RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Sun Jul 26 18:16:02 UTC 2026.
No Mesoscale Discussions are in effect as of Sun Jul 26 18:16:02 UTC 2026.
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1110 AM CDT Sun Jul 26 2026
Valid 261630Z - 271200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS THE
UPPER MIDWEST/GREAT LAKES...
...SUMMARY...
Severe thunderstorms capable of large to very large hail, damaging
winds (possibly 75+ mph), and tornado risk are expected from the
upper Mississippi Valley and Great Lakes southwestward into
Nebraska, mainly this afternoon and tonight.
...Upper Midwest/Great Lakes...
Initial supercell storms are expected to develop across northern
MN/WI later this afternoon, aided by a favorably timed shortwave
impulse rounding the Plains upper ridge. Another MCV/shortwave
impulse located over the Dakotas at midday will also spread
east/southeast across southern/central MN this afternoon. These
features will provide support for one or more focused areas of
thunderstorm development. Initial supercells will pose an
all-hazards risk, including locally severe wind gusts, very large
hail, and a couple of tornadoes. With time into the evening, initial
supercells may grow into one or two small bowing MCSs. This storm
mode transition will support an increased risk for intense damaging
wind swaths this evening into tonight as convection spreads
southeast along a strong instability/moisture gradient across WI and
the Lake Michigan vicinity.
...Mid-Mississippi/Lower Ohio/Tennessee Valleys...
Multiple areas of strong to severe storms will be possible this
afternoon into tonight from near the MS River into IL/IN/KY/TN.
Thunderstorm development may be aided by a weak shortwave
impulse/MCV migrating southeast from IA at midday and into the Lower
OH Valley this evening. Storms are expected to develop along a
corridor of differential heating near/just east of the MS River
where mostly clear skies this morning have already resulted in
temperatures approaching 85-90 F, while scattered clouds further
east will maintain somewhat lower high temperatures. Thunderstorm
clusters this afternoon will pose a risk for severe/damaging wind
gusts. Sufficient clustering may occur and some upscale development
into a forward propagating bow may occur across the Lower Ohio
Valley vicinity this evening, and wind probabilities have been
increased to 30 percent for parts of southern IL/IN and western KY.
This activity could be maintained southward during the overnight
hours as far south as northern AL/GA given favorable instability and
sufficiently strong northwesterly flow aloft. Damaging wind gusts
could persist with this activity as it spreads south/southeast
across TN into AL/GA toward early Monday morning.
...NE/SD/IA...
A deeply mixed and hot boundary layer will develop this
afternoon/early evening in the vicinity of a weak surface trough
from NE into southeast SD/northwest IA. Very steep lapse rates aloft
will foster 1500-2000 J/kg MLCAPE. Vertically veering wind profiles
and increasing northwesterly flow aloft will provide 25-35 kt
effective shear magnitudes and a few organized cells/clusters may
develop by late afternoon. Damaging wind gusts of 60-80 mph would be
the main hazard with this activity. While temperatures are somewhat
warm aloft, the strongest storms could produce sporadic large hail.
...Mid-Atlantic/Carolinas/Southeast GA/Northern FL...
Upper troughing will persist today across the East, though some
enhancement to northwesterly flow aloft is expected. Relatively cool
conditions, weak lapse rates, and the potential influence of smoke
will temper destabilization across the Mid-Atlantic. Nevertheless,
MLCAPE 1000 J/kg amid 25-35 kt of effective shear may support
occasional organized storms capable of producing locally damaging
gusts.
Stronger heating/destabilization is expected farther south across
the Carolinas into GA/FL. Deep-layer flow/shear will be somewhat
weaker compared to farther north, but may still be sufficient for
transient storm organization with sporadic locally damaging winds
possible.
...Southeast MT/northern WY/Black Hills vicinity...
High-based convection is expected to develop this afternoon along
the northern periphery of the upper ridge, with the greatest storm
coverage expected across parts of northern Wyoming and southern
Montana. Overall buoyancy is expected to remain weak, but inverted-v
profiles will support a threat of strong to localized severe gusts
as storms spread eastward toward the Black Hills before weakening
into mid/late evening.
..Leitman.. 07/26/2026
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1213 PM CDT Sun Jul 26 2026
Valid 271200Z - 281200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE GREAT
LAKES INTO PARTS OF THE OHIO VALLEY...
...SUMMARY...
Severe storms capable of damaging winds and large hail are possible
across the Great Lakes into the Ohio Valley Monday into Monday
night. More sporadic occurrences of damaging wind appear possible in
the Mid-Atlantic, Tennessee Valley, central High Plains, and
southeast Arizona.
...Great Lakes southward across the Ohio and Tennessee Valleys...
Early day storms are possible from southern WI into northern IL
Monday, associated with a warm advection regime at 850 mb with
modest westerly winds at that level. The overall severe risk is
expected to be marginal for hail or wind with any such activity.
