RSS Mesoscale Discussions from Storm Prediction Center
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Thu Jun 25 2026
Valid 251200Z - 261200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
INTO TONIGHT ACROSS PARTS OF THE SOUTHERN AND CENTRAL GREAT
PLAINS...
...SUMMARY...
One or two organizing clusters of storms, with potential to produce
strong to severe wind gusts, are possible across parts of the Texas
South Plains through central Great Plains late this afternoon into
tonight. Isolated strong storm development preceding this activity
across parts of north central Oklahoma into south central Kansas may
pose a risk for a couple of tornadoes by early this evening.
...Discussion...
The westerlies are undergoing amplification across the mid-latitude
Pacific. Later today into tonight, models indicate that this will
include digging large-scale mid-level troughing on its leading edge,
across and inland of the Pacific Northwest coast. Downstream, it
appears that generally zonal flow will prevail across the northern
and central tier of the U.S., to the north of ridging in the
subtropical latitudes. Within this regime, mid-level troughing,
accompanied by an area of modest height falls within otherwise
rising heights, is forecast to turn eastward across the lower Great
Lakes vicinity. Upstream, initially stronger mid-level height falls
accompanying a short wave perturbation, and perhaps a notable
embedded mesoscale convective vortex, may be in the process of
overspreading the central Great Plains at the outset of the period,
before continuing toward the lower Missouri Valley, amidst weak to
modest larger-scale height rises late this afternoon through
tonight.
In lower levels, a broad weak surface low is forecast to migrate
across the lower Great Lakes, with a an ill-defined trailing influx
of cooler/drier air advancing a bit farther southward through the
central Great Plains, and southeast of the Upper Midwest through the
Great Lakes and adjacent portions of the Ohio Valley. It appears
that surface troughing will deepen through the day to the lee of the
southern Rockies, as strong heating occurs beneath a remnant plume
of very warm elevated mixed-layer air across the southern Great
Plains. Near the northern/northeastern periphery of this air mass,
a zone of strong differential heating may develop by late afternoon,
northeast of the Raton ridge into northern Oklahoma. This boundary
might be augmented by outflow from a cluster of storms now evolving
across northeastern Colorado into western Kansas. It appears that
this boundary may retreat northward into portions of southern Kansas
and Missouri tonight.
...Parts of southern/central Great Plains...
The potential convective evolution for today remains unclear, and
severe weather potential will considerably be impacted by
sub-synoptic developments, which remain unclear. This includes the
subsequent evolution of the cluster of storms now propagating into
northwestern Kansas, and another forming across the Texas Panhandle
vicinity. However, guidance generally suggests that low-level
convergence and destabilization within the lee surface trough across
the Panhandle vicinity into Texas South Plains may provide support
for widespread thunderstorm development by early this evening. And
the boundary across the central Great Plans, reinforced by early day
outflow and subsequent differential heating, may eventually become a
focus for increasing thunderstorm development this evening into the
overnight hours.
A deeply mixed boundary layer across the Panhandle/South Plains
vicinity may become unstable enough to support the risk for large
hail, in addition to damaging wind gusts late this afternoon into
evening.
Low-level convergence/warm advection along the zone of differential
surface heating might promote at least isolated supercell
development somewhere across north central Oklahoma into south
central Kansas, where a convectively augmented belt of westerly
mid-level flow may contribute to strong shear. If this occurs, this
may be accompanied by a period of increasing potential for a tornado
or two by early evening, near the nose of a strengthening southerly
850 mb jet, before evolving into an upscale growing cluster with
strong surface gusts becoming the primary potential hazard
overnight.
...Lower Great Lakes...
Convection allowing model output is still not providing a clear
signal for more than rather isolated pre-frontal strong to severe
thunderstorm development. However, strengthening westerly flow in
the 700-500 mb layer could become sufficient to support organized
convective development, including supercells, with sufficient
destabilization. Depending on model trends, it is still possible
that probabilities could be increased in later outlooks for this
period.
...Parts of central and southern Wyoming...
Latest convection allowing guidance suggests that thermodynamic
profiles by this afternoon could become conducive to the evolution
of an organizing cluster of storms with potential to produce strong
to severe surface gusts, aided by forcing for ascent associated with
a short wave perturbation emerging from the northern intermountain
region.
..Kerr/Chalmers.. 06/25/2026
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1235 AM CDT Thu Jun 25 2026
Valid 261200Z - 271200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE HIGH
PLAINS AND EASTWARD ACROSS SOUTHERN KANSAS AND NORTHERN OKLAHOMA TO
THE OHIO VALLEY...
