236
FXUS63 KARX 101850
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
150 PM CDT Thu Sep 10 2026

.KEY MESSAGES...

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

- Widespread rain is likely Monday (70 to 90%) with some
  potential (15%) for heavy rain and localized flooding
  concerns.

&&

.DISCUSSION...
Issued at 150 PM CDT Thu Sep 10 2026

Thunderstorm potential returns Friday night

Friday into Saturday, upper low churning over northern Saskatchewan
should usher a weak front south through the CWA. As this occurs,
disturbance within the quasi-zonal flow aloft over the Upper Midwest
will eject eastward, potentially (30-60%) leading to showers and a
rumble of thunder. While shear appears supportive of severe
thunderstorms, instability decidedly does not. Indeed, 10.00z LREF
joint probabilities of sufficient shear, instability, and lack of
CIN for severe storms are near zero. This is largely in line with
the overnight timing of the upper disturbance, right in the right
part of the day to expect issues with instability. Thus, while
including rain in the forecast is prudent, am not concerned about
hazards aside from stray lightning.

Rainy Monday with flooding potential

Sunday into Monday, strong upper wave moves over the Rocky Mountains
to the northern Dakotas as ridging continues to be present in the
southeastern CONUS. With lee pressure falls occurring across the High
Plains, this will induce robust southerly moisture advection from
the Gulf. By Sunday night, 10.00z LREF suggests PWAT values around
1.6" with potential (10%) for this to exceed 2". 10.00z guidance
suggests precip will fall in 2 phases: 1) as WAA ramps up early
Monday and a lead disturbance ejects northeastward over WI and 2) as
the cold front pushes southeast during the evening. Locations that
see moderate rain during both phases have a small chance (10-15%) to
exceed 4" in rainfall with extreme outcomes across the 10.00z
GEFS/ECENS/CMCE having over 7". Will need to monitor this closely,
particularly if guidance trends toward a less progressive pattern
with a lingering warm front, as those extreme outcomes would come
into play more.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1242 PM CDT Thu Sep 10 2026

VFR conditions expected over the next 24 hours with the
exception of river valley fog within the Wisconsin and Kickapoo
valleys near OVS overnight. Some cumulus at or around 5 kft has
formed early this afternoon and should persist for the next
several hours. Winds become south-southwesterly by the end of
the period with gusts to 25-30 knots possible west of the
Mississippi valley, including RST, late in the period.

&&

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

&&

$$

DISCUSSION...Ferguson
AVIATION...Ferguson