No watches are valid as of Sun Jul 26 17:17:02 UTC 2026.MD 1740 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR FAR NORTHEAST NORTH DAKOTA AND NORTHWEST MINNESOTA
Mesoscale Discussion 1740
NWS Storm Prediction Center Norman OK
1139 AM CDT Sun Jul 26 2026
Areas affected...far northeast North Dakota and northwest Minnesota
Concerning...Severe potential...Watch unlikely
Valid 261639Z - 261815Z
Probability of Watch Issuance...20 percent
SUMMARY...An isolated hail threat will exist through early afternoon
across far northeast North Dakota and northwest Minnesota.
DISCUSSION...An elevated supercell has shown some sign of
strengthening in the last hour as it moves from Manitoba into
northeast North Dakota. This supercell is elevated, within the post
outflow boundary airmass at this time. Already weak forcing, from
weak isentropic ascent, is expected to weaken further into the early
afternoon as low-level flow dissipates. This casts some uncertainty
as to the fate of this activity. However, the downstream airmass is
destabilizing and temperatures near 90 with dewpoints in the 70s may
be sufficient for surface-based storm development.
Given this uncertainty and isolated storm coverage, a watch is not
anticipated. However, if there are signs of surface-based transition
and/or additional storm development within the next 1 to 2 hours, a
watch may need to be considered.
..Bentley/Leitman.. 07/26/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DLH...FGF...
LAT...LON 49279830 49169559 48899438 48009442 47449501 47349663
47899755 49089833 49279830
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0759 AM CDT Sun Jul 26 2026
Valid 261300Z - 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 and Great Lakes...
Have upgraded portions of the region to an Enhanced Risk including
Wisconsin and nearby far eastern Minnesota and Upper Michigan. An
upper ridge will remain anchored from the Southwest into the
central Rockies and High Plains through tonight. Seasonably
strong northwesterly flow aloft will overspread a very warm, moist,
and unstable environment from parts of the Upper Midwest and Great
Lakes into the central Plains.
Aided by favorably-timed MCV/mid-level impulse, the most likely
initiation zone for diurnal storm development is expected to be
across northern Minnesota into Wisconsin. Initial intense supercell
development is expected in this zone, posing a threat of large to
very large hail, localized severe wind gusts, and potentially at
least some tornado risk. Upscale growth into one or more intense
wind-producing southeastward-moving clusters are expected into this
evening amidst the enhanced northwesterly flow aloft.
...Middle Mississippi Valley...
Residual MCV influences may semi-focus renewed thunderstorm
development into a very unstable environment this afternoon
regionally, with potential storm organization aided by semi-strong
mid/high-level winds for the season. Damaging winds would likely be
the most probable concern as storms potentially cluster and spread
south-southeastward.
...Nebraska/eastern South Dakota/western Iowa...
A somewhat separate area of potential severe-storm development is
expected from parts of central Nebraska into southeast South Dakota.
Initiation is expected near a weak surface trough as temperatures
warm to near/above 100 F as CINH erodes. MLCAPE of near/above 1500
J/kg and effective shear of 30-40 kt will favor development of a few
organized cells and/or clusters. Severe gusts of 60-80 mph appear to
be the most likely hazard within the hot/well-mixed environment.
Isolated hail may also occur with any supercell, even with rather
warm temperatures aloft.
...Mid-Atlantic into the Carolinas/Georgia/north Florida...
A seasonably deep upper trough will persist across much of the
eastern CONUS today. A modest increase in northwesterly mid-level
winds are expected from the Mid-Atlantic into the Carolinas, Georgia
and northern Florida.
Relatively cool conditions, weak lapse rates, and the potential
influence of smoke will temper destabilization across the Mid
Atlantic. However, MLCAPE increasing to near 1000 J/kg amid 25-35 kt
of effective shear may support occasional storm organization, with a
primary threat of locally damaging winds.
Stronger heating/destabilization is expected farther south across
the Carolinas into Georgia and Florida. Deep-layer flow/shear will
be somewhat weaker compared to areas farther north, but may still be
sufficient for transient storm organization and a localized
damaging-wind threat.
...Southern Montana/northern Wyoming/Black Hills...
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.
..Guyer/Wendt.. 07/26/2026
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
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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