...SUMMARY...
Isolated severe storms capable of large hail and severe wind gusts
will be possible across the High Plains, southern Kansas and
northern Oklahoma, and into the Ohio Valley on Friday. Additional
severe storms capable of damaging wind and isolated large hail will
also be possible across portions of the Northeast.
...Synopsis...
A mid-level trough will amplify across the Northwest CONUS on Friday
as ridging builds across the Plains. A broad surface low will exist
from northwest Texas into Missouri along a frontal zone. A lee
cyclone will develop across the northern High Plains as the primary
trough starts to eject over the northern Rockies. This will result
in strengthening southerly flow across the Plains and
destabilization from eastern Colorado into eastern Wyoming and
perhaps far southeast Montana.
...High Plains...
Weak to moderate destabilization is forecast across the High Plains
as dewpoints increase into the 60s during the afternoon. Slight
height rises may limit storm coverage somewhat, but as storms form
across the terrain Friday afternoon/evening, the environment
downstream should support these storms continuing. Some storm
organization and transient rotating updrafts are possible from
northeast Colorado into eastern Wyoming, but only modest effective
shear (around 25 knots) should limit overall storm intensity
somewhat. Nonetheless, some large hail and severe wind threat is
possible.
...Central/southern Plains to the Ohio Valley...
Storms will likely be ongoing at the beginning of the period across
Missouri and into southern Illinois and Indiana. These storms should
weaken as the move east of the greatest instability by late morning.
In the wake of this activity, moderate to strong destabilization is
expected. This should prove sufficient for isolated to scattered
storm development along the remnant frontal zone/outflow boundary
during the afternoon/evening. Most guidance shows 35 to 40 knot
mid-level flow remaining across the region which should be
sufficient for supercell organization. In addition, a vorticity rich
environment will likely be present in the wake of morning storms. If
sufficient destabilization can occur within this airmass, some
tornado threat may exist.
Most notably, the NAM shows a more volatile scenario with a stronger
mid-level shortwave trough and a more defined surface low moving
along the boundary. This scenario appears to be a clear outlier
among 00Z guidance. However, it does represent the ceiling of this
potential scenario. While a marginal hail/wind/isolated tornado
threat seems like the most likely scenario, guidance will be
monitored closely for any hint of this more intense NAM solution.
...Northeast...
A line of storms will move through the Northeast Friday morning. In
the wake of these storms, some destabilization is expected ahead of
a cold front moving through the area. There is some uncertainty
about the degree of destabilization, but at least weak instability
is shown by most guidance. A strong mid-level jet streak across the
region (50+ knots) will provide long/straight hodographs. This will
support the potential for isolated large hail and damaging wind
gusts with the strongest storms.
..Bentley.. 06/25/2026
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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0215 AM CDT Thu Jun 25 2026
Valid 271200Z - 281200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
THE NORTHERN PLAINS....
...SUMMARY...
Severe storms are likely across portions of eastern Montana and
western North Dakota on Saturday. More isolated strong to severe
storms are possible from the Mid-Mississippi Valley to Virginia and
the Carolinas.
...Synopsis...
On Saturday, the leading edge of a larger mid-level shortwave trough
will eject across the northern Plains. A surface lee cyclone will
develop in this vicinity. Farther east, a weak surface low is
forecast to move from the Ohio Valley to the East Coast, weakening
through the period.
...Northern Plains...
Low-level southerly flow will strengthen through the day Saturday
within the warm sector of a lee cyclone across the Plains. This will
lead to destabilization and moderate to strong instability by
mid-afternoon Saturday. Storms will initially form across parts of
central and eastern Montana, and will likely grow upscale into a MCS
as it moves northeast through the evening.
Additionally, there is some supercell threat east of this activity
during the afternoon/evening. This is a more conditional threat, but
the environment would support tornadoes and very large hail if more
isolated storms form. For now, the 15% probabilities cover the most
likely region for a severe wind threat from a MCS, with some area
farther east included for the conditional supercell threat.
...Mid-Mississippi Valley to the Carolinas and Virginia...
Moderate to strong instability is forecast along and south of a
frontal zone from the Mid-Mississippi Valley to the Carolinas on
Saturday afternoon. Forecast soundings show weak shear across this
zone, but at least moderately steep mid-level lase rates and
moderate instability may support some damaging winds Saturday
afternoon/evening. Slightly greater damaging wind potential may
exist across Virginia into North Carolina along an eastward
advancing cold front where moderate to strong instability is
forecast beneath a mid-level shortwave trough and associated
slightly stronger flow.
..Bentley.. 06/25/2026
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