541
ACUS48 KWNS 021035
SWOD48
SPC AC 021033

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.

..Mead.. 06/02/2026