417
FXUS63 KARX 232316
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
616 PM CDT Sun Aug 23 2026

.KEY MESSAGES...

- Pleasant temperatures are on the docket for the upcoming week
  with highs in the mid 70s to mid 80s, warmest for Monday and
  Tuesday.

- The risk for thunderstorms returns for Tuesday afternoon and
  evening, some of which may be on the stronger side.

- Showers may linger in Wisconsin into Wednesday, with the next
  round of rain not expected until next weekend.

&&

.DISCUSSION...
Issued at 1230 PM CDT Sun Aug 23 2026

This Afternoon - Monday: Pleasant and Dry, Cool Tonight

Northwesterly upper tropospheric flow continues into Monday
with surface high pressure gradually sliding across the region
between this afternoon and Monday afternoon.

Tonight`s main forecast concerns revolves around temperatures
and fog along and east of the Mississippi River, both of which
hinge on the degree of cloud cover that spreads southeastward
from northern High Plains convection later this afternoon. The
high cirrus shield is not overly thick in the forecast
soundings, which could result in a complex scenario where lower
temperatures and fog shift in space and time depending on the
cloud cover. Should the clouds wane, lows tonight could touch
the upper 30s in the favored sand bogs and fog could be dense in
the valleys. The alternate scenario is lows stay more in the
mid-40s with little fog should the clouds come in thicker.

Tuesday Afternoon: Storm Potential

Little change to the going forecast for the risk for strong to
even severe storms Tuesday afternoon and evening as a notable
mid-tropospheric vort max/shortwave crests our upstream ridge
and digs into Minnesota. Forecast profiles continue to show a
favorable wind profile featuring elongated low to mid-level
hodographs normal to the surface front that would support
organized supercellular structures. The issue in the more recent
medium range soundings has been an EML and deep sub-cloud
mixing, which rapidly erode the available instability.

Will have to monitor conditions upstream carefully Monday
night into Tuesday morning to see if the previous day`s
convection can modulate this lower tropospheric airmass to
support more vigorous updrafts. Even a slight cooling and
moistening to these profiles could quickly change how these
storms evolve, so stay tuned for further updates.

End of the Week: Drier Once Again, Possibly some Weekend Rain

A few showers may linger in central Wisconsin on Wednesday within
cyclonic flow following our late Tuesday storms, but most of
the area should stay dry for the day. Upper level ridging and
surface high pressure return for the end of the work week
bringing similar conditions as we are seeing to start the week.
The pattern grows more active heading into the weekend with the
potential for more widespread rainfall in excess of 1 inch.
However the position of the synoptic features are not well-
resolved and make it difficult to delve into at this range.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 616 PM CDT Sun Aug 23 2026

Main aviation forecast concern revolves around potential fog
development in valleys and low-lying areas late tonight, mainly
east of the Mississippi River. The overall setup is favorable,
but expected incoming high clouds will be the complicating
factor. Recent runs of the NBM have trended toward a bit more
cloud cover and thus slightly lower probabilities for MVFR fog
at LSE. Will monitor satellite and guidance trends this evening
for 06Z TAF.

Otherwise VFR with light and variable to calm winds overnight,
becoming south to southwest by late Monday morning.

&&

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

&&

$$

DISCUSSION...Skow
AVIATION...Kurz