. Isolated damaging winds will be
possible. This includes the most probable zone for gradual
upscale-growing linear cluster(s) across the south-central High
Plains/Raton Mesa vicinity including southeast Colorado/northeast
New Mexico toward the Oklahoma/Texas Panhandles and far southwest
Kansas. A couple of southeastward-moving thunderstorm clusters
capable of wind/damage may also emerge this evening out of the Black
Hills vicinity/western Nebraska.

..Guyer/Chalmers.. 08/16/2026

$$