701
FXUS63 KARX 281724
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1224 PM CDT Sat Jun 28 2025

.KEY MESSAGES...

- Scattered showers and storms this afternoon. Better chances
  (20-40%) will be in northeast Iowa and western Wisconsin.
  Severe weather chances look low, but cannot rule out a pulse
  severe storm.

- A line of storms will move east through Clark and Taylor
  counties during the early overnight. There might be some
  damaging winds if bowing segments can develop. Otherwise the
  remainder of the area will see a weakening line of storms move
  south into the area. There maybe some wind gusts of 30-50 mph
  in the wake of this line.

- Additional storms will possible along a quasi-stationary front
  near or south of Interstate 90 and ahead of an approaching
  shortwave trough on Sunday afternoon and evening. The main
  severe weather threat would be damaging winds.

&&

.DISCUSSION...
Issued at 1224 PM CDT Sat Jun 28 2025

Remainder of This Afternoon

A dying a mesoscale convective complex will move southeast
through the area this afternoon. The remnant MCV might produce
scattered showers and storms over northeast Iowa this
afternoon, and along and east of the Mississippi River after
28.20z. With weak shear, not anticipating any organized severe
weather. However, cannot rule out a pulse severe storm based on
instability of 2500 to 3500 J/kg (wet microbursts).

Tonight

Convection will develop ahead of a shortwave trough, currently
moving through western North Dakota and southeast Montana, near
the intersection of southeast North Dakota, northeast South
Dakota, and west-central Minnesota early this evening. As the
evening progresses, this will likely form into a linear
mesoscale convective complex which move east across central
Minnesota during the evening and then move east and southeast as
it moves into Wisconsin overnight. With this thunderstorm
complex moving away from the better forcing and into stronger
capping, there should be a gradual weakening of the line as it
moves south into our area. There may be some 30-50 mph wind
gusts north of Interstate 94 in the wake of these storms. If
there is any severe weather, it might be across Clark and Taylor
counties where the 850-700 mb winds and line orientation could
favor some bowing line segments.

Sunday and Sunday Evening

Expecting a quasi-stationary boundary to settle near or south of the
Interstate 90 corridor. Most unstable CAPES will build to around
3K J/kg by early afternoon. The combination of convergence
along this boundary, instability, and an approaching shortwave
trough from southwest Minnesota and northeast Iowa may result in
some redevelopment of showers and storms along this boundary and
along the shortwave. With weak 0-6 km shear and very warm air
mass aloft, thinking if severe weather happened to develop that
the primary threat would be damaging winds during the afternoon
and early evening.

Wednesday through Saturday

The models continue to show that 500 mb ridge will build across
the Northern Plains, Montana, and Wyoming. Meanwhile further
east there is a 500 mb trough over the eastern Great Lakes.
It continues to look like convection will develop during the
afternoons, but it now looks like it will be further west over
eastern Montana and the western Dakotas. This convection will
be initially supercellular during the afternoons. As their cold
pools coalesce, a progressive foward-moving mesoscale
convective complex will develop an move southeast toward either
the Mid- or Upper Mississippi River Valleys. With it now being
further west, we may see these systems move into the region more
in their decaying mode. As implied earlier, there is plenty of
uncertainty on whether they will track southeast through the Mid
and Upper Mississippi River Valleys.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1145 AM CDT Sat Jun 28 2025

Challenges persist through the weekend as a front sweeps in from the
northwest tonight, lingers across the area through Sunday. Multiple
smaller scale shortwave/mvc`s look to spin across the region, with
timing/location uncertainties. Atmosphere remains unstable, so only
needs a little kicker to spark shra/ts. Short term guidance having a
difficult time capturing these smaller scale features - limiting
usefulness at this time. Expect revisions to the forecast through
the weekend, leaning heavily into satellite/radar/sfc trends.

CIGS: SCT-BKN high level VFR clouds through the weekend. Some lower
with any convective features.

WX/vsby: as mentioned above, the atmosphere will be ripe for shra/ts
development, just need a forcing mechanism to spark it. With a lot
of uncertainties on where those could/would be...leaning into
keeping the TAFs dry for the moment.

WINDS: generally southerly through Sun morning with the usual
nocturnal decrease in speeds.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.

&&

$$

DISCUSSION...Boyne
AVIATION...Rieck