461
FXUS63 KARX 160551
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1251 AM CDT Thu Jul 16 2026

.KEY MESSAGES...

- Main forecast concern continues to be wildfire smoke causing
  unhealthy to hazardous air quality through tonight into
  Friday morning for the northeastern half of the local forecast
  area from southeast Minnesota into southwest and central
  Wisconsin.

- Low confidence (<25%) in precipitation potential today with
  heavy rain as the main concern should and where storms form.

- Precipitation chances return mainly in Wisconsin Friday night
  into Saturday and Sunday night into Monday. Current overnight
  diurnal timing limits storm strength and potential.

&&

.DISCUSSION...
Issued at 1251 AM CDT Thu Jul 16 2026

Precipitation Potential Today:

As the northerly, dry and smoke contaminated air sags south through
northern Wisconsin, the more moist air mass lingers across the
southwestern half of the forecast area. While meager, a low level
stretching axis will potentially cause precipitation similar to
Wednesday. While high resolution model solutions suggests higher
confidence, associated soundings limit any instability and overall
upper level saturation. Storm strength will also be limited as shear
values remain insignificant. Heavy rainfall will be likely should
and where storms form as PWATs remain quite moist near 1.5".

Wildfire Smoke & Air Quality Concerns Through Today:

Main forecast concern continues to be poor air quality from Canadian
wildfire smoke mainly from southeast Minnesota into southwest and
central Wisconsin. Current forecast confidence for smoke impacts to
continue through Friday morning, eventually lifting northeast with a
slight change in the change in the synoptic pattern. Alleviation may
be short lived as an upper level perturbation drags southeast
through southern Canada, potentially advecting another, more
transient, bout of poor air quality. Minnesota Air Pollution Control
Agency expanded the Air Quality Alert in southeast Minnesota based
on record poor air quality observations through Wednesday night.

Precipitation Potential Into Early Next Week:

The Upper Mississippi River Valley remains on the periphery of the
quasi-Rex block centered over the Great Plains through the weekend,
permitting synoptic mid to upper level perturbations to pass along
northwest flow causing precipitation potential (GEFS/EPS/GEPS).
Initial chances Friday night into Saturday currently remain confined
locally to counties in central Wisconsin may require further
southwestern brushing of PoPs depending on extent and strength of
anticyclonic flow and higher heights over the southwest. While
current overnight timing limits instability (GEFS/EPS) and therefore
overall storm potential, later advection to this wave into Saturday
would also raise more widespread storm concerns. Similar, limited
confidence for subsequent synoptic wave into early next week
(GEFS/EPS).

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1251 AM CDT Thu Jul 16 2026

Smoke from Canadian and northern Minnesota wildfires continues
to fill in across the region. With the light winds at the
surface and in the lowest 10kft of the atmosphere, the smoke has
settled into many locations and will not leave due to the
inversions forming. KLSE already has visibilities of 2SM from
the smoke and other locations upstream are in the 1 to 4SM
range. These lowered visibilities will continue through the
night and gradually expand southwestward into most of southeast
Minnesota, all of southwest Wisconsin, and portions of northeast
Iowa as the smoke slowly moves southwestward. There is a wind
shift this evening that will help the smoke leave the region.
There is also a low chance (10 to 25%) for showers and storms
across the region this afternoon and evening, however with the
smoke overhead, this may limit storm potential.

&&

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

&&

$$

DISCUSSION...JAR
AVIATION...Cecava