No watches are valid as of Sat Jul 25 19:53:02 UTC 2026.MD 1730 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR CENTRAL MONTANA
Mesoscale Discussion 1730
NWS Storm Prediction Center Norman OK
0250 PM CDT Sat Jul 25 2026
Areas affected...Central Montana
Concerning...Severe potential...Watch possible
Valid 251950Z - 252145Z
Probability of Watch Issuance...60 percent
SUMMARY...Thunderstorm coverage and the potential for severe wind
gusts will increase over the next several hours across central
Montana. Watch issuance is probable.
DISCUSSION...Early attempts at sustained deep convection have been
evident across southwest to central MT over the past several hours.
Lingering inhibition has largely limited storm longevity and
intensity thus far; however, downstream of this activity
temperatures are slowly warming into the mid to upper 90s. While
some lingering inhibition likely persists, further heating over the
next few hours should erode inhibition and increase the likelihood
of sustained convection away from the terrain. Recent GOES imagery
shows a gradual uptick in cumulus across parts of ID and southwest
MT, hinting that thunderstorm coverage will likely increase in the
next 2-3 hours.
As thunderstorms spread east into the hotter and more deeply mixed
air mass, the potential for severe winds will increase (especially
for areas that have not been adversely impacted by outflow from
recently decayed convection). Given some degree of stronger
mid-level flow (30-35 knots near 500 mb per RAP analyses and
forecast soundings), loosely organized clusters appear possible, and
may be capable of producing wind gusts between 65-80 mph. Convective
trends will continue to be monitored, and watch issuance may be
needed when more widespread thunderstorm development becomes
imminent.
..Moore/Smith.. 07/25/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BYZ...GGW...TFX...MSO...
LAT...LON 46641229 46981201 47810953 47920867 47780768 47540722
47220680 46860658 46420653 46080665 45850698 45790733
45780793 45810849 45810911 45740976 45651016 45511080
45451136 45431174 45521204 45721228 46251240 46641229
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
MD 1729 CONCERNING SEVERE POTENTIAL...WATCH LIKELY FOR SOUTH-CENTRAL TO SOUTHEAST SOUTH DAKOTA
Mesoscale Discussion 1729
NWS Storm Prediction Center Norman OK
0215 PM CDT Sat Jul 25 2026
Areas affected...south-central to southeast South Dakota
Concerning...Severe potential...Watch likely
Valid 251915Z - 252045Z
Probability of Watch Issuance...95 percent
SUMMARY...80-100 mph winds are possible this afternoon and evening
from south-central to southeast South Dakota. A severe thunderstorm
watch will be needed in the next 1 to 2 hours.
DISCUSSION...A very hot environment is in place across South Dakota
with temperatures of 105 to 110F across southwest and south-central
South Dakota. The 18Z UNR RAOB shows nearly 2500 J/kg MLCAPE. This
may be somewhat artificially inflated by the low-level dewpoint
profile, but even after modifying this to something more realistic,
MLCAPE near 2000 J/kg seems likely. This is significantly less than
SPC mesoanalysis but is more congruent with current satellite and
radar imagery which show what appears to be surface-based storm
development within areas that currently indicate significant
remaining inhibition from SPC mesoanalysis.
These storms are developing on the leading edge of a mid-upper level
cirrus deck as ascent associated with a weak shortwave trough
emerges over the Plains. Expect these storms to continue to increase
in coverage, and considering the 50F temperature/dewpoint spreads,
expect outflow dominant storms and a congealing cold pool. There is
some uncertainty how the storms will evolve, but given the
environment with a hot and unstable airmass to the west and very
high moisture content to the east with moderate shear and very steep
lapse rates, expect an MCS to develop with the potential for intense
wind gusts (perhaps has high as 100 mph).
A severe thunderstorm watch will be needed for this threat in the
next 1 to 2 hours and a PDS severe thunderstorm watch may be
considered.
..Bentley/Smith.. 07/25/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FSD...ABR...LBF...UNR...
LAT...LON 44170221 44900061 45029856 44819662 43819654 43379694
43039743 42990042 43050140 43580230 44170221
MOST PROBABLE PEAK WIND GUST...85-100 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1137 AM CDT Sat Jul 25 2026
Valid 251630Z - 261200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR CENTRAL
INTO EASTERN SOUTH DAKOTA...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN CENTRAL AND
EASTERN MONTANA...
...SUMMARY...
Widespread severe gusts are possible across South Dakota late this
afternoon through the evening.
...SD into adjacent parts of IA/MN...
