SPC AC 220550
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1250 AM CDT Tue Sep 22 2026
Valid 221200Z - 231200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE SOUTHEAST...AND IN THE VICINITY OF NORTH-CENTRAL AND
NORTHEASTERN UTAH....
...SUMMARY...
Thunderstorms with isolated severe wind gusts are possible today
across parts of the Southeast, and in the vicinity of north-central
and northeastern Utah.
...Southeast...
At the surface, a cold front will advance southward into the
Southeast today. The position of the front by afternoon will be from
the northern Gulf Coast States into southern Appalachians. Warming
surface temperatures and increasing low-level convergence near and
ahead of the boundary will result in scattered thunderstorm
development this afternoon. Surface dewpoints across the moist
airmass will mostly range from the mid 60s to mid 70s F. This will
aid destabilization, with MLCAPE expected to peak in the 1500 to
2500 J/kg in most areas ahead of the front. Although deep-layer
shear will be limited, the thermodynamic environment will be able to
support isolated severe wind gusts with convection that develops
within the strongest localized instability.
...North-central and Northeastern Utah/Far Southwest Wyoming...
A mid-level trough and low pressure center will move northeastward
across the Intermountain West today. Ahead of the system, a surface
low will deepen across western Utah. To the east and northeast of
the low, surface dewpoints will range from the mid 40s to mid 50s F.
This will be enough for the development of weak instability by
afternoon. MLCAPE is forecast to increase to around 1000 J/kg over
much of north-central and northeast Utah, as a cold pocket
associated with the approaching upper-level low begins to affect the
area. The Salt Lake City RAP forecast sounding at 21Z has 0-6 km
shear near 40 knots with steep low to mid-level lapse rates in the 7
to 8 C/km range. This should support an isolated potential for
supercells. Hail and isolated severe gusts would be the primary
threats.
..Broyles/Thornton.. 09/22/2026
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
SPC AC 220537
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1237 AM CDT Tue Sep 22 2026
Valid 231200Z - 241200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe thunderstorms are not expected tomorrow (Wednesday).
...Synopsis...
An upper low will meander over the eastern U.S. while an upper ridge
builds over the Plains states, and an upper trough gradually
amplifies over the Pacific Northwest tomorrow (Wednesday). Surface
high pressure will build over the northeastern U.S. and Interior
West, limiting severe thunderstorm potential. One small exception
may be along the windward side of the southern Appalachians,
particularly over eastern TN. Here, a surface inverted trough will
allow low-level moisture to advect northward, with mid 60s F
dewpoints boosting MLCAPE to near 1000 J/kg (albeit tall and thin
profiles). A mid-level impulse and accompanying 30+ kt 500 mb jet
will yield modestly elongated hodographs and 30 kts of effective
bulk shear. CAM guidance consensus depicts pulse cellular and
multicellular development by afternoon. An instance of hail
approaching 1 inch in diameter or a strong gust causing tree/wire
damage cannot be ruled out.
..Squitieri.. 09/22/2026
WUUS02 PTSDY2
SPC AC 220718
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0218 AM CDT Tue Sep 22 2026
Valid 241200Z - 251200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
...SUMMARY...
Severe thunderstorms are not expected on Thursday.
...Synopsis...
Upper troughing will prevail over the East and West Coasts while
upper ridging continues over the Plains states. West of the Rockies,
an embedded mid-level impulse will track northeastward across the
Southwest, bringing widespread showers and widely scattered
thunderstorms. However, buoyancy and shear should be too meager to
support an organized severe threat.
..Squitieri.. 09/22/2026
WUUS03 PTSDY3
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 1930Z
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