240
ACUS02 KWNS 040523
SWODY2
SPC AC 040521

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1221 AM CDT Thu Jun 04 2026

Valid 051200Z - 061200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL AND
EASTERN NEBRASKA...NORTHERN KANSAS... MUCH OF IA...INTO SOUTHERN
MINNESOTA AND SOUTHWEST WISCONSIN...

...SUMMARY...
Scattered severe storms capable of large to very large hail,
damaging winds with potentially significant gusts, and perhaps a
couple of tornadoes are expected Friday afternoon into night across
portions of the central Plains into upper Great Lakes.

...Synopsis...

A series of weak, mid-level disturbances will translate from the
northern Plains into the upper Great Lakes, ahead of a building
ridge from central Canada into the northern Plains. At the surface,
the primary focus for strong to severe thunderstorm development is a
front, which is expected to stretch from the western UP of MI
southwest through the mid MO Valley into the central High Plains by
mid-afternoon Friday. A surface low is forecast to develop along the
front over south-central NE or north-central KS, with a dryline
extending south-southwest from that feature into northwest OK.


...Central Plains into the Upper Great Lakes...

Latest guidance is suggestive that the combination of steep
mid-level lapse rates and boundary-layer dewpoints in the upper 60s
to low 70s will support strong instability along and south of the
NE/IA segment of the front with HREF mean SBCAPE as high as
3000-4000+ J/kg. Forecast instability decreases with northeastward
extent into the upper Midwest, due in part to the potential for
early-day storms and lingering cloud cover.

While mid-level heights are forecast to rise through the day across
the central Plains, strong heating west of the dryline and south of
the surface front should sufficiently erode the cap for isolated to
widely scattered thunderstorm development by late afternoon into
early evening in the vicinity of the triple point over south-central
NE. Locally backed near-surface winds in that area will offset
somewhat marginal mid-level flow to yield 30-35 kt of deep-layer
shear, which will support supercell storm modes, given the degree of
instability. Large to very large hail and perhaps a couple tornadoes
will be possible in the early life cycle of the storms, with a
subsequent transition to more of a damaging wind threat (with
significant gusts possible) by mid/late evening.

Additional severe storms are expected farther east along the front
into IA during the afternoon and evening hours with strong
instability and modest vertical shear supporting a threat for large
to very large hail and severe wind gusts.

Should subsequent model guidance show higher confidence in more
concentrated storm development along the NE/IA segment of the front,
an upgrade to a level 3/Enhanced Risk may be considered.

Farther northeast along the front across the upper Midwest, the
diffuse nature of the boundary casts some uncertainty on exactly
where the favored area for diurnally enhanced storm development will
be. Nonetheless, the presence of a moderately unstable air mass and
modest deep-layer shear will be supportive of a few severe storms
capable of large hail and damaging wind gusts. An isolated
severe-weather threat may continue to spread east into the upper
Great Lakes Friday evening into night, driven largely by warm
advection along a westerly low-level jet.

..Mead.. 06/04/2026

$$