ACUS02 KWNS 261744
SWODY2
SPC AC 261742
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1242 PM CDT Fri Jun 26 2026
Valid 271200Z - 281200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
OF THE NORTHERN HIGH PLAINS...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST
VA AND EASTERN NC...
...SUMMARY...
Severe storms are likely across portions of eastern Montana and
western/central North Dakota on Saturday. Severe storms will also be
possible from the Mid-Mississippi Valley to Virginia and the
Carolinas, as well as portions of the southern High Plains.
...Synopsis...
An upper low and attendant large-scale upper trough will persist
across the western U.S. on Saturday. Further east, upper ridging
over the Plains is forecast to shift east toward the Upper Midwest
and Mid-MS Valley by Sunday morning. Quasi-zonal/weak upper
troughing is expected to persist across the eastern U.S. Within this large-scale regime, several shortwave impulses and embedded MCVs are
expected to drive severe thunderstorm potential across multiple
areas on Saturday. A lead upper shortwave trough is expected to
eject from the eastern Great Basin through the northern High Plains.
A series of MCVs will move from the Ozark Plateau to the OH/TN
Valleys, while another MCV and/or surface trough impacts
thunderstorm potential across the Mid-Atlantic/Piedmont. Finally,
another upper shortwave impulse could emerge across the central
Plains into the Mid-MO/Mid-MS Valleys.
...Northern Rockies into the Northern Plains...
A midlevel jet streak will overspread parts of the Great Basin into
the northern Plains, characterized by 50-60 kt southwesterly 500 mb
flow. Cooling aloft is also forecast and will result in a plume of
steep midlevel lapse rates. Surface low pressure is forecast to
deepen across northeast WY/western SD through evening. This will
support northward transport of low to mid 60s F dewpoints into
eastern MT/ND/SD. This will result in a narrow corridor of moderate
to strong instability. Capping will increase with eastward extent as
a result of midlevel height rises/warming aloft, which should
confine the eastward extent of severe potential.
As large-scale ascent increasing during the afternoon, convection is
expected to develop across the higher terrain of northern UT/ID into
WY. This initial activity will pose a risk for strong wind gusts and
isolated hail given strong deep-layer flow, steep midlevel lapse
rates, and a well mixed boundary layer. Additional convection is
expected to develop near the Big Horns and Beartooth/Absaroka
ranges. As this activity develops northeast into better low-level
moisture and strong instability, large to very large hail potential
will increase. With time during the evening, a southerly low-level
jet will increase across the Dakotas. Upscale growth is possible as
convection moves toward the terminus of the low-level jet and as
sufficient clustering/cold pool development occurs. If this
convective evolution unfolds, a swath of damaging wind gusts will be
possible, mainly across eastern MT into western ND.
...Mid-Atlantic...
Ongoing convection and cloudiness will likely hinder daytime
destabilization. Nevertheless, several shortwave impulses will move
across the region along with 25-30 kt westerly midlevel flow.
Isolated strong storms may produce gusty winds. The Slight risk
(level 2 of 5) has been confined to areas nearer the coast where
instability will be greatest.
...Southern High Plains...
A surface trough/dryline will extend south/southwest from western KS
to southwest TX. A moist airmass will exist east of this boundary
with hot temperatures forecast along and just behind the boundary.
Moderate to strong destabilization will occur near the boundary in a
narrow corridor, confined by stronger capping to the east across
much of OK/KS/central TX. However, isolated to widely scattered
storms are expected to develop during peak heating to early evening.
Vertically veering wind profiles with up to 25 kt effective shear
magnitudes suggest organized updrafts and high-based transient
supercell structures are possible. Given a deeply mixed boundary
layer, strong gusts will be possible. Organized updrafts that can be
maintained also will pose a risk of large hail given very steep
midlevel lapse rates and somewhat elongated hodographs.
...Ozarks to TN Valley vicinity...
Storms are forecast to be ongoing Saturday morning across southwest
MO. This activity could pose a marginal wind/hail risk initially.
Additional development is expected from southern IL/southeast MO
into KY/TN by late morning and spread east through the afternoon as
an MCV moves across the region. While deep layer flow will not be
impressive, the MCV could locally enhanced vertical shear.
Thunderstorm clusters will mainly pose a risk for damaging winds as
they track across moisture-rich and moderately unstable airmass.
...Northeast CO/Western NE into central SD...
Convection may develop during the late afternoon along the surface trough/dryline. Rich boundary layer moisture beneath steep lapse
rates will support strong destabilization. This corridor will remain
rather confined given rising midlevel heights and capping to the
east. Any storms that develop will have potential for strong outflow
gusts and large hail.
...Mid-MO Valley vicinity...
It is uncertain if convection will develop across this area, or if
it does - will it be surface-based, resulting in a rather
conditional severe risk. If storms can develop, an all-hazards
severe risk would be possible given a surface warm front lifting
north across the region amid ample moisture/instability and
supercell wind profiles. Given the conditional nature of the risk,
particularly due to capping, will maintain low severe probabilities.
..Leitman.. 06/26/2026
$$
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