231
FXUS63 KARX 031104
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
604 AM CDT Sat Oct 3 2026

.KEY MESSAGES...

- Rain chances (20-60%) increase this afternoon and tonight
  near and north of I-90. Rainfall amounts under 0.25" are
  expected.

- Potential for frost Sunday Night/Morning morning in central
  and north-central Wisconsin.

- Near to slightly above normal temperatures into next week
  with highs in the 60s and 70s

&&

.DISCUSSION...
Issued at 259 AM CDT Sat Oct 3 2026

Today - Tonight: Increasing Rain Chances North of I-90

GOES-19 water vapor imagery depicts a fairly progressive
shortwave trough moving through Manitoba which will be the next
system to bring any precipitation potential into the region
(20-60%). As this wave swings into the Upper Midwest later this
afternoon and evening, much of the CAMs generally agree on
instigating an area of showers for areas near and north of I-90
along a diffuse warm front and along the associated synoptic
cold front with the aforementioned wave. However, given
precipitable water values slightly over 1" and MUCAPE values of
around 100 J/kg in the recent RAP, high confidence (80%+) for
precipitation amounts to remain limited. Evident in recent HREF
(03.00Z) rainfall probabilities for over 0.25" of only 10 to
40%. Due to the progressive nature of this shortwave, the
synoptic cold front swings through the area fairly quickly with
much of the precipitation potential exiting the local area
around midnight.

Sunday - Monday: Frost Potential Sunday Night/Monday Morning

As we head into Sunday and Monday, northwesterly flow in the wake of
the aforementioned system will keep temperatures somewhat cool for
Sunday and Monday with highs in the 60s areawide. Supplementary
shortwave upper-level ridging builds into the area as well with
accompanying surface high pressure. Consequently, expecting
skies to clear for much of the day on Sunday and Monday with
winds trending lighter. As a result, when considering decent NBM
probabilities (40-70%) for low temperatures below 37 degrees
during the morning hours on Monday and the aforementioned lack
of sky cover, confidence for frost across portions of central
and north-central Wisconsin is increasing during this timeframe
and Frost Advisories may be needed in subsequent forecast
updates. Otherwise, the fairly profound area of surface high
pressure over the region during this period should mitigate any
precipitation potential.

Tuesday - Friday: Staying Dry, Near to Slightly Above Normal
Temperatures

The synoptic pattern starting Tuesday will remain relatively
steady-state with some indications of increasing upper-level
ridging later into the week. Consequently, median high
temperatures in the NBM staying in the 60s to lower 70s. The
relatively persistent surface high pressure with a lack of any
shortwave perturbations in northwesterly synoptic flow limits
precipitation potential through Friday. This is evident in low
(<20%) grand ensemble (GEFS/EC/Canadian ensemble) probabilities
for measurable precipitation through Friday.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 602 AM CDT Sat Oct 3 2026

VFR expected through the 03.12Z TAF period at both TAF sites.
MVFR-IFR possible at smaller airports in locally northern
counties (KMDZ) overnight tonight. Have increased cloud
coverage across northern half of the forecast area compared to
previous forecast albeit remaining VFR.

Should further southern shift to precipitation potential,
accompanying higher sky coverage, and potential impacts then
could see precipitation and accompanying potential ceiling
impacts tonight at local TAF sites (KLSE/KRST). Current
confidence remains low and therefore have omitted from current
TAF at the longer forecast hour.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Frost Advisory until 7 AM CDT this morning for WIZ017.
MN...None.
IA...None.

&&

$$

DISCUSSION...Naylor
AVIATION...JAR