Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0744 AM CDT Thu Oct 22 2026

Valid 221300Z - 231200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
CENTRAL/EASTERN ARIZONA INTO WESTERN NEW MEXICO...

...SUMMARY...
Scattered severe thunderstorms are expected across portions of the
Southwest today into tonight, with the most intense cells forecast
across parts of Arizona and western New Mexico this afternoon and
evening. Large hail, damaging winds, and a few tornadoes all appear
possible.

...Southwest into the Great Basin...
Occasional supercells across portions of east-central AZ have
persisted through much of the early morning hours, aided by
continued large-scale ascent associated with a 50-70 kt
south-southwesterly mid-level jet and low-level upslope flow across
the Mogollon Rim. Strong deep-layer shear of 40-50+ kt and generally
long/straight hodographs at mid/upper levels noted on the latest
KFSX/KIWA VWPs will support organized updrafts through the remainder
of the morning amid 500-1500 J/kg of MUCAPE (greater with southward
extent). See Mesoscale Discussion 2396 for more details on the
short-term threat across AZ.

Current expectations are for additional intense thunderstorms to
develop by 18-21Z across the higher terrain of east-central AZ and
vicinity as an upper trough/low over CA moves inland over the Great
Basin. The mid-level jet attendant to the upper trough/low will also
translate eastward through the day, with strong deep-layer shear
remaining over a gradually destabilizing airmass. The primary severe
threat should remain large hail with any sustained supercells
(isolated 2+ inches possible). But, the risk for severe/damaging
winds may increase by mid to late afternoon as convection spreads
from eastern AZ into western NM, with some potential for clustering.
A few tornadoes also appear possible, mainly over east-central AZ
this afternoon when the best combination of greater boundary-layer
instability and low-level shear are forecast to overlap. While the
severe threat across these areas will peak in the mid to late
afternoon when instability is strongest, at least an isolated threat
should continue through much of the evening with eastward extent
into western/central NM before convection eventually weakens.

Farther north into the Great Basin, both low-level moisture and
related MLCAPE are generally more limited. Even so, multiple
corridors of isolated severe hail/wind potential may exist this
afternoon as convection develops ahead of the eastward-translating
upper trough/low amid strong southerly flow/shear through much of
the troposphere. Recent short-term guidance suggests a small cluster
may form and spread northeastward across northern NV into southern
ID, with some potential for strong to locally severe gusts.

...Coastal Southern California...
Additional organized bands of low-topped convection appear unlikely
this morning into the afternoon across coastal southern CA.
Therefore, the Marginal Risk has been removed with this update.

..Gleason/Kerr.. 10/22/2026