ACUS03 KWNS 221928
SWODY3
SPC AC 221927

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0227 PM CDT Sat Aug 22 2026

Valid 241200Z - 251200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN GREAT BASIN TO THE HIGH PLAINS AND NORTHERN
PLAINS...PARTS OF THE GULF COAST...AND MAINE...

...SUMMARY...
Thunderstorms with at least isolated severe gusts/hail are possible
across the northern Great Basin to the High Plains and northern
Plains Monday afternoon and evening. A couple of damaging gusts may
also occur with storms in Maine and along parts of the Gulf Coast.

...Synopsis...
An upper ridge will remain in place across the western and central
CONUS while an upper trough begins to eject into the Atlantic from
New England on Monday. The embedded impulse responsible for cresting
the ridge over the northern Rockies and encouraging severe storm
development on Day 2 (Sunday) will overspread the northern High
Plains on Monday. Weak lee troughing over the Plains will encourage
modest low-level moisture advection beneath stronger westerly flow
aloft, resulting in enough deep-layer ascent, amid coinciding
buoyancy and vertical wind shear, to support isolated strong to
severe thunderstorms.

...Central High Plains to the northern Plains...
Upslope flow of 60s F surface dewpoints beneath 8 C/km mid-level
lapse rates along the central and northern High Plains will yield
2000-3000 J/kg MLCAPE as a mid-level impulse begins to overspread
the region. Over 30 kts of 500 mb flow and resultant deep-layer
shear will coincide with this buoyancy, supporting the development
of multicells and perhaps supercells by late Monday afternoon.
Should more sustained supercells develop, an instance or two of 2+
inch diameter hail or a 75+ mph gust cannot be ruled out given the
aforementioned mid-level lapse rates. Slight risk probabilities may
be needed in future outlooks pending higher confidence in greater
storm coverage.

...Parts of the northern Great Basin to central Rockies...
A deep and dry boundary layer should develop by afternoon peak
heating, resulting in inverted-V thermodynamic profiles from the
northern Great Basin into the central Rockies. Stronger westerly
mid-level flow will overspread this dry and unstable boundary layer,
promoting elongated hodographs and the tendency for storms to
organize into multicells. Given the organized storm mode and
evaporative cooling potential with the dry boundary layer in place,
a few severe gusts may occur with the stronger storms.

...Maine...
Deep-layer ascent ahead of the ejecting upper trough will support
scattered thunderstorm development during the late morning into the
afternoon hours. A belt of 60 kt 500 mb southwesterly flow will
pivot around the upper trough and overspread Main during the
afternoon, when buoyancy will be maximized. MLCAPE may exceed 750
J/kg with over 50 kts of effective bulk/speed shear given highly
elongated hodographs. Therefore, any storms that develop may become
multicellular or transient supercellular in nature, posting an
isolated damaging gust/hail threat through the afternoon.  

...Parts of the Gulf Coast...
Another hot and humid day is expected along the Gulf Coast, where
strong surface heating amid mid 70s F dewpoints will yield MLCAPE
over 2000 J/kg. Despite weak tropospheric flow, enough
moisture-fueled buoyancy will support the potential for wet
downbursts capable of damaging gusts during the afternoon.

..Squitieri.. 08/22/2026

$$