Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1248 AM CDT Mon May 25 2026

Valid 251200Z - 261200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATE THIS
AFTERNOON INTO TONIGHT ACROSS PARTS OF THE RIO GRANDE
VALLEY...CENTRAL GREAT PLAINS AND UPPER GREAT LAKES REGION...

...SUMMARY...
The risk for organized severe thunderstorm development appears low
across much of the U.S. today through tonight.

...Discussion...
Amplification within the westerlies across the northern mid-latitude
Pacific is ongoing.  Near the leading edge of this regime, a
significant short wave trough and embedded mid-level cyclone are now
digging toward the Pacific Northwest coast, and forecast to progress
inland across coastal areas later today through tonight.  As this
occurs, the center of broad, weak troughing emerging from the
subtropical eastern Pacific is forecast to sharpen some, along a
negatively tilted axis across the southern Great Basin through
northern Mexican Plateau by daybreak Tuesday.  

Downstream, weak troughing across eastern Texas and the western Gulf
Basin will tend to slowly shift north-northeastward toward the lower
Mississippi Valley, as a high remains prominent across the
subtropical western Atlantic.  In higher latitudes, mid-level
ridging is forecast to continue to build to the east the Canadian
and northern U.S. Rockies.  This will include further mid-level
height rises across the Missouri Valley through Upper Midwest and
adjacent Great Lakes region.

In lower levels, a cold front likely will advance inland across
Washington, Oregon and much of northern California, while surface
troughing deepens across much of the Great Basin and northern
Rockies through northern Great Plains.  However, seasonably moist
boundary-layer air appears likely to generally remain confined to
portions of the southern Great Plains and lower Mississippi Valley
through Southeast and Mid Atlantic.

...Minnesota Arrowhead/adjacent Upper Great Lakes...
Mid-level heights are forecast to continue to rise across the region
today, even as a fairly significant short wave trough and associated
forcing for ascent dig across northwestern Ontario, generally well
to the north of the upper Great Lakes region.  Even so, convection
allowing and related machine learning guidance continue to suggest
that isolated thunderstorm development is possible as far south as
the Minnesota Arrowhead vicinity, in an environment that could
become supportive of a supercell.  As a result, 5 percent severe
weather probabilities will be maintained.  However, given the lack
of better available low-level moisture and the spread evident within
guidance concerning potential destabilization, these may be too
high.

...Central Great Plains and adjacent Middle Missouri Valley...
Calibrated thunderstorm probabilities from most ensemble output
suggest that widely scattered thunderstorm development is probable
by late this afternoon, in a corridor of stronger potential
boundary-layer destabilization within the lee surface troughing,
from portions of southwestern Nebraska through southwestern
Minnesota/northwestern Iowa.  If inhibition associated with
continuing mid-level height rises and more substantive
lower/mid-tropospheric warming is overcome, thermodynamic profiles
may be conducive to locally strong to severe surface gusts and some
hail, particularly where a narrow corridor of better low-level
moisture is maintained across the northeastern Nebraska through
southern Minnesota vicinity.

...Parts of southwestern Texas into south central New Mexico...
Stronger deep-layer layer shear and forcing for ascent, within the
exit region of a strong subtropical jet nosing into the northern
Mexican Plateau, may support and enhance thunderstorm development
across parts of northeastern Chihuahua into adjacent portions of the
Rio Grande Valley by late this afternoon.  This probably will be
rooted within a weakly unstable, but deeply mixed boundary layer
supportive of at least a risk for strong to severe wind gusts.

..Kerr/Chalmers.. 05/25/2026

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1248 AM CDT Mon May 25 2026

Valid 261200Z - 271200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
SOUTHWEST TEXAS...

...SUMMARY...
Scattered severe storms will be possible across western Texas into
southeastern New Mexico Tuesday afternoon and evening. Across this
region, large hail, severe gusts, and perhaps a tornado will be
possible.

...Synopsis...
The pattern on D2/Tuesday will include a deepening mid-level low
across the Pacific Northwest and height rises with a building high
downstream across the central/northern US. A shortwave with multiple
embedded vorticity maximas will move across Texas. This will be the
focus of scattered severe thunderstorm development by the afternoon.


...Eastern New Mexico and Western Texas...
As forcing for ascent increases across Texas Tuesday afternoon,
widely scattered thunderstorm development is expected from the Davis
Mountains to the Edwards Plateau and to the southern Permian Basin.
Moderate instability and steep low to mid-level lapse rates are
forecast across the region, with increasing deep layer shear to
around 30-40 kts. Mode will likely include a few supercells and
multi-cell clusters capable of large to very large hail and severe
wind gusts. Forecast soundings indicate low-level SRH may increase
through the late afternoon/evening, which could support some
increase in tornado potential.

Through time, cells are progged to cluster and move downstream into
portions of south Texas. Should cells be able to maintain cold pool
organization, damaging wind potential may extend to the southern
Texas coast. The Slight Risk remains unchanged but a minor eastward
expansion was given to the Marginal Risk to account for this
potential. 

...Montana...
Scattered thunderstorm activity is expected with the upper trough
across portions of southern Idaho into Montana. Modest instability
and strengthening deep layer shear amid deeply mixed profiles may
allow for a few stronger storms with potential for marginally severe
hail and severe gusts.

..Thornton.. 05/25/2026

Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0219 AM CDT Mon May 25 2026

Valid 271200Z - 281200Z

...NO SEVERE THUNDERSTORM AREAS FORECAST...

...SUMMARY...
Scattered thunderstorm activity will be possible from the Pacific
Northwest to the Intermountain West and from the Plains to the
Southeastern US on Wednesday. Organized severe potential is expected
to remain low.

...Discussion...
The western US trough will become cut off and shift southward into
the Great Basin on Wednesday, with scattered thunderstorm activity
continuing across portions of the Pacific Northwest into the
Intermountain West. A few strong gusts will be possible with storms
across northern Idaho into western Montana. Overall, deep layer
shear will largely be west of the marginal instability across
central/eastern Montana, which will likely keep organized severe
potential low. Model guidance that typically exhibits a moist-bias
does suggest that higher instability does nudge into northern
Montana and northern Idaho. Should more model consensus in this
scenario increase, low probabilities may need to be introduced in
upcoming outlook updates.

Widely scattered thunderstorm activity will be possible across
portions of the central/southern Plains into the southeast Wednesday
afternoon. Overall, weak flow beneath the mid-level ridge will keep
severe storm potential low. 

A few stronger storms will be possible across the Mid Atlantic as
enhanced westerly flow from a trough across the northeast
overspreads the region. Though deep layer shear will be around 35-40
kts, forecast soundings depict cloudy conditions through the
morning, with skinny and elongated CAPE profiles and only marginal
instability. This will likely temper the severe potential, though a
few strong gusts will remain possible.

..Thornton.. 05/25/2026