RSS Mesoscale Discussions from Storm Prediction Center
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0703 AM CDT Mon Jun 08 2026
Valid 081300Z - 091200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING FROM NORTHEAST COLORADO AND SOUTHEAST WYOMING INTO PARTS OF
NEBRASKA AND KANSAS....
...SUMMARY...
Scattered thunderstorms with large to very large hail, severe wind
gusts potentially above 70 mph, and a few tornadoes will be possible
today from the Front Range east-southeastward into the central
Plains. Isolated severe gusts and hail will also be possible in
parts of the southern High Plains, northern Plains and mid
Mississippi Valley. An isolated hail threat may develop toward the
end of the period in the northern High Plains.
...Eastern CO into Western NE/KS...
Relatively fast southwest flow aloft is present today from the
southwest states into the central Rockies. A surface low will
remain over southwest KS through the day, maintaining a stream of
easterly low-level winds and moist advection into eastern CO and
northwest KS. Daytime heating will further aid the westward
transport of moisture, resulting in an unstable air mass over the
foothills near Denver/CO Springs. Thunderstorms are expected to
develop in this corridor this afternoon, in an environment of steep
mid-level lapse rates, CAPE around 1000 J/kg, and favorable
deep-layer shear. Supercell structures capable of large hail will
be the main early threat. As this activity moves/builds eastward
into the Plains, it will encounter increasingly moist/unstable air
and strengthening low-level shear profiles by early evening. This
will promote a risk of a few supercell tornadoes, large hail, and
damaging winds. An upgrade to ENH risk may be needed in later
updates as clouds/daytime heating and affects of ongoing NE
convection is assessed.
By mid-evening, the activity is expected to be organizing upscale
into linear structures as it moves into southwest NE and northwest
KS. An increasing risk of damaging winds will likely develop, with
storms spreading eastward into the overnight hours.
...Northwest AR...
A cluster of intense thunderstorms is ongoing this morning over
southwest MO/northeast OK. This activity could continue to pose a
risk of isolated damaging wind gusts through the morning into
northwest AR before weakening later today.
...Southern KS/Northwest OK/TX Panhandle...
A dryline will become established this afternoon from the eastern TX
Panhandle to the surface low in south-central KS. Hot conditions
along/west of the dryline will help to initiate isolated
thunderstorms. These high-based cells could pose an occasional
threat of hail and damaging winds for a few hours.
...Eastern KS...
A moist and very unstable air mass will lie across eastern KS today
with CAPE values of 3000-4000 J/kg, but with a weak cap. CAM
guidance varies on the potential for afternoon/early evening
thunderstorms in this area, but enough 00z runs suggested a threat
to maintain the SLGT. Any storm that can form would pose a risk of
large hail and damaging winds.
...Southern IL/Western KY...
An upper trough continues to lift northeastward across the mid MS
valley today, with a moist/moderately unstable air mass present from
southern IL southward. Mid-level lapse rates are marginal for
severe storms, and winds aloft are modest. Nevertheless, veering
winds-with-height and sufficient CAPE will pose an occasional risk
of strong storms capable of gusty winds or a tornado today.
..Hart/Wendt.. 06/08/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0345 AM CDT Mon Jun 08 2026
Valid 111200Z - 161200Z
...DISCUSSION...
...Day 4/Thursday...
An active period of severe weather is expected from the upper Great
Lakes into Ozark Plateau, with the most concentrated and potentially
most significant severe storms affecting parts of the Midwest.
Within the base of an upper low centered over Manitoba and northwest
Ontario, the models are in good agreement in depicting the
progression of a potent short-wave trough and attending
mid/upper-level jet streaks through the upper Midwest and upper
Great Lakes. There is some model signal that a trailing perturbation
on the immediate cyclonic side of the mid-level jet will overspread
the mid MS Valley Thursday night.
At the surface, a deepening surface low/frontal wave is expected to
develop from central IA into the southern UP of MI during the day,
along a cold front advancing through the upper Midwest and into the
upper Great Lakes. The southwest extension of that boundary will
progress southeast through the lower MO and Mid MS Valleys, while
becoming quasi-stationary across the southern Plains. The specific
boundary location across the Midwest may be modified to some extent
from a thunderstorm complex moving through the area Wednesday
night/early Thursday.
A very moist air mass is expected to reside to the south of the
surface front, which coupled with modestly steep mid-level lapse
rates is expected to yield moderate to strong instability. The
presence of a 50-70 kt mid-level jet streak attending the short-wave
trough will result in relatively strong deep-layer shear along the
frontal zone, with vector orientation becoming increasingly parallel
to the boundary with southward extent. The overall pattern appears
supportive of an organized severe-weather episode from the upper
Great Lakes into mid MS Valley. There is some model signal that a
corridor of enhanced tornado potential could develop along and south
of the surface low track from eastern IA and northern IL into
central and southern WI. That potential scenario will be dictated by
the location of the effective surface boundary.
Additional, more isolated severe storms appear possible across parts
of the Northeast.
...Day 5/Friday...
A number of the 00z models progress a lower-latitude short-wave
trough through the upper OH Valley and lower Great Lakes, which is a
departure from previous model runs. That scenario would increase
severe-weather potential across those areas into New England, and
perhaps the Mid-Atlantic, given the potential for a moderately
unstable air mass across the pre-frontal warm sector. Should
subsequent model runs remain consistent with this recent trend, an
unconditional 15% probability contour may be needed in the next
forecast update.
Elsewhere, Isolated severe storms appear possible across portions of
the southern High Plains.
...Day 6/Saturday...
The ensemble mean solutions are in good agreement in depicting a
mid/upper-level low over Hudson Bay with a belt of strong mid-level
flow extending from slight troughing over the northern High Plains
into the Great Lakes and Northeast. There is more spread across the
deterministic models with respect to the longitudinal position of
that trough, and the position of the associated frontal system. In
general, it appears some severe weather threat could materialize
across the central Plains. However, confidence in that scenario is
low.
...Days 7 and 8/Sunday and Monday...
The ensembles indicate a gradual amplification of the large-scale
pattern, featuring troughing from Hudson Bay into the MS Valley, and
upstream ridging across western Canada and the Pacific Northwest.
The location of any relevant surface frontal systems remains highly
uncertain, as does the location(s) of any severe-weather threat.
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