RSS Mesoscale Discussions from Storm Prediction Center
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1256 AM CDT Wed Jun 03 2026
Valid 031200Z - 041200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
THE EASTERN DAKOTAS INTO WESTERN MINNESOTA...
...SUMMARY...
Thunderstorms with large to very large hail and severe wind gusts
will be possible Wednesday afternoon into night in parts of the
northern Plains into upper Mississippi Valley. More sporadic
occurrences of large hail and severe wind gusts appear possible
across parts of the central High Plains and southwest Texas into
southeast New Mexico.
...Synopsis...
The upper low will move into the Canadian Prairie today. A modest
mid-level jet will overspread North Dakota into northern South
Dakota. A cold front will move south and east through the Dakotas. A
surface high in the Great Lakes region will promote moisture
advection into the High Plains.
...Northern Plains...
A modest low-level jet (45 kt at KLNX) is promoting a small cluster
of convection along the Nebraska/South Dakota border early this
morning. The duration of this activity is not certain, but it is
possible that it could last until daybreak when the low-level jet is
forecast to weaken. At a minimum, cloud cover from this activity may
delay heating in some areas. Models still bring low 60s F dewpoints
into South Dakota by the afternoon. Forcing for ascent will be
strongest in North Dakota where the upper low will be. Modest ascent
will still occur into South Dakota along the surface trough/front.
40-50 kt of shear will promote organized supercells, at least
initially. There does appear to be a small corridor where a discrete
mode could be maintained longer where the shear vectors will be more
orthogonal the surface trough. There, very-large hail would be more
probable. Overall, a transition to a linear mode is expected to
occur within a couple of hours of initiation as the front moves
southeast. Severe winds would become more likely as this occurs. The
tornado threat will be greatest with the initial discrete storms.
The low-level jet does modestly increase during the evening when a
linear mode should dominate. A QLCS circulation or two is possible,
but the wind threat should be the main concern.
...Central into southern Plains...
Weak convectively generated MCVs are apparent in water vapor imagery
in the Southwest. As these move slowly eastward into this
afternoon, perhaps congealing, they will interact with a surface
trough/stalled boundary in the High Plains. Deep-layer winds will
otherwise be weak, but the MCV may locally enhance shear. Low to mid
60s F dewpoints will contribute to 1500-2000 J/kg despite fairly
modest mid-level lapse rates. The strongest storms will be capable
of isolated large hail and severe gusts. Some clustering may occur
which would locally increase the threat for strong/severe winds.
...Southwest Texas...
Early morning convection appears possible within the region. The
spatial extent/intensity of this activity will play a large role in
whether stronger convection can develop later in the afternoon/early
evening. Should cloud cover/outflow influence be minimal, strong
heating southwest of the region along with moist influx from the
southeast will promote thunderstorms within the Davis Mountains/Big
Bend. Deep-layer flow will only be modest, but isolated large hail
and severe gusts would be possible.
..Wendt/Moore.. 06/03/2026
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1230 AM CDT Wed Jun 03 2026
Valid 041200Z - 051200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE
NORTHERN HIGH PLAINS ACROSS SOUTH DAKOTA AND NORTHERN NEBRASKA INTO
SOUTHWEST MINNESOTA...
...SUMMARY...
Severe thunderstorms capable of large to very hail and damaging
winds are possible from parts of the northern High Plains into lower
elevations of the northern and central Plains Thursday afternoon
into night. More isolated occurrences of large hail and damaging
winds appear possible in parts of the upper Midwest and upper Great
Lakes.
...Synopsis...
A low-amplitude, cyclonic flow regime will be maintained across the
north-central U.S. with several embedded disturbances moving through
that airflow pattern. At the surface, a cold front is forecast to
move from the upper MS Valley into the upper Great Lakes with that
boundary trailing southwest through the mid MO Valley to eastern WY,
where it will link with a lee cyclone. A dryline/lee trough will
extend south from the low pressure through the central and southern
High Plains.
...Northern and Central Plains...
A short-wave trough embedded in the cyclonic flow initially over the
northern Rockies Thursday morning will shift into the northern High
Plains by afternoon. Strengthening mid-level winds and forcing for
ascent downstream from that feature will progressively overspread a
moist and moderately unstable (MLCAPE 1000-1500 J/kg) upslope regime
present across portions of southeast MT, northeast WY, and western
SD, to the north of the surface boundary. Those processes will
contribute to initial storm development in those areas by mid
afternoon with the kinematic environment favoring supercells capable
of large to very large hail and perhaps a tornado or two.
Additional storm development will be possible farther east along the
front in central/eastern SD and northern NE amidst a moderately
unstable environment (MLCAPE of 1500-2000 J/kg) with weakening
vertical shear and mid-level lapse rates with eastward extent. As
such, a mix of multi-cell and some supercell structures appear
possible with an associated risk for large hail and severe wind
gusts.
Those two separate regimes may consolidate into one or more MCSs
Thursday evening/night, with a continued risk for damaging winds and
sporadic large hail.
Elsewhere, diurnally enhanced storms will be possible south along
the lee trough into northeast CO, as well as ahead of a sheared
vorticity maximum moving through portions of northeast KS, eastern
NE, and IA. Steep lapse rates and around 30 kt of deep-layer shear
may support isolated, high-based storms in the former area with some
wind and hail threat. Poorer mid-level lapse rates and weaker
vertical shear expected in the latter areas would limit
severe-weather potential to mainly wet microburst activity. Model
soundings do show some low-level hodograph curvature, so a brief
tornado cannot be ruled out.
...Upper Midwest/Upper Great Lakes...
