Special Weather Statement, NWS La Crosse, WI

Area Forecast Discussion
National Weather Service La Crosse WI
232 PM CDT Wed Aug 3 2022

.DISCUSSION...(This evening through Wednesday)
Issued at 232 PM CDT Wed Aug 3 2022

Key Messages:

 - Storm chances into this evening

 - Fog potential tonight

 - Precipitation chances return over weekend

Storm Chances - This Afternoon

The CAMs continues to show that there will be scattered showers and
storms along the cold front as it moves southeast through the
region. With the best forcing over Wisconsin, kept the higher rain
chances there. With the effective shear generally less than 30
knots, not expecting any of the storms to produce organized severe
weather. With downdraft CAPES in the 1000-1200 J/kg, might see some
isolated, short-lived strong gusty winds with any collapsing cores.

Tonight - Fog Potential

High pressure will build across the region. Due to the combination
of clear skies and decreasing winds in the boundary layer, there
will likely be some valley fog in the Wisconsin and Mississippi
River tributaries. With falling dew points, still plenty of
uncertainty on how of this fog will get into the main channel of the
Mississippi.

This Weekend - next round for showers/storms

Broad upper-level ridging builds over the region
heading into the weekend. Surface temperatures will be on the
increase as warm air advection increases over the area in
conjunction with winds increasing from the south. Both the NAEFS
and ECMWF ENS have 850 mb temperatures over 2 to 2.5 standard
deviations above the model climatology. Saturday afternoon is
currently anticipated to be the warmest of the next several days
with temperatures in the upper 80s to low 90s. With dewpoints
pushing into the 70s, this would result in heat indices nearing
100 mainly across portions of northeast Iowa, far southwest
Wisconsin, and the typically warmer areas along the Mississippi
River Valley and the nearby/immediate tributaries. However, this
is still highly dependent on precipitation arrival times. The
highest chances (50-70%) are anticipated overnight Saturday into
Sunday with only a small subset of the 03.12z GEFS (10%) would
have precipitation for portions of the forecast area by early
Saturday evening.

The overall pace of the surface front could be fairly slow and may
even stall out, so that would also play into how soon showers/storms
enter and eventually exit the area. With this lower confidence on
the progression of the boundary, precipitation chances linger (30-
40%) over the area through Sunday night. It is too early to
confidently determine the risk for severe storms, but at this time
cannot completely rule out the potential for some stronger storms.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1249 PM CDT Wed Aug 3 2022

High pressure will build across the area into tonight. Skies
should gradually clear KLSE early this afternoon and remain sunny
for KRST.

Due to the combination of clear skies and decreasing winds in the
boundary layer, there will likely be some valley fog in the
Mississippi River tributaries. Still plenty of questions on
whether it will impact KLSE, so kept the TAF fog free for now.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&

DISCUSSION...Boyne/Peters
AVIATION...Boyne

Hazardous Weather Outlook
National Weather Service La Crosse WI
449 AM CDT Wed Aug 3 2022

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-
032>034-041>044-053>055-061-041400-
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-
449 AM CDT Wed Aug 3 2022

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

.DAY ONE...Today and Tonight

Scattered storms will be possible today until a cold front ushers
in drier air.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

More storms are possible this weekend. It's too early to discern
if there would be a severe risk.

.SPOTTER INFORMATION STATEMENT...

No action needed.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

Zapotocny

Special Weather Statement
National Weather Service La Crosse WI
341 PM CDT Wed Aug 3 2022

IAZ011-WIZ054-032115-
Allamakee IA-Crawford WI-
341 PM CDT Wed Aug 3 2022

...A strong thunderstorm will impact portions of central Allamakee
and western Crawford Counties through 415 PM CDT...

At 341 PM CDT, Doppler radar was tracking a strong thunderstorm near
Lansing, moving southeast at 15 mph.

HAZARD...Winds in excess of 40 mph and penny size hail.

SOURCE...Radar indicated.

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

This strong thunderstorm will be near...
  Lansing around 355 PM CDT.

Other locations impacted by this storm include Thompson Corner, Elon,
Red Barn Campground, Churchtown, Village Creek, Dalby and Eldergrove.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4336 9144 4343 9128 4330 9103 4320 9135
TIME...MOT...LOC 2041Z 324DEG 11KT 4338 9129

MAX HAIL SIZE...0.75 IN
MAX WIND GUST...40 MPH

Skow