Later in the day, a surface trough is forecast to develop roughly
from Lake Huron southwestward into southern WI/northern IL, and
southwesterly low-level winds will continue to spread moisture
eastward into Lower MI, IN and OH. Scattered cells are forecast to
develop near this surface trough/wind shift, aided by the late upper
trough amplification. Storms are expected from eastern WI across
Lake MI and into Lower MI by late afternoon, and supercell mode
appears most likely given up to 50 kt deep-layer shear. A low-level
jet out of the west at over 30 kt is expected over IL, with
increasing speeds into IN and OH into the evening as the upper
trough amplifies and convection possibly merges into clusters or an
MCS. Models vary on how much storm coverage will extend into IL,
with the most likely areas from southeast WI across southern Lake MI
and into southern Lower MI, northern IN and OH.
Despite relatively warm conditions aloft, the elongated hodographs
from mid to upper levels, and substantial boundary-layer moisture
suggest cells may produce large hail. A tornado or two may occur as
well late afternoon through early evening, with storm mergers
overnight aiding outflow/severe gust potential. A categorical
upgrade is possible for parts of the risk area in later outlooks as
predictability increases.
...Central High Plains...
Weak high pressure will exist over the northern Plains with a front
pushing south across I-80. Surface winds will back to eastern late
in the day, with corridor of higher dewpoints over southern NE and
northern KS, extending into northeast CO.
Strong heating will occur beneath the upper ridge, and an uncapped
and unstable air mass will develop. Apart from the monsoonal regime
over the Rockies, additional multicellular storms are expected after
21Z from northeast CO into southwest NE and northwest KS. The hot
temperatures near the moist plume and weak flow aloft will support
locally severe outflow winds.
...Southeast Arizona...
Isolated severe gusts cannot be ruled out over far southeast AZ as
midlevel moisture and daytime heating leads to scattered storms over
the higher terrain. Cells are expected to move northwestward, with
PWAT over 1.25" and steep low-level lapse rates supporting strong
outflows.
..Jewell.. 07/26/2026
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook CORR 1
NWS Storm Prediction Center Norman OK
1214 PM CDT Sun Jul 26 2026
Valid 261700Z - 271200Z
CORRECTED FOR CRITICAL HEADLINE
...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE NORTHERN SIERRA INTO
THE HARNEY BASIN...
...CRITICAL FIRE WEATHER AREA FOR FAR NORTHERN MONTANA...
Today's fire weather outlook remains on-track, with only minor
modifications made to the outlook areas based on the latest
high-resolution weather ensembles and fuel intel. The combination of
hot, dry, and breezy conditions amidst receptive fuels will promote
a broad area of Elevated fire weather conditions from the western
Great Basin into the northern High Plains through much of the day.
Critical fire weather conditions are most likely across portions of
northern Montana, and parts of the northern Sierra into the Harney
Basin, where stronger winds are forecast this afternoon into the
evening. Moderate to poor RH recoveries (20-30%) are also expected
across portions of western NV tonight into tomorrow morning.
Scattered, potentially high-based thunderstorms are expected across
portions of southern Montana and surrounding areas today. However,
it remains unclear how efficient any lightning-induced ignitions
will be due to recent rainfall, with quantitative precipitation
estimates suggesting widespread 0.25-0.5 inches of rainfall over the
last 24 hours and localized values over 1 inch. While an isolated
dry thunderstorm area was not introduced, a few lightning ignitions
remain possible - especially in areas that received little rainfall
over the past few days and/or along the periphery of any heavier
thunderstorm cores today.
..Elliott.. 07/26/2026
.PREV DISCUSSION... /ISSUED 1122 PM CDT Sat Jul 25 2026/
...Synopsis...
An upper ridge will remain in place across the western CONUS today,
with strong mid-level flow cresting the ridge across the West Coast
into the northern Rockies. A dry and deep boundary layer will
encourage downward mixing of this stronger flow aloft along the
periphery of the ridge by afternoon peak heating. A broad area of at
least 15 mph sustained southwesterly surface winds amid 20 percent
RH will overspread portions of the western Great Basin into northern
High Plains, warranting Elevated highlights given dry fuels.
Guidance consensus also depicts locally stronger winds across
portions of northern Montana, and parts of the northern Sierra into
the Harney Basin, justifying the continuation of Critical
highlights.
Another day of scattered, potentially high-based thunderstorms are
expected across portions of southern Montana. However, given less
receptive fuels in this area, especially with some accumulated
rainfall from the prior day's storms, it is unclear how efficient
lightning-induced ignitions will be. Therefore, isolated dry
thunderstorm highlights have been withheld this outlook.
...Please see www.spc.noaa.gov/fire for graphic product...
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