Special Weather Statement, NWS La Crosse, WI

Area Forecast Discussion
National Weather Service La Crosse WI
119 PM CDT Thu Apr 23 2026

.KEY MESSAGES...

- Showers and storms currently over western Minnesota and Iowa
  move into our area this afternoon and overnight. Some storms
  could be strong to severe. Rainfall amounts of 0.5 to 1 inch
  are expected, locally up to 2 inches.

- Temperatures cool to near normal Friday through early next
  week. Highs in the 60s and lows in the 40s are expected.

- Another round of showers and storms looks likely (70-90%)
  Sunday night through Monday.

&&

.DISCUSSION...
Issued at 115 PM CDT Thu Apr 23 2026

Tonight - Friday Morning: Showers and Storms

Showers and storms currently over western Minnesota and Iowa
shift eastward through the region this evening and overnight
along a cold front. Ahead of the front, isolated storms are
possible across our area through the afternoon hours along a
ribbon of 850hPa moisture transport. There's some uncertainty
whether these storms can develop at all as HRRR/RAP soundings
depict warm air in the mid-levels resulting in capping
inversion. However, the moisture transport is able to saturate
this layer, thunderstorm development is favored. Storms that
develop would pose a threat for hail up to 1 inch owing to steep
mid-level lapse rates of 7-8C/km and SBCAPE of 1500-2000 J/kg
per the 23.13z RAP although storms in this environment will be
short lived as 0-6km bulk shear is weak at best, so very little
residence time will occur for hail to grow bigger than this.

As the front moves through the region, the ongoing convection
is expected to maintain itself owing to forcing from the front
as well as MUCAPE of 1000-1500 J/kg. The linear to quasi-linear
mode will continue as 0-6km shear remains weak, mostly locked up
in the lower levels. Because of this, damaging winds are the
primary threat along this line, although if any bowing segments
develop and are able to orient perpendicular to the 0-3km shear
vector, they run the risk of a weak tornado developing given
curvature in the 0-1km layer per model hodographs.

Apart from the strong/severe storm threat, heavy rainfall is
expected across the region as the storms move through the
region. PWATS of 1.2-1.3 inches continue to be depicted in high-
resolution guidance, well above the 90th percentile of
climatology. Decent probabilities for rainfall amounts over 1
inch remain in the 23.12z HREF, sitting around 30-60% with some
signal for up to 2 inches. Overall expectations are for amounts
generally 0.5-1 inches with localized areas up to 2 inches,
most favorable over northeast Iowa and north-central Wisconsin
per the 23.12z HREF 24hr LPMM. Widespread flooding is not a
concern at this point, but ponding is expected in low-lying
areas and rises on rivers in smaller basins where the heaviest
rainfall occurs.

Overall, all severe hazards are on the table this afternoon and
evening through two rounds of storms, although significant
severe potential is not expected given the messy storm mode.
Severe potential is highest west of the Mississippi River with
the initial onset and wanes with eastward extent overnight as
instability decreases. The front and showers/storms move east
of our area around 3am Friday.

Friday - Sunday: Cooler Temperatures and Dry

Cold air advection behind the front brings temperatures closer
to normal for this time of year, with highs in the 60s and lows
in the 40s. Lows may be able to fall into the 30s north of I-94
Friday night into Saturday morning given clear skies and drier
air shifting southeastward with the 23.13z NBM suggesting an 20-
40% chance to fall below 37F. Given vegetation is beginning to
green up across the region, some concern for plant damage from
frost exists during this timeframe.

A weak shortwave at 500hPa moves across the eastern
Dakotas/western Minnesota early Saturday morning with the CAMs
beginning to suggest some precipitation may be observed with the
feature. While the shortwave is currently shown to stay west of
our area, if it shifts further east, some light precipitation
may occur for those west of the Mississippi River, although dry
air in the subcloud layer would act to hinder precipitation
from reaching the surface. Outside of this outlier precipitation
potential Saturday, the coming weekend will largely be
characterized by dry weather.

Sunday Night - Monday: Additional Showers and Storms

The next event for showers and storms comes Sunday night into
Monday as a 500hPa trough ejects into the central Great Plains,
developing a surface low that lifts northward into the Upper
Midwest on Monday. Confidence in rainfall is high at this point
with the bulk of deterministic and ensemble guidance in
agreement with this low moving northward into our area. The
23.00z LREF paints 70-90% probabilities for measurable rainfall
in our area Monday and even has a signal for 1 inch or greater
at 10-20%. The 23.13z NBM depicts a similar scenario with
70-90% probabilities for measurable precipitation and 30-50%
for 1 inch or greater.

