384
FXUS63 KARX 171033
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
533 AM CDT Thu Jul 17 2025

.KEY MESSAGES...

- Cooler temperatures and mostly dry conditions today and
  Friday with temperatures in the low 70s today and mid to upper
  70s for Friday.

- An unsettled pattern is setting up from the weekend to the
  middle of next week with several chances for rain. Next
  widespread rain chance (40 to 70%) is Friday evening through
  Saturday morning.

- Temperatures will gradually warm back up into mid to upper
  80s by Wednesday

&&

.DISCUSSION...
Issued at 333 AM CDT Thu Jul 17 2025

Today-Friday: Cooler, Mostly Dry

Surface high pressure shifts eastward over the Upper Midwest and
into the Great Lakes region today and tomorrow. Light northeast low
level flow will help to keep temperatures in the low 70s for most
today. Some locations may struggle to get out of the upper 60s. Low
temperatures for Thursday night will mostly be in the low to
mid 50s, with some potential (NBM 10th percentile) for areas
north of I-94 to get down into the 40s depending on cloud cover.
By Friday, the surface high shifts further east and warm air
advection begins to return. Temperatures warm up a little bit to
get back into the mid to upper 70s to near 80F. Mostly dry
conditions will linger through Friday afternoon.

Friday Night-Middle of Next Week: Unsettled Pattern, Warm Up

Primarily zonal flow aloft will continue through the middle of next
week as we sit on the northern fringes of a ridge that is centered
over the southern CONUS. Several shortwaves will move along the
northern edge of the ridge. While low PoPs (20 to 40%) are possible
most days, the best chance for rain will be near the baroclinic
zone. The first shortwave moves through Friday evening into Saturday
morning and the next one is late Saturday night into Sunday. At the
surface these waves will take the form of MCSs that develop in the
northern Plains and slide southeastward along the baroclinic zone
that currently looks to set itself up between eastern South Dakota
and northern Illinois. Focusing on the first wave, given that PWATs
are between 1.5 and 2.0 inches and the moisture transport looks
good, WPC has placed northern Iowa, southern Minnesota, and
southwestern Wisconsin in a slight risk for flooding. This risk for
flooding will continue anywhere along the baroclinic zone when these
MCSs move through as the aforementioned conditions continue through
the middle of next week. As we get closer to these MCSs occurring,
the hi-res timeframe will help in determining some of the
uncertainties (timing, trajectory, and location of heaviest
rainfall). High temperatures will stay in the upper 70s to low 80s
through Tuesday then warm back up into the mid to upper 80s for the
middle of the week.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 533 AM CDT Thu Jul 17 2025

With daytime heating and high pressure building into the area...low
level stratus will erode and conditions will improve into VFR
this morning. Have conditions improving to VFR by 13z at both
RST/LSE taf sites. Wind speeds will be 10 knots or less through
much of the taf period. With light winds and mostly clear skies
across the area tonight...there are hints patchy fog may form
after 06z in low lying and river valleys. At this time the fog
does not look to impact the LSE taf site.

&&

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

&&

$$

DISCUSSION...Cecava
AVIATION...DTJ