A prominent upper ridge centered over the central/southern Rockies
will feature the southern periphery of appreciably strong mid to
high-level flow extending from the Pacific Northwest across the
northern High Plains and into the north-central states. Late
morning surface analysis shows very hot temperatures ensuing across
western NE into the western half of SD with richer moisture (surface
dewpoints in the lower to mid 70s F) located over the eastern half
of NE/SD. Visible-satellite imagery shows some mid to high clouds
across northern WY moving towards the Black Hills. This patch of
clouds appears associated with a weak disturbance forecast to move
into western SD later this afternoon.
Downstream across SD, forecast soundings show very steep surface to
500-mb lapse rates developing as temperatures rise into the 100s F.
Expecting initially isolated to widely scattered storms to develop
near the Black Hills, as convective temperatures are breached.
Models show the gradual development of a cluster moving east across
SD early this evening. Have increased severe-wind probabilities to
account for observational and model-based trends towards an MCS
capable of peak gusts in the 75-90 mph range. This activity will
probably slowly weaken towards the MN/IA/SD border but perhaps
continue into early overnight with a wind threat.
...MT...
Isolated to scattered storms will likely form near the higher
terrain of southern MT later this afternoon with a gradual increase
in storm coverage as this moves east during the early evening. A
hot and well-mixed boundary layer will support severe gusts with the
stronger cores and associated outflow. There is some indication
this activity will cluster and potentially reach parts of
eastern/southeast MT by the late evening.
...Upper Midwest/Upper Great Lakes...
Conditional severe potential exists across parts of the Upper
Midwest spanning Minnesota to Upper Michigan into Wisconsin. Models
continue to show low storm chances as mid-level heights rise through
the late evening. Nonetheless, appreciable heating of a seasonably
moist boundary layer will result in strong potential buoyancy later
today into tonight. Elongated hodographs will support organized
storms capable of a wind/hail threat. Given a muted diurnal storm
signal in models, the greater chance for isolated storms appears to
be associated with warm advection activity late tonight.
...Northeast NV/northern UT/eastern ID...
Storm development is expected during the afternoon across parts of
northeast Nevada, along the western periphery of the upper ridge.
These storms will spread into adjacent parts of southeast Idaho and
northwest Utah with time. Isolated severe gusts may accompany the
stronger downdrafts.
...South-central/southeast AZ...
High-based convection is again expected across southeast Arizona
during the afternoon, with initial downburst potential. A modest
enhancement to easterly flow along the southern periphery of the
upper ridge may allow for localized strong to severe wind gusts to
spread westward into parts of south-central Arizona, before
convection weakens tonight.
..Smith/Moore.. 07/25/2026
SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1219 PM CDT Sat Jul 25 2026
Valid 261200Z - 271200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE MID
MISSOURI VALLEY ACROSS THE UPPER MISSISSIPPI VALLEY AND WESTERN
GREAT LAKES...
...SUMMARY...
Severe thunderstorms capable of large hail and damaging winds are
possible from the upper Mississippi Valley and Great Lakes into
portions of the mid Missouri Valley on Sunday and Sunday night.
...From eastern SD and NE to the Upper Great Lakes...
The forecast continues to have major uncertainties regarding
placement of the most likely severe storm corridors, with a wide
range of model solutions. In general, the most likely threat areas
include northern MN into WI and Upper MI, on the periphery of the
upper ridge and where stronger winds aloft will exist coincident
with strong instability, and from southeast SD into northeast NE
within a super-heated surface trough.
Beneath 40-50 kt midlevel northwesterlies, areas of strong
instability will develop with relatively steep midlevel lapse rates
and 70s F dewpoints, from parts of MN into WI. Models suggest
various storm clusters are possible late in the day, and these would
travel quickly southeastward with damaging wind and hail likely.
Some severe activity could potentially push south of the Slight Risk
area into more of northern IL, IN, and Lower MI. However, the
instability gradient will be a limiting factor for eastward extent.
Clusters of storms, possibly forming into a small MCS, are also
expected where very hot temperatures develop into SD. The deeply
mixed boundary layer combined with surface convergence within the
low pressure trough will support afternoon development over eastern
SD, with a corridor of damaging wind potential extending
southeastward into eastern NE and western IA.
...SC and GA...
Daytime heating of a high PWAT air mass will lead to moderate
instability during the afternoon. A surface trough will deepen over
the central Carolinas and into eastern GA, with an uncapped air mass
and weak convergence yielding scattered storms. Shear will be weak,
but modest northwest flow aloft should support corridors of damaging
wind gusts as storms develop southeastward toward the coast.
..Jewell.. 07/25/2026
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