274
FXUS63 KARX 031243
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
643 AM CST Tue Mar 3 2026

.KEY MESSAGES...

- Thursday brings rain potential (15-50%) to the region but this
  will likely remain southeast of the Driftless Area.

- At least 1" of rain still plausible (30-80%) Friday into
  Saturday. A possibility (20-30%) for thunderstorms Friday
  evening as well.

&&

.DISCUSSION...
Issued at 1124 PM CST Mon Mar 2 2026

Rain likely remains southeast Thursday

Wednesday into Thursday, upper low currently over the Great Basin
barrels eastward over northern IL/IN. 850mb moist advection ahead of
this feature should bring enough northward from the Gulf for a
shield of precip to develop with progged thermal profiles suggesting
an all-rain event. For our neck of the woods, 02.12z to 03.00z
operational GFS/EC/NAM keep most of the rain to our south/east.
Given this, was tempted to cut PoPs from NBM values before 00z
Friday. However, 02.12z LREF and the 02.12z CMC suggest enough
support remains to hold onto a mention (15-50%) of rain across most
of the area with best chances in far SW WI. In any case, amounts do
not draw concern, as 03.01 NBM has only a 10% chance to reach 1" of
accumulation and this is largely limited to Grant County WI.

Rain likely Friday into Saturday with potential for thunderstorms
and heavy rain.

Longwave upper trough moves over the western CONUS Thursday with a
lead wave ejecting northeast toward Lake Superior Friday into
Saturday before the main upper trough slides eastward Saturday
night. Extended period of southerly moist advection will likely lead
to an anomalously moist air mass being in place - 02.12z NAEFS PWATS
are above the 99.5th percentile of model climatology. Thus, while
the overall pattern is progressive, 03.01z NBM is bullish for this
far out (30-80%) that a good chunk of the area will see more than 1"
of rain across Friday and Saturday. While highs in the 40s and 50s
are favored Tuesday through Saturday, some remaining frost in the
soil may lead to additional runoff and some rises on creeks and
streams. As for other hazards, 03.00z GFS MUCAPE rises to around 500
J/kg Friday evening so have kept thunder in the forecast. While not
a big possibility at this time, CSU GEFS ML guidance suggests an
outside shot at a severe storm, certainly plausible - focusing on a
hail risk - given strong flow aloft leading to robust deep shear and
seasonably cold temperatures aloft.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 535 AM CST Tue Mar 3 2026

VFR to MVFR conditions currently present across the area. Much of
the precipitation from earlier overnight has dissipated or
stayed south of the terminals so expect dry conditions for the
remainder of the period. MVFR CIGs will likely linger through
the morning before scattering out to VFR by the afternoon.
Lingering moisture across the area will allow for the
development of fog across much of the area tomorrow morning so
have included some mentions of BR based on current guidance.
This may need to be degraded to FG with later packages/increased
guidance. Ceilings will also degrade, especially at KRST, late
in the period with IFR to LIFR CIGs looking more and more
likely. Winds will remain light and variable.

&&

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

&&

$$

DISCUSSION...Ferguson
AVIATION...Barendse