212
FXUS63 KARX 120559
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1259 AM CDT Fri Jun 12 2026

.KEY MESSAGES...

- Less humid today and turning breezy this afternoon, especially
north of I-94 with gusts approaching 35 to 40 mph.

- Showers and some storms develop north of I-90 tonight with
greatest chances (60-80%) north of I-94. Rain chances then shift
southward during the day Saturday.

- Big pattern shift arrives Sunday with cooler than normal
conditions lingering through much of next week.


&&

.DISCUSSION...
Issued at 1258 AM CDT Fri Jun 12 2026

Less humid today and turning breezy this afternoon

A less volatile weather pattern is in store as the week draws to a
close. The biggest tangible change will be considerably lower
humidity, making it feel much more pleasant. Upper level flow will
turn more zonal today as troughing slips off to the east. Steep low
level lapse rates this afternoon will allow for very deep mixing to
around 750 to 700mb. This will promote breezy westerly winds,
potentially mixing down gusts approaching 35-40+ mph across our
northern counties per forecast soundings (50% chance). Thinking the
RAP/HRRR are over-mixed with 45-55 kts at the top of their mixed
layers all the way up to 650-600 mb.

Showers and some storms return tonight north of I-90

Heading into this evening, MSLP reveals a col developing over the
Upper Mississippi Valley at the intersection of surface ridging and
troughing. A quasi-stationary front will lay out just northwest of
the forecast area. Associated frontogenetic forcing, combined with
weak moisture transport on the nose of a low level jet, will promote
developing showers and perhaps a few storms over southern Minnesota
into northern Wisconsin this evening. Instability will be
diminishing, but there looks to be at least a few hundred J/kg
MUCAPE that could support some rumbles of thunder. Clark and
especially Taylor counties will be most prone to the rainfall, where
the 12.00Z HREF has 40-90% probabilities for a quarter inch or more
and 30-60% probabilities for a half inch or more by Saturday morning.

Shower and storm chances shift further south on Saturday

During the day Saturday, upper level troughing overhead will
gradually deepen, nudging the front southward. Daytime instability
building south of the front will favor additional shower and storm
chances, especially by afternoon. The forecast currently calls for
40-60% PoPs from northeast Iowa into central Wisconsin, but those
values are likely to increase as we get closer in time. The NBM has
highest rainfall amounts across far northeast Iowa and far southwest
Wisconsin where the 90th percentile is between 0.75 to 1".

Big pattern shift next week to considerably cooler than normal

A pretty dramatic pattern shift is in store for Sunday as deep upper
troughing takes hold over the CONUS. High temperatures will likely
struggle to break 70 in some areas despite abundant sunshine. The
long range ensembles (GEFS/ENS/GEPS) mean max temperature Sunday
afternoon is generally in the mid 60s with the 90th percentiles
generally in the upper 60s to around 70. This continental polar
airmass will linger but slowly moderate through the middle of next
week with highs gradually warming through the 70s. Gulf moisture
begins to return Tuesday into Wednesday in short conjunction with
some shortwave energy. This will bring the next chance of showers
and some storms toward the middle of the week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1210 AM CDT Fri Jun 12 2026

VFR conditions and mostly clear skies expected for the next 24
hours. Westerly winds will prevail for much of the period with winds
picking up later this morning with gusts to between 20-30 kts at the
terminals continuing through the afternoon hours. Gusts will
come down by around 00Z with winds backing to a more
south/southwesterly direction late in the period.

&&

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

&&

$$

DISCUSSION...Kurz
AVIATION...Barendse