The main uncertainly regarding the system is the track of the
parent shortwave and surface, which have shifted considerably
northward in the last 24 hours. This brings the low more
directly overhead the Upper Mississippi River Valley, resulting
in the warm sector of the cyclone into our area. As such,
instability has increased across our area with MUCAPE now on the
order of 1000-1500 J/kg depicted in the deterministic guidance.
The new track also brings the attendant 500hPa jet streak
overtop of the region as well, acting to increase 0-6km bulk
shear, which sits at 30-40kts assuming a surface based parcel,
although little shear exists in the 3-6km layer which would lead
to difficulty sustaining updrafts, similar to today. This
current set-up is favorable for strong to potentially severe
storms Monday, although perhaps not ideal. The SPC highlights
portions of northeast Iowa and southwest Wisconsin in a 15%
probability for severe weather on Day 5 which is also shown in AINWP
convective guidance. All this said, while details will be
ironed out over the weekend, this will be a period to watch as
the new week approaches.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 115 PM CDT Thu Apr 23 2026

Ceilings in the 2-4kft range exist across the region this
afternoon which will continue to lower towards the 1-3kft range
late this afternoon into the evening as a cold front current
located over western Minnesota/Iowa moves eastward. Winds will
remain out of the south ahead of this front with gusts of
20-35kts continuing as it approaches.

Isolated showers and thunderstorms are possible this afternoon
ahead of the front as well (30-50%), but confidence in coverage
is not high enough to include as predominant groups in the
TAFs. Higher confidence in thunderstorms comes around 00z as
the cold front moves into eastern Minnesota/Iowa, moving into
eastern Wisconsin after 08z. Visibilities will be reduced in
rainfall, down to IFR in the heaviest rainfall. After the front
moves east of the area, northwest winds set up for Friday with
skies clearing from west to east.

&&

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

&&

DISCUSSION...Falkinham
AVIATION...Falkinham

Hazardous Weather Outlook
National Weather Service La Crosse WI
419 AM CDT Thu Apr 23 2026

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-
032>034-041>044-053>055-061-241330-
Mitchell-Howard-Winneshiek-Allamakee-Floyd-Chickasaw-Fayette-
Clayton-Wabasha-Dodge-Olmsted-Winona-Mower-Fillmore-Houston-
Taylor-Clark-Buffalo-Trempealeau-Jackson-La Crosse-Monroe-Juneau-
Adams-Vernon-Crawford-Richland-Grant-
419 AM CDT Thu Apr 23 2026

This Hazardous Weather Outlook is for portions of southeast
Minnesota...northeast Iowa and southwest into central Wisconsin.

.DAY ONE...Today and Tonight

Strong to severe storms possible this evening and into the
overnight with damaging winds being the primary threat.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

No action needed.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

Special Weather Statement
National Weather Service La Crosse WI
501 PM CDT Thu Apr 23 2026

MNZ096-WIZ041-232230-
Houston MN-La Crosse WI-
501 PM CDT Thu Apr 23 2026

...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN HOUSTON AND CENTRAL
LA CROSSE COUNTIES THROUGH 530 PM CDT...

At 501 PM CDT, Doppler radar was tracking a strong thunderstorm over
La Crosse, moving northeast at 40 mph.

HAZARD...Wind gusts up to 40 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor hail damage to vegetation is
         possible.

This strong thunderstorm will be near...
  La Crosse, La Crescent, Onalaska, La Crosse Airport, and French
  Island around 505 PM CDT.
  West Salem around 510 PM CDT.

Other locations impacted by this storm include Irish Hill, North Side
Of La Crosse, South Side Of La Crosse, The Valley View Mall, Blue
Bird Campground, County Roads M And W, Highway 33 And Losey
Boulevard, Barre Mills, Nathan Hill, and Veterans Memorial Park.

This includes Interstate 90 in Wisconsin between mile markers 2 and
15.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4389 9101 4373 9125 4372 9126 4375 9133
      4398 9120
TIME...MOT...LOC 2201Z 213DEG 34KT 4379 9124

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH

Falkinham