870
FXUS63 KARX 121805
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
105 PM CDT Sat Jul 12 2025

.KEY MESSAGES...

- For the rest of the weekend, look for smokey skies and
  seasonal temperatures.

- Next chance of widespread showers and storms comes Tuesday
  night into Wednesday. It remains too early to ascertain any
  severe weather potential.

- Cooler for the end of next week with highs in the 70s from
  Thursday into the weekend.

&&

.DISCUSSION...
Issued at 105 PM CDT Sat Jul 12 2025

This Weekend into Early Next Week: Smokey Skies, Mostly Dry

Smoke from upstream wildfires lingers for today and Sunday,
resulting in hazy skies and occasional reductions in visibility
(mainly tonight into Sunday morning). Moderating northwesterly
flow on the backside of our end of week front--coupled with the
smoke--keeps temperatures near or slightly below seasonal
values for the weekend (upper 70s to mid 80s). Looking into
early next week, a weak boundary shifts into the region for
Monday. How far south it advances will dictate where convection
is possible in the afternoon. Have added some slight chance PoPs
along where the boundary likely will be, but these will need
refining over the next 24-36 hours.

Tue - Wed: Next Chance of Widespread Showers and Storms

The main system of interest in this forecast approaches for
midweek, though confidence is not overly high in the impacts to
the local area. The upper level flow pivots from WNW to WSW
between Sunday night and Tuesday afternoon, allowing for
southerly surface flow to become reestablished over the region.
A shallow negatively-tilted wave ripples in from the High
Plains Monday evening and triggers a line of convection over
the Dakotas and northwestern MN that slowly propagates
southeastward into the evening. How far southeast the cold pool
from these storms advances sets the stage for where any severe
storms could develop Tuesday afternoon, At the moment, current
guidance favors storms initiating over central MN into
northwestern WI. Line parallel flow will limit the southeastward
progression of these storms, reducing confidence in how
widespread storms will be across our area before they begin to
wane overnight. The boundary sweeps through during the day on
Wednesday keeping the threat of showers in the forecast.

Late Week: Cooler, Uncertain Rain Potential

Confidence in the precipitation forecast wanes beyond midweek
as discrepancies increase in the placement of perturbations that
punctuate the progressive pattern. No matter how you slice the
forecast, the end of the week will see temperatures fall into
the 70s for highs, either through stronger cold air advection
with drier conditions, or under cloudy skies with periods of
showers. There is no strong signal in the longer range guidance
favoring a given scenario. Overnight lows will be driven by the
degree of cloud cover and could fall into the mid to upper 40s
(the NBM 10th percentile) in favored spots if conditions align
perfectly.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1224 PM CDT Sat Jul 12 2025

Primary concern in the TAFs is the presence of smoke due to
wildfires far to the northwest. At issuance, many locations
along and east of the Mississippi River have MVFR visibilities
but upstream obs suggest this initial round will give way to
VFR conditions this afternoon. Additionally, MVFR cumulus,
sometimes with enough coverage to constitute a ceiling, is
present along and east of the Mississippi River but expect this
deck to rise through the afternoon as frequently occurs.
Guidance and upstream obs point toward smoke returning
overnight so have included a return to MVFR at RST/LSE.
Otherwise, some fog is likely along the Wisconsin River tonight
but current indications are this is not favored along the
Mississippi River and LSE.

&&

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

&&

$$

DISCUSSION...Skow
AVIATION...Ferguson