RSS Mesoscale Discussions from Storm Prediction Center
No watches are valid as of Fri Jun 26 09:00:03 UTC 2026.
No Mesoscale Discussions are in effect as of Fri Jun 26 09:00:03 UTC 2026.
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1245 AM CDT Fri Jun 26 2026
Valid 261200Z - 271200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING ACROSS PARTS OF THE OZARKS PLATEAU INTO LOWER OHIO VALLEY
AND ACROSS PARTS OF THE NORTHERN ROCKIES INTO ADJACENT GREAT
PLAINS...
...SUMMARY...
Scattered severe thunderstorm development is possible today,
particularly this afternoon into tonight across parts of the Ozark
Plateau into lower Ohio Valley and across parts of the northern
Rockies into adjacent Great Plains.
...Discussion...
Models indicate that amplification of mid/upper flow across the
eastern mid-latitude Pacific into western North America will
continue through this period, with large-scale troughing and an
embedded cyclonic circulation digging inland across the Pacific
Northwest through Great Basin and northern Rockies, downstream of
building ridging. As this occurs, ridging is likely to build across
the northern Great Plains through upper Mississippi Valley, but
broadly confluent, zonal flow is forecast to persist east of the
mid/upper Mississippi Valley, in the wake of a mid-level trough
accelerating east of the lower Great Lakes through New England and
the Canadian Maritimes. On the southern periphery of this regime, a
number of convectively generated perturbations may progress across
the Ozarks Plateau and lower Ohio Valley through Mid Atlantic today
through tonight.
In lower levels, a weak surface low is forecast to migrate
east-northeast of the lower Great Lakes into northern New England,
before weakening. This may be accompanied by a reinforcing influx
of somewhat cooler and drier area, in the wake of an
ill-defined/diffuse preceding front overspreading the northern Mid
Atlantic. To the west of the Appalachians, this boundary may become
augmented in locations by convective outflow and developing areas of
strengthening differential surface heating during the day. Across
the high plains, fairly significant surface cyclogenesis centered
across southeastern Montana is probable by 12Z Saturday, with
deepening surface troughing southward to the lee of the Rockies.
As a notable plume of very warm elevated mixed-layer air spreads
east of the higher terrain, through much of the Great Plains,
initiation of stronger thunderstorm development may largely be
confined to the higher terrain, before propagating into the
deepening surface troughing across the adjacent plains. Otherwise,
to the east of the Great Plains, forcing for ascent and
destabilization along the weak front, and within low-level warm
advection to the east-southeast of the weak low, may provide support
for at least widely scattered strong to severe storm development.
...Ozark Plateau into lower Ohio Valley...
Higher coverage of potential strong to severe thunderstorm
development may generally focus across this region, aided by at
least a couple of convectively generated perturbations. There is
spread among the various model output, but it still appears that
this could include a fairly notable MCV migrating into the lower
Ohio Valley by around 19-21Z, along a better-defined segment of the
low-level baroclinic zone. With surface dew points forecast near
70F, and a convectively augmented belt of flow on the order of 30-50
kt in the 850-500 mb layer contributing to sufficient shear for
supercell structures, a couple of tornadoes appear possible in a
corridor roughly centered along the Ohio River. Otherwise, several
clusters of thunderstorms may evolve this afternoon and evening,
possibly accompanied by developing corridors of strong to severe
wind gusts.
...Northern Rockies into adjacent Great Plains...
Given a corridor of at least weak to moderate boundary-layer
destabilization near and to the lee of the higher terrain, forcing
for ascent and strengthening vertical shear downstream of the
digging large-scale troughing probably will become supportive of a
period of organized severe thunderstorm development late this
afternoon through evening. This may include supercells and
organizing clusters posing a risk for severe hail and wind, and at
least some potential for a tornado or two.
..Kerr/Chalmers.. 06/26/2026
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Fri Jun 26 2026
Valid 271200Z - 281200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN
MONTANA INTO NORTHWEST SOUTH DAKOTA AND CENTRAL NORTH
DAKOTA...SOUTHEAST VIRGINIA INTO NORTHEAST NORTH CAROLINA...
