571
FXUS63 KARX 010626
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
126 AM CDT Thu Oct 1 2026

.KEY MESSAGES...

- Ongoing heavy rain locally affects parts of northeast Iowa
  into far southwest Wisconsin with 2 to 2.5 inches of
  precipitation expected through today.

- Cooling trend into new week increases frost/freeze concerns
  mainly Monday morning.

&&

.DISCUSSION...
Issued at 120 AM CDT Thu Oct 1 2026

Today: Widespread Rainfall

A widespread area of moderate rainfall is slowly making its way
north and east out of the Central Plains and into the Mid/Upper
Mississippi River Valley. Heavier rainfall is just making it into
Northeast Iowa and Southwest Wisconsin late overnight with the
heaviest of the precipitation still back near the core of the low
around Omaha, NE. That will trek NE through the remainder of the
overnight hours and through the morning. This will be co-located
with precipitable water values in the 1.6-1.9 inch range. The latest
01.00 HREF 6 hour precipitation LPMM shows a few blotches of 3.5-4
inches across far southern portions of Fayette, Clayton, and Grant
Counties. While there is still a 15-30% chance for 3-4 inches in
those aforementioned locations, more likely totals will be
closer to 2-2.5 inches.

There will be a fairly sharp northern cutoff in QPF with
locations outside of Northeast Iowa and Southwest Wisconsin
likely not seeing more than 0.5 inches of rain by 12Z Friday,
evident in a sharp cutoff of precipitable water values in 01.03
RAP analysis. PWATs drop off to less than 1.5 inches as one
moves north of the IA/MN state line with moisture transport
more prominent south of our area across Southern and Central
Iowa. This moisture transport will continue into northeastern
Illinois and southern Wisconsin where the axis of heavy rain
will extend by morning. The heaviest rain should push off to the
east by mid morning as a cold front starts to move in from the
northwest. Rain chances will gradually end through the day with
most locations dry by 00Z Friday.

Thursday Night - Friday Night: Dry and Slightly Cooler

High pressure is expected to build in behind the aforementioned cold
front. High temperatures Friday will be slightly cooler in the upper
50s to low 60s with lows Thursday night in the upper 30s to upper
40s. Friday night lows will drop into the mid 30s to mid 40s and
some places across central and north central Wisconsin could see
their first areas of frost this fall.

Saturday - Mid Next Week: Low Rain Chances Sat PM, Dry to Follow

Another cold front is expected to move southeast through the region
Saturday afternoon/evening. Low potential for weak scattered
showers across portions of Southeast Minnesota and West Central
Wisconsin Saturday evening accompanying frontal passage but
overall QPF amounts remain low, from 0.01-0.02 inches. This
would be a quick hitter and likely wouldn`t even have much of an
impact on temperatures as highs Saturday and Sunday will be
comparable in the mid 60s. The only thing of note would be the
potential for frost across portions of Central and North-
Central Wisconsin Monday morning as low temperatures could fall
into the mid-30s across that region. Otherwise, high pressure
looks to keep conditions dry next week with high temperatures
generally in the 60s to near 70 degrees.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1247 AM CDT Thu Oct 1 2026

Precipitation shifting east-northeast into the local forecast
area mainly from northeast Iowa into southwest Wisconsin is
south of both local TAF sites (KLSE/KRST), affecting smaller
airports with MVFR-IFR visibilities and ceilings. LIFR-IFR FG/BR
to the northwest of this main precipitation shield is affecting
both TAF sites and smaller airports into central Wisconsin.
Expect light rain to near KRST and affect KLSE through the early
morning hours as FG/BR impacts persist. As the low center, well
south of the forecast area, pivots east, north surface winds
increase, potentially mixing and quickly bettering impacts near
12Z. Have accounted for this with hourly step increase at
KRST/KLSE TAFs near this time. Stronger north winds persist
through much of the daytime hours with VFR after overnight
impacts.

&&

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

&&

$$

DISCUSSION...Barendse
AVIATION...JAR