Relatively poor mid-level lapse rates are forecast across the
pre-frontal warm sector Thursday; however the presence of
boundary-layer dewpoints in the low to mid 60s will largely
contribute to a narrow axis of MLCAPE up to 1000-1500 J/kg by
afternoon. The glancing influence of a mid-level low moving into the
northwest Ontario coupled with convergence along the front are
expected to foster widely scattered thunderstorms by mid to late
afternoon.
The presence of 30-40 kt of deep-layer shear will be sufficient for
multi-cells and transient supercell structures capable of locally
damaging wind gusts and perhaps marginally severe hail. Modest
strengthening of the low-level jet is noted across northern WI into
the western UP of MI late Thursday afternoon into evening, which
could yield sufficient low-level shear for some tornado risk. No
probabilities will be included in this forecast due to uncertainty
in the degree of instability in those areas.
..Mead.. 06/03/2026
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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0348 AM CDT Wed Jun 03 2026
Valid 051200Z - 061200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL AND
EASTERN NEBRASKA INTO IOWA...SOUTHERN MINNESOTA...AND WESTERN
WISCONSIN...
CORRECTED FOR ERRONEOUS GEOGRAPHICAL REFERENCE
...SUMMARY...
Scattered severe storms capable of large to very large hail,
damaging winds, and perhaps a couple of tornadoes are expected
Friday afternoon into night across portions of the upper Midwest
into central Plains.
...Synopsis...
The primary upper-air feature of interest Friday is a short-wave
trough, which is forecast to amplify while progressing from the
northern Plains into the upper MS Valley and upper Midwest. A cold
front associated with at upper-air system is expected to stretch
from the upper Midwest through the mid MO Valley into the central
High Plains by mid afternoon. That boundary is expected to serve as
the focus for strong to severe thunderstorm development from
afternoon into Friday night.
...Upper Midwest into the Central Plains...
Areas of thunderstorms may be ongoing Friday morning across parts of
the Midwest and possibly northern Plains, with that activity
expected to decrease in areal coverage through the morning. However,
residual cloudiness and convective outflow may slow the
destabilization process in areas where the storms linger the
longest. Outside of those areas, model guidance indicates the
development of moderate to strong instability within the pre-frontal
warm sector by mid to late afternoon.
Height falls/forcing for ascent associated with the migratory
short-wave trough coupled with low-level convergence along the
synoptic front and any remnant outflow boundaries are expected to
contribute to an areal increase in storms during the afternoon and
evening hours. An associated risk for at least isolated severe
weather appears possible in parts of the northern and central Plains
into the upper Midwest and upper Great Lakes region. Within that
broader envelope, a potentially more concentrated zone of severe
storms may materialize in the vicinity of the synoptic front from
parts of western WI and southern MN into central and eastern NE.
There, a favorable overlap of 30-40 kt of deep-layer shear and the
moderate to strong instability is forecast to develop, supporting
organized storm modes capable of mainly large to very large hail and
damaging wind gusts. Some increase in low-level shear is forecast
across the mid MO Valley Friday evening, conditionally supporting
some tornado risk.
..Mead.. 06/03/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0345 AM CDT Wed Jun 03 2026
Valid 061200Z - 111200Z
...DISCUSSION...
...Day 4/Saturday...
Model guidance is in good agreement in the progression of a
short-wave trough from the Great Lakes into Northeast, with a strong
upstream system moving through the Canada Rockies and Pacific
Northwest into the northern Rockies. Elsewhere, a mid-level low will
track through the southern and central Plains. In the low levels, a
cold front is forecast to move through the Great Lakes into the OH
Valley and Northeast, while a lee cyclone deepens over the northern
High Plains along a separate cold front emerging from the northern
Rockies.
The most probable location for organized severe thunderstorm
development appears to be in the vicinity of the lee cyclone and
front in portions of eastern MT and western ND Saturday afternoon
and evening. There, steep lapse rates and moderate instability will
coincide with steadily strengthening deep-layer shear. Elsewhere, at
least isolated severe storms appear possible along the cold front
from portions of the Great Lakes into the OH Valley and the
Northeast, as well as in parts of TX, to the southeast of the upper
low.
...Day5/Sunday...
A short-wave trough will continue through the Northeast and
Mid-Atlantic, while the bulk of ensemble guidance suggests the
northern Rockies disturbance will lift northeast into the Canadian
Prairie Provinces. Meanwhile, the central/southern Plains low is
forecast to evolve into an open wave while moving into the mid/lower
MO Valley and Ozark Plateau. The models indicate the potential for
moderate to strong instability to develop across the northern Plains
warm sector on Sunday afternoon. However, there is some signal that
the strongest vertical shear will be displaced to the west of the
cold front. Furthermore, given that the strongest forcing for ascent
is expected to lift north of the International Border, residual
capping across the warm sector may limit storm coverage. Given these
concerns, no probabilities will be included in this forecast.
Elsewhere, at least isolated severe storms appears possible along
the cold front in portions of the Northeast into Mid-Atlantic Sunday
afternoon.
...Day 6-8/Monday through Wednesday...
Ensemble guidance is suggestive that mid-level troughing will evolve
along the West Coast early next week, with that feature slowly
advancing through the Interior West. Considerably more spread is
evident in the deterministic models, with low confidence in any one
solution. In general, it appears that the stronger mid-level flow
associated with the western U.S. trough may begin to overspread
portions of the northern and central High Plains by Tuesday and/or
Wednesday, where a moist and unstable air mass is expected to
reside. Should confidence increase in the finer-scale details of the
pattern, unconditional 15% probabilities may need to be included
during this time frame.
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