903
FXUS63 KARX 110539
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1239 AM CDT Fri Sep 11 2026

.KEY MESSAGES...

- Shower and storm chances return tonight into Saturday morning
  (30 to 60%). Severe potential is low (<10%) with these
  storms.

- Widespread rain is likely Monday into Tuesday (70 to 90%) with
  the potential for localized flooding.

&&

.DISCUSSION...
Issued at 1239 AM CDT Fri Sep 11 2026

Today Through Sunday: Trending Cooler with Some Storm Chances

An upper level low pressure system sitting over the northern
Canadian Prairie provinces should slowly move east today. As
this occurs, a weak surface front is forecast to move southeast
from the Dakotas towards the Upper Mississippi River valley.
This feature may be timed well with a weak shortwave on the
southern periphery of the low to generate showers and storms
ahead of the front. Severe thunderstorms are possible across
much of Minnesota, but the severe storm threat is much lesser
across our CWA. The timing of the frontal passage is not ideal
for strong instability as it moves over the region early
Saturday morning. A line of showers/storms may form during this
time frame, but the severe storm potential will be quite low.

Mostly zonal flow is expected through this upcoming weekend and this
pattern should usher in a cooler airmass over the area. Temperatures
from today through Sunday should steadily decrease, with highs
tomorrow in the lower 80s to upper 70s and highs on Sunday in
the mid 60s to lower 70s. For those that are looking forward to
Fall, the weather will sure begin to feel like it this weekend!
In addition to the cooler temperatures, rain chances may start
to ramp back up Sunday afternoon into the night. There are
timing and location differences in the forecast model suite that
does lead to some uncertainty as to where the rain will set up
on Sunday. In any case, the rain showers or storms are not
expected to cause flooding at this time through Sunday night.

Monday and Tuesday: Widespread Rain with the Potential for Flooding

A stronger H500 trough will move over the Northern Rockies towards
the Northern Plains on Monday. With high pressure remaining over the
southeastern CONUS, this will open the door for southwesterly flow
to bring very rich Gulf of America moisture to the Upper Midwest.
Blended ensemble forecast guidance continues to depict mean PWAT
values approaching 2 inches throughout the day on Monday. A few
rounds of rain are possible throughout the day, with the first
likely already ongoing at daybreak. The second round arrives a bit
later on Monday, mainly in the evening towards night time hours, as
a cold front moves east towards the region. The combination of both
rounds of rain will likely result in a good portion of the area
receiving 1-2 inches of rainfall. Given the high moisture throughout
the atmosphere, the potential will exist for flooding and some of
the ensembles are hinting at this potential with the most extreme
solutions showing rainfall amounts of 3-5 inches by Tuesday morning.
How quickly the rain ends will be dependent on how quickly the drier
airmass moves in behind the frontal passage, so it is not out of the
realm of possibility that some locations may continue to get rain on
Tuesday.

Rest of Next Week: Rain Chances Continue with Cooler Temperatures

High temperatures through at least the middle of next week are
expected to remain in the 60s to 70s each day aided by the rain
chances and increased cloud cover. Another potential for rain may
arise on Wednesday night into Thursday as mid level moisture
increases once again and potential shortwaves round the top of the
upper level high over the southeastern US. With that being said, it
will certainly begin to feel like Fall with the increased chances
for rain along with cooler daytime highs and overnight lows
throughout all of next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1239 AM CDT Fri Sep 11 2026

VFR conditions for most locations through the TAF period. Fog
should stay confined to river valleys in far southwest
Wisconsin. Winds gradually increase this morning with areas in
southeast Minnesota and portions of both northeast Iowa and
west-central Wisconsin seeing sustained southwest winds of 15 to
20 kts with gusts of 25 to 35 kts. These winds gradually
decrease further into the evening.

&&

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

&&

$$

DISCUSSION...Muscha
AVIATION...Cecava