...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.
...Synopsis...
A broad upper trough will persist in the West. Ridging will build
within the southern/central Plains and Midwest. Multiple MCVs will
impact portions of the Ozarks/Tennessee Valley into the
Mid-Atlantic/Piedmont. A shortwave trough will pivot through parts
of the northern Plains. A surface low near the Black Hills will
deepen and move eastward into Sunday morning.
...Northern Plains...
Within a broader upper trough across the West, a shortwave trough
will pivot northeast through the northern Plains. Surface low
development in eastern Wyoming/the Black Hills vicinity will draw
moisture northward. Effective shear of 40-50 kt will promote initial
supercells capable of large/very-large hail, severe wind gusts and
perhaps a tornado or two. Given the linear forcing within the
surface trough as well as somewhat marginal deep-layer shear suggest
some potential for upscale growth by early evening. As this occurs a
transition to primarily a risk of severe wind gusts (perhaps 75+
mph) will occur. There may be a small corridor of greater severe
gust coverage/intensity, but weaker and potential warm advection
storms to the east decreases confidence in the spatial extent of a
greater wind risk. Even so, some potential for severe gusts and
isolated large hail will continue eastward during the evening along
the nose of a low-level jet in the Dakotas. Farther south into
Nebraska, convective development is more conditional/uncertain. The
environment would support all severe hazards, however.
...Ozarks into Tennessee Valley...
Convection along a surface boundary driven by warm advection appears
probable during the morning hours. This activity is expected to
weaken within the Ozarks and may shift into the Tennessee Valley as
the MCV moves eastward. Damaging winds and marginally severe hail
may occur in Tennessee/Kentucky. Farther west, some airmass recovery
is possible within southern Missouri. A weak MCV emanating from the
southern High Plains may spur convective development during the
afternoon despite modestly rising mid-level heights. A conditionally
favorable environment for a supercell or two will exist. All severe
hazards would be possible if storms can form.
...Ohio Valley into Mid-Atlantic/Piedmont...
Convection may be ongoing in portions of the mid/upper Ohio Valley
during the morning. Some potential for isolated damaging winds may
accompany this activity. Relatively high uncertainty exists as to
how this early-day activity will evolve as it moves eastward during
the day. A weak cold front is forecast to be positioned across parts
of the Mid-Atlantic. South of this boundary, rich surface moisture
will be in place. However, cloud cover may limit destabilization and
weak to modest mid-level lapse rates and weak deep-layer flow will
further limit storm organization potential. Depending on the
timing/location of the Ohio Valley convection/MCV, a narrow zone of
marginally greater shear may promote a more organized threat for
wind damage in southeast Virginia into northeast North Carolina.
Another weakening MCV moving through the Tennessee Valley will
impact the region by late afternoon/early evening, but buoyancy by
that point in the day is more questionable.
...Mid-Missouri into Mid-Mississippi Valley...
With an increase in the low-level jet during the evening, convection
may develop along a boundary draped across the region. Effective
shear and steep mid-level lapse rates would promote some risk for
large hail and isolated damaging winds during the evening into the
overnight. That said, rising mid-level heights may be enough to
inhibit convection from forming altogether.
..Wendt.. 06/26/2026
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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0227 AM CDT Fri Jun 26 2026
Valid 281200Z - 291200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN NORTH
DAKOTA INTO NORTHERN MINNESOTA AND NORTHWEST WISCONSIN...
...SUMMARY...
Severe thunderstorms are possible from the northern Plains into
parts of the Upper Midwest on Sunday. Large hail and severe winds
are the primary hazards.
...Eastern North Dakota into Minnesota...
Some convection is expected to be ongoing during the early morning
in eastern North Dakota. Given the time of day, it is not clear how
intense this activity will be, but some risk for damaging
winds/large hail may exist. With time, a plume of rich surface
moisture and steep mid-level lapse rates will lift northward as the
upper ridge builds in the Midwest. The morning activity may be able
to intensify as is moves into northern Minnesota/northern Wisconsin.
