812
FXUS63 KARX 270545
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1245 AM CDT Mon Jul 27 2026

.KEY MESSAGES...

- Severe storm chances continue through this morning with the
  primary hazards being damaging wind gusts and large hail.

- Dangerously hot conditions are expected once again this
  afternoon with heat index values approaching 110. These hot
  temperatures can cause heat related illnesses.

&&

.DISCUSSION...
Issued at 1242 AM CDT Mon Jul 27 2026

Through This Morning: Uncertain Severe Storm Chances

Multiple clusters of showers and storms continue to develop
from southeastern Manitoba to north central Wisconsin at the
time of this writing. Even though the environment is conducive
for severe storms to form with plenty of instability and shear,
the upper level ridge is keeping the convection mostly
suppressed so far throughout this event. Mid level capping
continues to win out even though a few storms so far this
evening in northeastern Minnesota have shown signs of tapping
into the better environment, but they have not lasted long.
Upper level lift, which is currently located over northeastern
ND into Manitoba, should continue to round the ridge and develop
storms over northern Minnesota. Those storms should move
southeast into Wisconsin going into this morning.

There continues to be tremendous uncertainty regarding timing,
location, and severity of storms tonight into Monday morning.
The hi-res forecast models continue to have no run-to-run
consistency and all offer differing solutions. Based on recent
observational trends and satellite interpretation, the current
expectation is leaning towards a later start to any potential
severe storms, potentially not impacting the forecast area until
sunrise or later on this morning. If that scenario ends up
panning out, the potential is there for a damaging wind gust
event across portions of Wisconsin and further east, especially
if any sort of daytime heating can occur before storms reach the
region leading to lesser CIN. Large hail would also be possible
but a lesser concern as the storms are expected to form along a
line. Another potential scenario is that the storms or line of
storms completely misses the FA to the northeast and east if the
axis of the ridge is too far northeast across the area, which
would direct storms around the CWA. There are even further
solutions that suggest the storms that are currently ongoing
will be able to form into severe storms in the next few hours.
That scenario currently has the lowest confidence in panning out
based on observational trends with the other two scenarios
having equal confidence in occurring, even though that
confidence remains very low right now.

Additional development may occur as the shortwave along with a
surface boundary move across the region this morning. Model
guidance shows the front moving across during the morning hours
and where ever the front interacts with a potential line of
storms or any outflow boundaries, that could be enough to
quickly generate storms. Where or if any interaction occurs
remains very low in confidence. To summarize this all,
confidence in any severe storms and their timing or location, is
very low but the environment will remain highly conducive for
severe storm development through this morning.

Rest of Today: Dangerous Heat and Additional Storm Chances

Confidence in the dangerous heat has also decreased due to the
later push of potential storms along with cloud cover. Plentiful
surface moisture is expected to remain in place to lead to high
heat index values if sufficient daytime heating can occur,
which could lead to heat index values of 100 or higher. The
potential for morning fog combined with cloud cover and
potential convection has led to uncertainty in the highest
afternoon temperatures at this time. The previous heat headlines
remain in place given the high potential still for heat index
values to reach or exceed 100 across most of the area. With how
much moisture is in place, a few isolated afternoon storms may
try to form but confidence in that remains quite low.

Tuesday into Next Weekend: Warm Temperatures and Storm Chances

The ridge shifts westward just enough and northwest flow
remains in place mid week. Both of these will mean temperatures
cool down marginally, into the mid to upper 80s along with lower
heat index values. The potential for heat index values to reach
or exceed the triple digit mark is low Tuesday and beyond. With
this flow pattern, ensemble guidance has low precipitation
chances through midweek with better chances as we head towards
the weekend. The ridge is expected to become suppressed far
enough south for stronger troughs to push across the Northern
Plains into the Midwest which should trigger a few rounds of
rain potential at the end of this week into the weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1242 AM CDT Mon Jul 27 2026

Somewhat of a challenging forecast tonight as models struggle
to handle ongoing showers and storms over northern
Wisconsin/northeast Minnesota. Thinking that said showers and
storms will largely remain north and east of the region through
much of the overnight before coverage increases after 10-12z.
Because these showers/storms have stayed to the northeast,
patchy fog is expected to and has begun to develop, resulting
in visibility restrictions to some sites including KRST. Lots
of uncertainty remains in how showers/storms will evolve after
that 10-12z timeframe, leading to a low confidence forecast
through at least mid-day. Areas east of the Mississippi River
are most likely to see showers and storms though, highlighted by
the 27.00z REFS/HREF which suggest a 20-40% chance of
precipitation.

Confidence in the forecast increases this afternoon into
tonight. A surface front is expected to move through the
region, shifting tonight`s southerly winds to the northwest
along with some gusts to around 20KT. Near surface smoke also
looks to be on the rise along the front, though not to the
extent of last week. Have included some mention of slightly
reduced visibilities to account for the smoke, but visibilities
improve with time tonight as smoke clears out behind the front.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Extreme Heat Warning until 9 PM CDT this evening for WIZ041-
     042-053>055-061.
     Heat Advisory until 9 PM CDT this evening for WIZ032>034-043-
     044.
MN...Extreme Heat Warning until 9 PM CDT this evening for MNZ096.
     Heat Advisory until 9 PM CDT this evening for MNZ079-086>088-
     094-095.
IA...Extreme Heat Warning until 9 PM CDT this evening for
     IAZ008>011-018-019-029-030.

&&

$$

DISCUSSION...Muscha
AVIATION...Falkinham