SPC Jul 26, 2026 1630 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... 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 Jul 26, 2026 1300 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... 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


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SPC Jul 26, 2026 0100 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 0100Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0800 PM CDT Sat Jul 25 2026

Valid 260100Z - 261200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR EASTERN
SD...SOUTHWEST MN...NORTHERN IA...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF
CENTRAL/EASTERN MT...

...SUMMARY...
Severe gusts (potentially greater than 75 mph) remain possible this
evening from eastern South Dakota into northern Iowa and southwest
Minnesota. Isolated to widely scattered severe gusts also remain
possible across parts of Montana.

...SD into southern MN/northern IA/far northeast NE...
A loosely organized storm cluster is moving across eastern SD this
evening. Additional intensification remains possible this evening,
as this cluster encounters extreme downstream buoyancy, with MLCAPE
of 4000-5000 J/kg within a very moist (dewpoints around 80 F)
environment. The ongoing cluster has produced measured gusts of
60-80 mph, so any notable intensification could lead to an increase
in potential for gusts in the 75-90 mph range. Isolated hail and
perhaps a tornado also remain possible through dusk with this
cluster. Increasing CINH with time and eastward extent should
eventually result in a weakening trend later tonight, though an
organized severe threat could eventually approach parts of southeast
MN/northeast IA into northwest IL overnight.

Farther northwest, a separate storm cluster is moving across
north-central SD, within a similarly favorable environment. In the
short term, this cluster may continue to move east-southeastward
along a surface boundary with a continued severe-wind threat.
Eventually, weakening buoyancy in the wake of the southeast SD
cluster will tend to result in a weakening trend with this cluster.

...Central/eastern Montana...
Strong to locally severe storms may persist through dusk across
parts of central/eastern MT, within a well-mixed environment that is
favorable for severe-wind potential. Increasing CINH will result in
an eventual weakening trend later tonight, though remnant outflows
may still produce strong to locally severe gusts as storms diminish.

...Southern AZ...
Widely scattered storms and increasing outflow may continue to
support strong to localized severe gusts within a very hot and
well-mixed environment across parts of southern AZ. Weak deep-layer
flow/shear should keep any remaining threat generally disorganized.

..Dean.. 07/26/2026


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SPC Jul 25, 2026 2000 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 2000Z Day 1 Outlook


Day 1 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0307 PM CDT Sat Jul 25 2026

Valid 252000Z - 261200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL
AND EASTERN SOUTH DAKOTA...INTO SOUTHWESTER MINNESOTA AND NORTHWEST
IOWA...

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
CENTRAL MONTANA...

CORRECTED FOR MISSPELLING

...SUMMARY...
Widespread severe gusts are possible across South Dakota late this
afternoon and into portions of southwestern Minnesota and northwest
Iowa through the evening.

...20 Update Northern Plains/Midwest...
Confidence continues to increase in widespread severe gusts
developing across parts of central and eastern SD late this
afternoon and into the evening. Very hot surface temperatures
(100-110F) are supporting very steep-low and mid-level lapse rates
of 8-9 C/km over western SD. Initial storms developing now with
temperature-dew point spreads of 40-50 F will favor efficient
outflow generation and an increasing potential for severe gusts as
convection develops and intensifies this afternoon.

The primary severe concern across the northern Plains and Midwest
remains the potential for widespread severe wind gusts with one or
more organized convective clusters. A CIG-2 wind area was added for
the potential for some peak gusts in the 80-100 mph range. Some
recent CAM guidance has trended toward more clustering and a compact
bowing cluster across central and eastern SD late this afternoon and
evening. A brief mesovortex tornado or two may also occur if a
bowing cluster can develop. However, weaker overall synoptic forcing
suggests lower confidence in how widespread the most intense storms
will be. See MCD#1729 for short-term information.

Downstream, wind probabilities and CIG-1 have been expanded along a
surface wind shift/buoyancy gradient into parts of northeast NE, IA
and southern MN. Recent HRRR/RRFS time-lagged runs continue to show
a strong cluster moving east and then southeastward this evening and
into the overnight hours. Strong to severe gusts will remain
possible with these storms given the large buoyancy.

Farther north across MN, isolated storms, including supercell
structures could support isolated hail or damaging gusts this
evening.

...MT...
Scattered to widespread high-based storms remain likely this
afternoon and evening over central and southern MT. Steep-lapse
rates in the lowest 3-5 km will support a risk for severe gusts.
Some clustering may occur as storms spread eastward into this
evening. No changes were made to the outlook, see the prior
discussion.

..Lyons.. 07/25/2026

.PREV DISCUSSION... /ISSUED 1137 AM CDT Sat Jul 25 2026/

...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.


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