While there remains some uncertainty in the exact evolution, the
Slight Risk has been shifted eastward to account for this potential.
...Northern Plains...
Convection is possible during the late evening as another shortwave
pivots into the High Plains and a surface low deepens in the lee of
the Rockies. The position of this shortwave is not certain. The
ECMWF shows the surface low developing in the central High Plains
while the NAM suggest this will occur farther north into
Nebraska/South Dakota. In either case, steep mid-level lapse rates,
strong deep-layer winds, and adequate buoyancy will support a risk
of large hail and isolated severe gusts during late evening into
parts of the overnight.
...Midwest into Tennessee Valley Vicinity...
Models suggest potential for an MCV to move southeastward through
the day. The position of this feature varies substantially between
models, however, and it will depend on if/how much convection
develops late Saturday night. Marginal severe probabilities may be
needed if confidence on the location of the MCV increases.
..Wendt.. 06/26/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0357 AM CDT Fri Jun 26 2026
Valid 291200Z - 041200Z
...DISCUSSION...
An upper-level trough centered within the Intermountain West will
continue pivoting northeast through the northern Plains on Monday.
This feature will be fairly meridional in character. The strongest
height falls are likely to occur after 00Z within North Dakota. To
the east, an amplified upper ridge will be in place. Moisture
advection will continue in the upper Mississippi Valley given the
southerly low levels winds. Strong to extreme buoyancy is expected
to develop as a result. While this pattern does suggest potential
for severe weather, there is still uncertainty as to where the most
favorable environment will be given the influence of convection that
could occur late on Sunday night into early Monday morning. The 15%
area has been maintained this cycle given the potential for a an MCS
to develop, but modification seems likely in the coming days given
the mesoscale details that will play a large role in where severe
weather ultimately occurs.
From Tuesday onward, the strongest mid-level flow will shift into
Canada as the western upper trough becomes more broad. A large
reservoir of strong to extreme buoyancy is still forecast to be in
place underneath the ridge. While areas of severe weather are
possible, they will be highly tied to mesoscale features as larger
scale features will become more nebulous and deep-layer shear will
weaken through the remainder of the period. As a result,
predictability is reduced.
Read more
SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0300 AM CDT Fri Jun 26 2026
Valid 261200Z - 271200Z
...EXTREMELY CRITICAL FIRE WEATHER AREA FOR CENTRAL UTAH INTO
NORTHWESTERN ARIZONA AND EXTREME SOUTHEASTERN NEVADA...
...CRITICAL FIRE WEATHER AREA FOR MUCH OF UTAH...EASTERN
NEVADA...NORTHERN ARIZONA...SOUTHEASTERN WYOMING...AND FAR WESTERN
COLORADO...
...Synopsis...
Dangerous fire weather conditions are forecast across portions of
the Great Basin and Southwest today as a robust fire weather pattern
begins for an expansive portion of the Intermountain West. This
pattern will bring exceptionally dry and windy conditions following
antecedent dry thunderstorm activity over the past 1-2 days,
resulting in significant fire weather concerns for any new
ignitions, lingering holdovers, and ongoing large fires across the
western CONUS.
...Northwestern Arizona and far southeastern Nevada into central
Utah...
A seasonably strong mid-level trough will dig into the western CONUS
today, with an attendant mid-level jet overspreading portions of the
Great Basin as upper-level ridging amplifies over the Great Plains.
