SPC AC 220600
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Thu Oct 22 2026
Valid 221200Z - 231200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL AND
EASTERN ARIZONA INTO WESTERN NEW MEXICO...
...SUMMARY...
Scattered severe thunderstorms are expected across the Southwest and
Four Corners area today into tonight with the most intense storms
likely across parts of Arizona and New Mexico. All severe hazards
will be possible.
...Southwest and Four Corners...
The deep upper low initially over the CA coast will move inland and
continue eastward through the day, slowly weakening into an open
wave. A belt of enhanced southerly mid-level flow (70+ kt) along the
eastern periphery of the cyclone will remain in place over the
Southwest and Four Corners. Several embedded shortwave perturbations
will rotate around the cyclone, aiding in continued low-level
southerly flow across eastern AZ and southwest NM. Here, surface
dewpoints in the upper 50s to low 60s F and diurnal heating should
contribute to moderate buoyancy amid deep and strongly veering wind
profiles favorable for severe storms.
One or more bands of convection are likely to be ongoing across
central/eastern AZ early this morning along a weak surface trough.
Cooling mid-level temperatures ahead of the approaching low and
persistent upslope flow along the central and southern portions of
the Mogollon Rim will maintain buoyancy through the diurnal minimum
with reintensification of these storms likely as heating develops
over the lower deserts. Storms will likely be supercellular
initially. Large hail (perhaps to around 2 inches) and a couple of
tornadoes will be the main concern, focused where the largest
buoyancy and strongest low-level shear will overlap in southeastern
AZ. With time, increasingly meridional flow and numerous storm
interactions will favor more linear modes and perhaps a transition
to a greater damaging wind threat by later in the afternoon.
Farther north into the Great Basin, sufficient destabilization for
more than sporadic severe storms is much less certain owing to lower
surface dewpoints and significant cloud cover. Still, model guidance
shows a few hundred J/kg of MLCAPE may develop with pockets of
better heating from eastern NV, UT and into southwestern CO. Flow
aloft will remain fairly strong (50-60 kt) helping to elongate mid
and upper-level hodographs. DPVA and upslope trajectories should
support numerous showers/thunderstorms with some potential for
organization into clusters or supercell structures. Damaging wind
gusts are the most likely hazard, though marginally severe hail is
also possible with any of the stronger rotating storms into the
evening.
...Southern California...
As the upper-level low moves overhead during the afternoon, cold
mid-level temperatures (around -20C at 500 mb) and modest surface
heating will support weak destabilization with MLCAPE of 500-750
J/kg. Low-topped convection near the coast may be ongoing early and
continue into the early afternoon before mid-level ascent begins to
decrease. Given the ambient vorticity with the upper-low and local
terrain effects, a brief tornado is possible with the strongest
storms along with isolated wind damage potential. Severe potential
should rapidly diminish as the upper trough moves eastward late
through the afternoon and into the evening.
..Lyons/Jirak.. 10/22/2026
NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
SPC AC 220600
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Thu Oct 22 2026
Valid 231200Z - 241200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF NEW
MEXICO...
...SUMMARY...
Isolated severe thunderstorms are possible across portions of New
Mexico on Friday.
...Synopsis...
A broad upper trough will slowly progress over the Rockies on
Friday, with a lead mid-level impulse poised to eject into the
northern Plains while a lagging 500 mb cut-off low drifts eastward
across the Desert Southwest. Given adequate low-level moisture
return and deep-layer ascent ahead of the longwave mid-level trough,
thunderstorms will be possible across much of the Rockies and the
central to northern Plains. Isolated severe thunderstorms are
possible across portions of NM, where locally greater moisture and
instability reside.
...Western into central New Mexico...
As the aforementioned leading mid-level impulse departs the Rockies
and the cut-off low approaches NM, 50+ kt southwesterly 500 mb flow
will overspread the Desert Southwest, where low to mid 50s F surface
dewpoints amid southeasterly surface flow will be in place. Given
7-7.5 C/km mid-level lapse rates, up to 1000 J/kg MLCAPE may
manifest amid appreciably curved and elongated hodographs, with
30-40 kts of effective bulk shear likely. By afternoon,
thunderstorms should develop and intensify with diurnal heating.
Given the aforementioned vertical shear/buoyancy, some supercell
structures should develop, accompanied by an isolated severe
wind/hail threat, and a tornado is also possible.
..Squitieri.. 10/22/2026
WUUS02 PTSDY2
SPC AC 220718
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0218 AM CDT Thu Oct 22 2026
Valid 241200Z - 251200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR CENTRAL NEW
MEXICO INTO FAR WEST TEXAS...
...SUMMARY...
Isolated severe wind/hail or a tornado are possible across portions
of central New Mexico into Far West Texas on Saturday.
...Synopsis...
A mid-level cut-off low will traverse the Desert Southwest and
impinge on the southern High Plains on Saturday. This will provoke a
low-level mass response in the form of northwestward moisture
advection through the day. Cooler temperatures and stronger flow
aloft associated with the cut-off low will overspread the low-level
moisture, resulting in enough buoyancy and shear overlap to support
an isolated severe threat.
...Portions of central NM into Far West TX...
Through the afternoon, 40-50 kt south-southwesterly mid-level flow
and 7+ C/km mid-level lapse rates from the approaching cut-off low
will overspread mid to upper 50s F surface dewpoints and backed
southeasterly surface winds. With surface heating of the
aforementioned moist low-level airmass, MLCAPE may exceed 1000 J/kg,
perhaps locally exceeding 1500 J/kg in spots given locally greater
insolation. Veering and strengthening flow with height will yield
modestly curved and elongated hodographs, with over 40 kts of
effective bulk shear expected. Multicells and perhaps a couple of
supercells may develop and persist for at least a few hours before
merging into a loosely organized line of thunderstorms. Storms
should be at their strongest during their supercell stage, capable
of producing isolated severe hail/wind and perhaps a tornado.
..Squitieri.. 10/22/2026
WUUS03 PTSDY3
NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 1930Z
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