Severe Thunderstorm Warning 39, NWS La Crosse, WI

Area Forecast Discussion
National Weather Service La Crosse WI
1255 PM CDT Tue Apr 14 2026

.KEY MESSAGES...

- Strong to severe storms possible today, primarily for the
  southeastern half of the forecast area with large hail,
  damaging winds, a few tornadoes as the primary threats. Heavy
  rainfall leading to flash flooding remains a secondary threat
  with overall fast storm motions expected.

- Storm chances continue through Tuesday night and Wednesday,
  eventually ceasing temporarily through Thursday. Additional
  strong to severe storm chances return Friday
  afternoon/evening/night.

&&

.DISCUSSION...
Issued at 1254 PM CDT Tue Apr 14 2026

Severe Storms Today

If you didn't get a slice of the action yesterday, have no fear
because we're in for another round of potentially higher end severe
weather again today. The main locations under the gun today will be
Northeastern Iowa into SW/Central Wisconsin. An outflow boundary
from last night/this mornings convection is expected to lift north
as an effective warm front. Current guidance is in good consensus
that this will stall out across NE Iowa into Central Wisconsin by
mid-afternoon. Satellite imagery is already showing this boundary
clearly across Central Iowa where skies have cleared early this
afternoon. Convective inhibition will erode through the coming
hours with daytime heating and ascent ahead of a shortwave
upper trough ejecting into the Upper Midwest will support
initiation by mid-afternoon. The airmass will be plenty
unstable with 2000-3000 J/kg of MLCAPE present on area soundings
once the cap finally erodes. Supercells are expected to go up
quickly with steep mid level lapse rates and abundant effective
bulk shear across the region (30-50+ kts). All hazards will be
in play with these storms but the main threats look to be large
to very large hail and a few tornadoes (potentially strong). The
parameter space is thermodynamically supportive of large hail.
Hodographs show a fairly straight, elongated hodograph with a
little bit of low level curvature. Think the best threat for
tornadoes will be along and near the boundary where low level
helicity can be maximized. The supercells are expected to move
quickly off to the east and grow upscale into a more linear
feature where damaging winds will take over as the primary
threat. Luckily, hydro concerns remain limited as storms are
expected to form in areas that didn't see significant rainfall
from yesterday's batch of storms. These storms should also be
moving at a good clip which will limit the impacts of heavy
rainfall in a given area. The environment is certainly favorable
for some significant storms this afternoon and early evening
with the Day 1 Enhanced Risk in place with significant hail and
tornado probabilities in place across southwestern Wisconsin and
northeastern Iowa.

Severe Storm Potential Wednesday

The severe threat for Wednesday will hinge a lot upon how much
the airmass can recover from this afternoon/evening's storms.
The airmass will remain persistently warm and moist as yet
another surface low will move into Iowa, likely putting
southeastern portions of our area in the warm sector - again.
Ongoing showers and storms may inhibit how much we can
destabilize by the afternoon. If we can destabilize and get
enough diurnal heating, the environment would be supportive of
strong to severe storms with around 1000 J/kg of CAPE. Shear
profiles this far north don't look particularly impressive but
low level helicity near the warm front may be enough to support
a low tornado risk. Again, this will depend heavily on lingering
convection tonight and into tomorrow morning with hopefully
better consensus among models with the 00Z and 06Z suites.

Storms Ramp Back Up Friday

After a brief lull in activity for Thursday, we ramp back up into
severe chances for Friday. A deep trough is expected to take shape
over the Rockies late in the week. As this slides east,
southwesterly flow is expected to increase across the area. At the
surface, a bit of a complicated pattern is set to take shape with
two semi-weak surface lows, one over the Northern Plains and
another over the Central Plains. Out ahead of these lows, a
broad warm sector will develop across much of the Mississippi
River Valley. With increasing ascent from the upper trough and
surface lift from a cold front that moves east, a line of
storms is expected to develop sometime Friday west of our area.
Steep mid level lapse rates and a strengthening low/mid level
jet at 40-60 kts will support initial supercell development
before storms form into a QLCS. Thermodynamic profiles show a
broad area of 2000-3000 J/kg across our area with slightly
curved and elongated hodographs. With all of this coming
together, SPC has put our area in a Day 4 Slight Risk with an
Enhanced Risk just off to our south and west, where shear and
overall forcing looks a bit more robust.

Snow Showers This Weekend?

