RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Mon May 25 10:52:02 UTC 2026.
No Mesoscale Discussions are in effect as of Mon May 25 10:52:02 UTC 2026.
SPC 0730Z Day 3 Outlook
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
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0343 AM CDT Mon May 25 2026
Valid 281200Z - 021200Z
...DISCUSSION...
...D4/Thursday through D5/Friday...
The western low is expected to shift northward again and phase with
the northern jet stream D4/Thursday - D5/Friday. There is low
confidence in chances for strong to severe storms, pending details
on moisture, across the Intermountain West and northern Rockies.
Guidance suggests that as the western trough shifts northward and
weak disturbances rotate across the Rockies, lee troughing across
the Plains may strengthen D5/Friday, bringing a potential for low
end severe risk into the central/northern High Plains. For now
confidence in any corridors of organized severe risk remain too low.
A cold front will sag southward across the east coast D4/Thursday
through D5/Friday as enhanced flow digs an upper level trough across
Quebec southward into the eastern Great Lakes. Some low end severe
potential may accompany this frontal passage each day, but
uncertainty remains high in overlap of deep layer shear with better
moisture/instability.
...D6/Saturday through D8/Monday...
Toward the end of next weekend D7/Sunday through D8/Monday, ensemble
guidance is increasing in confidence for a large scale ridge to
build in across the central/western US with rising heights and
warming temperatures. Building surface high pressure across the
Midwest/Great Lakes may shunt moisture southward to the Gulf states.
Should this pattern continue to hold, severe potential will remain
low through much of the CONUS.
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0223 AM CDT Mon May 25 2026
Valid 251200Z - 261200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF NORTHWESTERN NEVADA
INTO SOUTHEASTERN OREGON...
...Synopsis...
A robust upper-level trough will dig into the Pacific Northwest
today as a weaker mid/upper trough and an associated plume of
enhanced mid/upper level moisture shift into the Southwest. Another
upper trough will transition quickly east/northeastward across
northern New England while ridging remains in place over the
Southeast and much of the High Plains. Chances for wetting rainfall
will continue across much of the East Coast and the South
along/ahead of a surface quasi-stationary boundary/cold front. A
second cold front will also begin to advance across the Pacific
Northwest in tandem with the aforementioned upper trough.
...Great Basin...
A strengthening surface pressure gradient ahead of an approaching
surface cold front will promote sustained southwesterly surface
winds of 20-25 mph, with above normal temperatures and minimum RH
values around 15% also expected. Recent fire activity suggests that
fuels are becoming more receptive to wildfire spread across this
region. This combination of winds/RH and cured/drying lower
elevation fuels will result in a critical fire weather threat from
northwestern Nevada into southeastern Oregon this afternoon. Deep
boundary layer mixing and strengthening southwesterly flow aloft may
also support occasional wind gusts to 30-35 mph. Elevated fire
weather conditions are also expected across adjacent portions of the
Great Basin where sustained southwesterly surface winds of 15-25 mph
are forecast to overlap reduced RH of 15-25%.
...Southwest...
A mid/upper trough and associated plume of greater mid-level
moisture will shift into the Southwest through today. This will
contribute to weak buoyancy and support isolated to widely scattered
thunderstorms over receptive fuels (ERCs around the 90th
percentile). Thunderstorms will initially be high-based, with a dry
boundary layer supporting evaporation of rainfall. More robust
boundary layer moistening and the potential for a more prolonged
convective event in some locations will support a mix of wet/dry
thunderstorms, with rainfall accumulations of up to 0.5" possible,
primarily from west-central New Mexico into east-central Arizona.
Minor trimming to the drawn area was done to account for recent
rainfall accumulation trends in the latest high-res guidance.
High-based thunderstorms with lower rainfall totals should still be
more prevalent along and south of the Mogollon Rim and along the
fringes of the deeper subtropical moisture plume across lower
elevation areas, where isolated Dry Thunderstorm highlights remain.
..Chalmers.. 05/25/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0226 AM CDT Mon May 25 2026
Valid 261200Z - 271200Z
...Synopsis...
A robust upper-level trough will shift southward into the Great
Basin on D2/Tuesday as a blocking ridge begins to establish over the
central CONUS. Weak upper troughing will also persist across the
southern High/Great Plains. Meanwhile, a surface low will develop
across the northern High Plains as a cold front progresses eastward
across the Great Basin. Additional chances for wetting
rainfall/thunderstorms are expected across the southern High Plains
in association with a passing shortwave trough and across much of
the Southeast.
...Northeastern Montana...
Increasing southeasterly flow ahead of an evolving lee
trough/strengthening surface low is expected across much of the
northern High Plains on D2/Tuesday, with sustained surface winds of
around 15-25 mph and occasional wind gusts up to 30 mph expected.
Greater low-level moisture is forecast to remain displaced to the
east across the Dakotas, with forecast guidance/soundings depicting
deep, well-mixed boundary layer profiles and RH reductions to near
15% across much of eastern/northeastern Montana. With dry fuels
across much of northeastern Montana, these conditions are expected
to support elevated to locally critical fire weather concerns
Tuesday afternoon. Consideration was given to a westward expansion
of elevated highlights; however, uncertainty regarding the
coverage/development of high-based convection in association with a
northward shifting mid-level shortwave trough also increases with
westward extent. Trends will be monitored for future outlook cycles.
...Great Basin...
As the aforementioned upper-level trough shifts southward into the
Great Basin on Tuesday, a deepening surface low will promote a
strengthening surface pressure gradient ahead of the eastward
progressing cold front. Sustained southwesterly surface winds of
20-30 mph are expected amid this strengthening gradient, with
well-mixed boundary layer profiles supporting RH reductions to
15-20% (locally lower). Accelerating mid-level flow may also support
occasional wind gusts to 30-35 mph (perhaps higher in exposed,
elevated terrain areas). With near critically dry fuels across the
region, these conditions are expected to support a broad area of
elevated fire weather concerns, with locally critical conditions
possible in areas of drier fine fuels.
..Chalmers.. 05/25/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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