735
FXUS63 KARX 132341
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
641 PM CDT Thu Aug 13 2026

.KEY MESSAGES...

- Widespread rain ending this morning, but additional showers
  and storms are expected later tonight into Friday. Latest
  trends continue to show the heaviest rain will fall south of
  the area near I-80.

- Periods of showers and storms will return Friday
  evening/night, but taper off through the weekend. Localized
  heavy rain and flooding are possible, but the overall severe
  potential remains low.

- Flooding Risk bears watching through the rest of the week,
  especially across northeast Iowa, but with storms expected to
  set up south of the area, the greatest risk will be across
  central Iowa and Illinois.

&&

.DISCUSSION...
Issued at 1115 AM CDT Thu Aug 13 2026

TODAY THROUGH TONIGHT...Early morning satellite and radar
imagery together with surface obs showed a textbook Mesoscale
convective system (MCS) with a nearly symmetric cloud shield
and expansive footprint of precipitation. As of 11am, the back
of this precipitation was clearing I-35, and this trend will
continue to the east the rest of the morning into the early
afternoon.

Looking ahead, the chance for rain to redevelop later today and
this evening is low, so do have precipitation chances dropping
from near 100 percent this morning, to roughly 40 percent later
today.

The risk for severe weather is low with storms, as the weak
surface low will allow the cold pool to remain across the
region, and the lack of strong synoptic forcing means the
instability to the south won`t be advected northward. Similarly,
the threat for flooding rain will be south of the region as
well, closer to the higher instability, where rainfall rates
will be greatest due to convection.

In summary, there is a non-zero chance for flooding and severe
weather, but SPC maintains the Marginal risk to the south, and
the HiRes Guidance trends shown via the 13.12Z HREF have the
heaviest rainfall near I-80 in central Iowa.

FRIDAY THROUGH SATURDAY...The boundary responsible for this
repeated rounds of thunderstorms will move very little. It may
oscillate slightly northward during the day, but then get pushed
southward as the cold pool develops from overnight convection.

This remains the case for Friday into Saturday. There are
chances for thunderstorms in the forecast, but the higher
chances are to the south. The only difference is the upper level
ridge shifts eastward a bit, meaning there is some southwest
component to the upper level jet. This could push the storms a
bit farther north as compared to tonight`s placement.

Again, the risk for severe weather is low, with heavy rain and
localized flooding as the primary threat.

SUNDAY THROUGH WEDNESDAY...No major changes from the previous
forecast. Weak high pressure builds across the region as the
upper level jet becomes northwest oriented once again. The
highest probability for thunderstorms remain across central
Iowa, but predictability is lower in this set up as light winds
remain in place the the surface features are subtle at best.
Temperature remain seasonal, with highs near 80, and lows near
60.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 640 PM CDT Thu Aug 13 2026

Scattered showers and maybe a thunderstorm will be found north
of Interstate 90 this evening. Another band of showers and
storms will affect areas south of Interstate late this evening
and overnight.

Ceilings and visibilities will be IFR/MVFR south of I-90 late
this evening and overnight. Otherwise, they will be VFR.

$&

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

&&

$$

DISCUSSION...MPX
AVIATION...Boyne