770
FXUS63 KARX 201945
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
245 PM CDT Sun Sep 20 2026

.KEY MESSAGES...

- Shower chances (30-60%) return on Monday for areas primarily
  along and south of I-90.

- Cooler than normal conditions are expected throughout much of
  the week with highs in the 60s.

&&

.DISCUSSION...
Issued at 245 PM CDT Sun Sep 20 2026

Monday: Shower Chances Return

As we head into the day on Monday, an upper-level trough/cut-off low
will eject into the region increasing potential for shower chances
during this period. Overall, highest confidence for seeing any
precipitation potential generally remains south of I-90 given the
position of this upper-level low and where the CAMs largely paint
precipitation during the afternoon and evening on Monday.
Consequently, much of the higher probabilities (50-80%) in the
HREF for measurable precipitation remain largely south of I-90
during this timeframe. Additionally, with the overall weaker
Q-vector convergence during this timeframe being the primary
forcing regime, probabilities in the HREF for rainfall totals
over 1 inch are very low (under 10%).

Tuesday - Friday: Staying Cool and Drier

By the time we get past Monday, northeasterly surface flow and high
pressure south of the Hudson Bay will allow for cooler and
drier conditions to advect into our region. As a result, median
high temperatures in the NBM throughout the week generally
remain in the 60s for most of the local area. As we head into
Wednesday morning, upper-level ridging will push into the local
area which in turn should both allow for a gradual warming trend
and clearing skies during this period. Consequently, not seeing
much for precipitation chances till later into the week when
maybe some shortwave perturbations try to sneak back into the
region during the Thursday and Friday timeframe. However,
predictability with these waves remains very low at this time.
In any case, will have to watch Wednesday morning for some frost
potential across north-central WI with median low temperatures
in the middle to upper 30s.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1250 PM CDT Sun Sep 20 2026

VFR conditions are expected throughout much of the TAF period with
low-level clouds scattering out over the afternoon. Winds will
generally remain from the northeast through the TAF period at around
8-15 kts. MVFR cigs may be possible (30-50% chance in  the HREF)
after 15z across portions of southeast MN and northeast IA as some
light rain moves through the region associated with an upper-level
system, however confidence in precipitation potential is low at this
time.

&&

.HYDROLOGY...
Issued at 245 PM CDT Sun Sep 20 2026

Some area river sites continue to see rises such as along the Root,
Cedar and Turkey Rivers. Volga at Littleport is the only site
that remains in moderate flood stage with multiple sites
remaining in minor flood stage. Rises at some sites will persist
into Monday before stage levels continue to recede throughout
the week. The only shot for precipitation in the next few days
is on Monday where rainfall totals generally around 0.25" or
less are expected which should not contribute to additional
rises. Otherwise, mostly dry conditions are expected through the
middle of this week.

&&

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

&&

$$

DISCUSSION...Naylor
AVIATION...Naylor
HYDROLOGY...Naylor