Day 3 Convective Outlook  
NWS Storm Prediction Center Norman OK
0227 AM CDT Tue Jun 02 2026

Valid 041200Z - 051200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN HIGH PLAINS...MUCH OF SOUTH DAKOTA...AND NORTHERN
NEBRASKA...

...SUMMARY...
Severe thunderstorms capable of large 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 mid/upper-level low over southern Manitoba Thursday morning is
forecast to move into Ontario ahead of a weakening short-wave trough
translating from the northern Rockies into northern Plains. A
separate disturbance is expected to progress through the central
Plains. In the low levels, a surface low will track from southern
Manitoba into northwest Ontario while a trailing cold front advances
through the upper MS Valley into the upper Great Lakes. The trailing
extension of the boundary will link with a surface low over eastern
WY.

...Northern High Plains into the upper Great Lakes...

The synoptic front and low-level upslope flow north of the boundary
in the northern High Plains will be the main foci for strong to
severe thunderstorm development Thursday afternoon into night. The
most favorable overlap of steep lapse rates, moderate instability,
and modestly strong vertical shear is expected to reside in those
same areas from the northern High Plains east into the mid MO
Valley.

Aided by forcing for ascent associated with weakening short-wave
trough, diurnally enhanced thunderstorm development is anticipated
Thursday afternoon from portions of eastern MT into western SD, near
and to the north of the stalled surface front. The environment
appears supportive of supercell storm modes capable of large to very
large hail initially, especially across western SD. Some model
guidance suggests that the initial discrete storms may grow upscale
into a forward-propagating MCS that would advance east across SD
Thursday night with an associated risk for severe wind gusts.

A potentially separate strong to severe storm regime may materialize
Thursday afternoon and evening across portions of central and
eastern NE into western IA in association with the lower-latitude
disturbance moving through those areas. Vertical shear will be
weaker than locations farther to the northwest; however, the
presence of a moderately unstable air mass may support isolated
occurrences of large hail and severe wind gusts.

Isolated to widely scattered, strong to severe storms may also
develop along the cold front across parts of the upper Great Lakes
into upper Midwest Thursday afternoon and evening with an associated
damaging wind and/or large hail risk.

..Mead.. 06/02/2026

Day 4-8 Convective Outlook RESENT 1
NWS Storm Prediction Center Norman OK
0533 AM CDT Tue Jun 02 2026

Valid 051200Z - 101200Z

...DISCUSSION...
...Day 4/Friday...

The 00z ensemble mean solutions are in reasonable agreement in the
eastward progression of a low-amplitude short-wave trough through
the northern and central Plains into the upper Midwest, in tandem
with a surface front. Those features are expected to support
diurnally enhanced thunderstorm development, especially from parts
of the mid MO Valley into upper Midwest amidst a moist and
moderately unstable air mass. However, there is model spread in the
strength of vertical shear across the warm sector, which casts
uncertainty on organized severe-weather potential.


...Days 5/Saturday and 6/Sunday...

A vigorous short-wave trough moving onto the Pacific Northwest and
BC coasts Saturday morning is forecast to weak while lifting
northeast into the lee of the Canadian Rockies. A belt of enhanced
mid-level winds attending that system is forecast to overspread the
northern Rockies Saturday, and then the adjacent northern High
Plains on Sunday. The 00z EPS/GEFS/CMCE ensembles indicate
clustering in lee cyclone development across WY or MT on Saturday,
with considerably more spread in surface low positions by Sunday.
However, those data do suggest that a front will move into the
northern High Plains during the day Sunday.

Isolated severe storms appear possible across portions of central
and eastern MT Saturday, and perhaps portions of MT into ND on
Sunday. Low predictability will be maintained in these areas as it
appears that the better forcing for ascent may tend to spread north
into Canada. However, these areas will be monitored for a potential
upgrade to a 15% unconditional severe-weather probability in
subsequent outlooks. 

Elsewhere, there is reasonable model agreement in a mid-level trough
moving through the Great Lakes and Northeast, with a lower-latitude
system lifting north through the southern and central Plains. The
presence of a moist and unstable air mass will support strong to
isolated severe-storm potential from parts of the southern and
central Plains into Great Lakes on Saturday, and southern and
central Plains into Ozark Plateau and Mid-Atlantic States on Sunday.


...Days 7/Monday and 8/Tuesday...

The various ensemble mean solutions indicate some longitudinal
variance in an evolving mid-level trough in the vicinity of the
Pacific Coast. Elsewhere, the southern/central Plains trough
discussed in the previous section is forecast to weaken while
progressing into the upper Midwest. In general, these solutions
indicate the strongest mid-level flow confined to the Interior West,
and across Canada. The models suggest the most probable overlap of
that higher-momentum flow (and associated vertical shear) with a
moist and unstable air mass is from the northern Rockies into
northern High Plains during this time frame, supporting some
severe-storm threat.