Clearpost.online It's your post, so post it!

Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1140 PM CDT Sun Jun 26 2022

Valid 281200Z - 291200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TUESDAY
AFTERNOON AND EVENING ACROSS PARTS OF NORTHERN AND CENTRAL
MONTANA...AS WELL AS CENTRAL INTO SOUTHERN WISCONSIN AND ADJACENT
PORTIONS OF SOUTHEASTERN MINNESOTA AND NORTHEASTERN IOWA...

...SUMMARY...
Strong thunderstorms may impact parts of the northern Rockies
vicinity, as well as parts of the Upper Midwest, Tuesday afternoon
and evening, acco*panied by at least some risk for severe weather.

...Synopsis...
Models continue to indicate little change to the general large-scale
split flow across the northeastern Pacific and adjacent portions of
northwestern North America, but a lingering, initially co*pact low
emerging from persistent mid-level troughing offshore of the U.S.
Pacific coast is forecast to progress inland during this period.  As
it does, it appears likely to undergo considerable deformation
within an increasingly confluent regime, between larger-scale
downstream ridging slowly shifting east of the Rockies and a much
more prominent mid-level low beginning to dig southeast of the north
central Canadian Arctic latitudes.

Farther east, larger-scale mid-level troughing will persist, with
some eastward progression across the eastern Canadian provinces,
adjacent Great Lakes region and Northeast.  The most prominent
perturbation within this regime is forecast to turn
east-northeastward across the southern Hudson/James Bay vicinity. 
However, another fairly vigorous trailing impulse probably will dig
across the Upper Midwest/Great Lakes region, just in advance of the
building upstream short wave ridging.

In association with these developments, another surface cold front
is expected to advance south of the central Canadian/U.S. border, in
the wake of a more prominent preceding front which will continue to
weaken across the Gulf Coast vicinity.  However, seasonably high
boundary-layer moisture content likely will remain confined to the
Gulf Coast.

...Upper Midwest...
Pre-frontal boundary-layer moistening may largely be limited to that
associated with evapotranspiration through this period.  However, it
is possible that surface dew points may increase into the mid/upper
50s near the nose of a narrow pre-frontal corridor of stronger
daytime heating emanating from the northern Great Plains.  Beneath
relatively cool mid-level air, steepening low-level lapse rates may
beco*e supportive of mixed-layer CAPE up to 1000 J/kg across parts
of southeastern Minnesota into central Wisconsin.  

While the front may beco*e one focus for thunderstorm development as
it advances southward through upper Michigan and northern Wisconsin
Tuesday afternoon, as the southwestern flank of this activity
encounters this environment there appears potential for substantive
intensification.  Additionally, isolated discrete storms may form
ahead of the cold front, in response to low-level warm advection,
and perhaps forcing associated with a digging mid-level jet streak
(around 50 kt at 500 mb).

Aided by strengthening deep-layer shear, it is possible that the
environment may beco*e conducive to a supercell or two and perhaps
the evolution of a small organized cluster posing a risk for severe
hail and wind while spreading southeastward across central into
southern Wisconsin through mid to late evening.

...Montana...
Moisture may only beco*e supportive of CAPE on the order of 500 J/kg
or so, but strong heating and deep boundary-layer mixing is forecast
within deepening surface troughing across parts of central into
northern Montana Tuesday afternoon.  As forcing for ascent
downstream of the inland progressing mid-level low shifts across and
east of the higher terrain, associated thunderstorm development may
be maintained east of the higher terrain, perhaps consolidating into
one or two growing clusters with increasing potential to produce
strong outflow and occasional severe surface gusts.  It appears that
this will be aided by downward mixing of 30-40 kt mid-level flow,
coupled with the cooling associated with melting and evaporation of
precipitation within the well-mixed sub-cloud air.

..Kerr.. 06/27/2022