172
FXUS63 KARX 020453
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1150 PM CDT Fri Aug 1 2025

.KEY MESSAGES...

- Wildfire smoke is likely to persist into the weekend bringing
  hazy skies, reduced visibilities, and decreased air quality.

- Rain chances return towards the middle of next week and linger
  into the weekend.

- Mild temperatures through early next week before warming up
  into the mid to upper 80s for the rest of the week.

&&

.DISCUSSION...
Issued at 131 PM CDT Fri Aug 1 2025

Today-Monday: Lingering Smoke, Mostly Dry Conditions

Surface high pressure remains over the Great Lakes and Upper Midwest
through the weekend. Currently, the surface high is situated over
the Upper Midwest and will remain here through tomorrow before
shifting eastward on Sunday. As a result, surface winds will be
light and out of the northeast today then shift to southerly winds
for Saturday and Sunday. The winds aloft remain from the northwest
until Sunday when a couple of shortwaves move through and bring rain
to the northern Plains. With the current flow pattern we are in,
smoke will continue to stick around through at least Saturday. There
is some uncertainty as to when the smoke leaves the area as smoke as
gone as far south as mid and lower Mississippi River Valley regions
and when the flow pattern shifts from the south, that smoke will
come back. The question is how dense the smoke concentration at the
surface will be compared to what it is now. The amount of smoke
aloft is expected to remain on the higher side with the continued
northwest flow aloft. Similarly, the uncertainty is how much of this
makes it down to surface.

Precipitation wise, with the surface high overhead, will be quite
minimal through Monday. There are a couple of shortwaves that move
through on Sunday that increase rain chances in the northern Plains,
however these chances do not make it into our CWA. Earlier forecasts
had low PoPs potentially coming in on Sunday, however those
increased chances have moved westward. Despite shortwaves moving
through on Sunday and Monday, the lower levels remain relatively dry
so even if rain can make into our CWA it would likely fall as virga.
Temperatures over the next few days will remain in the mid 70s to
near 80F and gradually warm up into the low 80s for some locations
by Monday.

Tuesday-Friday: Warm Up, Precipitation Chances?

More shortwaves are expected to move through the Upper Midwest
through the end of next week. The main difference from the early
week disturbances, warm southerly flow returns increasing dewpoints
back into mid 60s to low 70s by the latter half of next week. Low
end PoP chances (20 to 40%) remain in the forecast as a result from
those disturbances. Even though the majority of EPS and GEFS have
measurable rain later next week, there are still differences in
exact timing of when the rain moves through. As previously
mentioned, warm southerly flow returns next week. Temperatures will
gradually warm up into the mid and upper 80s by Wednesday and linger
into the weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1150 PM CDT Fri Aug 1 2025

CIGS: sct-bkn 4-5kft clouds making their way east in the early
overnight. Otherwise, expect mostly SKC/SCT conditions through Sat
night, likely persisting into Sunday.

WX/vsby: wildfire smoke will continue to impact the region this
weekend with vsbys generally from 4 to 7 miles.

Setup very good with widespread river valley fog early this morning -
with the aforementioned clouds being the one drawback. If more
clearing is realized at KLSE, the likelihood for a 1-3 hour period
of 1/4-1/2SM increases. For now, will hold with a TEMPO for 1/2SM
and monitor satellite/sfc ob trends. Winds within a few hundred of
the sfc stir at 10+ kts via the NAM later Sat night, working against
fog impacts at KLSE for Sun morning.

WINDS: light (under 10kts) from the southeast/south through the
period.

&&

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

&&

$$

DISCUSSION...Cecava
AVIATION.....Rieck