This will promote a deepening surface cyclone over the northern
Great Basin, which will subsequently support a strong surface
pressure gradient across much of the Intermountain West when
combined with surface high pressure over New Mexico. Latest high-res
guidance continues to depict a corridor of strong southwesterly
winds (sustained 25-35 mph) developing amid very low RH values of
5-15% from far southeastern Nevada and northwestern Arizona into
central Utah. With very dry and receptive fuels across this region
(ERCs in the 80-90+ percentiles) and ongoing large wildfire
activity, these conditions will yield an extremely critical fire
weather threat across this region. Deep boundary layer mixing
coupled with the aforementioned mid-level jet will also promote wind
gusts to 45 mph. A more expansive area of elevated to critical fire
weather concerns is expected across adjacent areas of the Great
Basin where modestly weaker sustained surface winds (generally 15-25
mph) are forecast to overlap very low RH values of 5-20%. An
extended period of critical wind/RH conditions (perhaps 10+ hours
for some locations), poor overnight humidity recoveries, and
residual gusty winds are forecast. Only minor adjustments were made
to the drawn areas with this update to reflect the latest available
guidance, and minor trimming was done on the northeastern extent of
the Elevated highlights in central Wyoming to account for heavier
rainfall on Thursday.
...Colorado Plateau...
Increasing mid-level flow and ascent ahead of the approaching
mid-level trough (coupled with dry boundary layer profiles and PWAT
values of 0.5-0.8") will support the potential for isolated dry
thunderstorms this afternoon from northwestern New Mexico into much
of western Colorado. While storm motions are anticipated to be
generally 20-30+ kts, pockets of heavier rainfall totals are
possible, especially across northwestern New Mexico and southwestern
Colorado where the latest guidance suggests PWAT contents and storm
coverage may be locally greater. Thus, a mix of wet/dry
thunderstorms is likely. Pockets of lingering receptive fuels (ERCs
in the 80-90+ percentile) will continue to be receptive to lightning
ignitions, however, and concerns regarding any lightning ignitions
increase as multiple days of critical fire weather conditions are
expected this weekend.
..Chalmers.. 06/26/2026
...Please see www.spc.noaa.gov/fire for graphic product...
Read more
SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
0302 AM CDT Fri Jun 26 2026
Valid 271200Z - 281200Z
...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF EASTERN
NEVADA...NORTHERN ARIZONA...NORTHWESTERN NEW
MEXICO...SOUTHERN/CENTRAL UTAH...SOUTHERN WYOMING...AND WESTERN
COLORADO...
...Synopsis...
A seasonably strong mid-level trough will continue to dig into the
western CONUS on D2/Saturday, with an attendant mid-level jet
overspreading much of the Upper Colorado River Basin. This will
continue to support a robust fire weather pattern across an
expansive portion of the Great Basin and Southwest through the
weekend.
...Great Basin/Southwest...
As the mid-level jet associated with the digging mid-level trough
shifts eastward into the Upper Colorado River Valley, a corridor of
stronger, sustained surface winds (25-30 mph) will expand from
southeastern Nevada into the Colorado Plateau and overlap with very
low RH values of 10-15%. Exacerbated by dry, windy conditions on
D1/Friday, fuels will be very receptive, with ERCs already noted in
the 80-90+ percentiles. These conditions will promote an extended
period of critical fire weather conditions from southeastern Nevada
into the Upper Colorado River Basin and southern Wyoming. Localized
extremely critical wind/RH conditions are possible, particularly
across southeastern Utah and perhaps into southwestern Colorado
where latest high-res guidance suggests that the best overlap of
sustained southwesterly winds approaching 30 mph and very low RH
near 10% may occur. Pockets of fuels in this region are also noted
to be at or above the 95th percentile. A broader area of elevated
wind/RH conditions are expected across adjacent areas of the Great
Basin/Southwest where sustained winds of 15-25 mph are forecast to
overlap dry fuels and RH values of 10-20%.
The primary change with this outlook was to expand the Critical
highlights into north central Colorado based on the latest high-res
guidance. Consideration was given to the addition of a targeted
Extremely Critical area; however, some uncertainty remains regarding
the duration of overlap between sustained winds exceeding 30 mph and
RH values dropping below 10%. A portion of the Elevated highlights
were also trimmed across central Wyoming and the foothills of
northern Colorado owing to recent rainfall.
..Chalmers.. 06/26/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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