As the aforementioned surface low(s) move off to the north and east
into Ontario by 12Z Saturday, the long draping cold front will have
finally made its way through the area. With the low strengthening
slightly, the pressure gradient will remain tight enough to allow
strong cold air advection into the area early Saturday. While
high temperatures Friday will be in the 70s areawide, highs by
Saturday will have fallen 20-30 degrees into the low 40s to mid
50s. Model guidance is even indicating some the precipitation on
the back side of the low could be a rain/snow mix or just all
light snow. Which is a wild thing to think about after a week of
70+ degree temperatures but such is life in the midwest during
spring. Any snow should not be impactful with no accumulations
expected given that ground temperatures should support melting
on contact.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1228 PM CDT Tue Apr 14 2026

IFR and MVFR ceilings will become VFR by mid-afternoon.

Scattered storms will develop along and south of the Interstate
90 by mid-afternoon and then move south by late afternoon. Some
of these storms could be strong to severe.

Dense fog will develop tonight and continue into the mid-morning
of Wednesday.

&&

.HYDROLOGY...
Issued at 1254 PM CDT Tue Apr 14 2026

Widespread hydrologic concerns are not expected with this
afternoon and evenings activity given the fast expected storm
motion and overall impacted location being south of where the
heaviest rain for yesterday's event has fallen. Given that SW
Wisconsin is under threat, the main basin of concern would be
the Kickapoo as it's notoriously flashy and could see rises into
Action/Minor with this activity.

Flood watches and warnings continue for locations along the
Black and Trempealeau Rivers primarily with other locations
impacted including the Yellow River at Necedah and various spots
along the Wisconsin River. The larger basins seem more at risk
as we move through the rest of the week with continued chances
for rain today, tomorrow, and Friday. None of these events look
to provide particularly heavy rain but the repeated activity
will likely cause river rises along area basins. Flash flooding
is not of great concern either but rain rates with the strongest
thunderstorms may support local ponding.

&&

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

&&

DISCUSSION...Barendse
AVIATION...Boyne
HYDROLOGY...Barendse

Hazardous Weather Outlook
National Weather Service La Crosse WI
129 PM CDT Tue Apr 14 2026

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-
032>034-041>044-053>055-061-152230-
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-
129 PM CDT Tue Apr 14 2026

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

.DAY ONE...This Afternoon and Tonight

Severe thunderstorms are likely this afternoon across northeastern
Iowa and southern Wisconsin with a lesser storm risk further to
the northwest. All storms will be capable of large hail of 2
inches or greater in diameter, damaging winds, and a few
tornadoes. Locally heavy rainfall will be more of a secondary
threat as storms will be moving fairly quickly and shouldn't
linger over any one area for too long.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

The threat for severe weather lingers for Wednesday afternoon and
possibly Friday evening. Uncertainty remains with tomorrow's
activity as ongoing showers/storms tomorrow morning may limit how
strong storms across our area can get. Details on severe weather
for Friday will be refined in the coming days.

.SPOTTER INFORMATION STATEMENT...

Spotter reports may be needed this afternoon and again Wednesday
afternoon.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

Preliminary Local Storm Report
National Weather Service La Crosse WI
528 PM CDT Tue Apr 14 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0525 PM     Tornado          5 E Mount Hope          42.97N 90.76W
04/14/2026                   Grant              WI   Trained Spotter

&&

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Preliminary Local Storm Report
National Weather Service La Crosse WI
533 PM CDT Tue Apr 14 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0515 PM     Hail             Saratoga                43.37N 92.41W
04/14/2026  E2.75 Inch       Howard             IA   Public

            Time estimated via radar.

&&

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Preliminary Local Storm Report
National Weather Service La Crosse WI
534 PM CDT Tue Apr 14 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0534 PM     Hail             Patch Grove             42.94N 90.97W
04/14/2026  M1.00 Inch       Grant              WI   Trained Spotter

&&

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Preliminary Local Storm Report
National Weather Service La Crosse WI
539 PM CDT Tue Apr 14 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0538 PM     Hail             1 SSE Hillsboro         43.64N 90.33W
04/14/2026  M1.75 Inch       Vernon             WI   Public

&&

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Preliminary Local Storm Report
National Weather Service La Crosse WI
543 PM CDT Tue Apr 14 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0540 PM     Hail             1 WNW Harmony           43.56N 92.03W
04/14/2026  M1.50 Inch       Fillmore           MN   Trained Spotter

&&

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Preliminary Local Storm Report
National Weather Service La Crosse WI
555 PM CDT Tue Apr 14 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0555 PM     Hail             6 ENE Wonewoc           43.70N 90.11W
04/14/2026  M1.00 Inch       Juneau             WI   Emergency Mngr

&&