Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 281736

Area Forecast Discussion
National Weather Service La Crosse WI
1236 PM CDT Sat May 28 2022

.DISCUSSION...(Today through Friday)
Issued at 256 AM CDT Sat May 28 2022

Key Messages:

 - Rain chances return today

 - Summery temperatures through the holiday weekend

 - Monday evening/night and Tuesday most favorable for stronger


The remains of the convection that developed Friday evening over the
Dakotas was moving into the western portions of Minnesota early this
morning. This activity is expected to continue moving east on the
nose of a weak low level jet ahead of a short wave trough working
across the region. The RAP and hi-res meso-scale models all show
this activity holding together as it advances east, but dissipating
some and becoming more scattered in coverage. They also show most of
the activity staying north of Interstate 94 with only a couple CAMS
having anything as far south as Interstate 90. Only around 200 J/kg
of MU CAPE for this activity to work with which should be enough to
support a little bit of thunder as it comes across. All of this
should be past the area by the middle of the afternoon at the
latest. Increasing southerly flow will help to start bringing in
some warmer air with highs today reaching the 70s with a few 80s
possible for parts of northeast Iowa and southeast Minnesota.

Sunday through Tuesday...

Active weather sets up to our west again Sunday evening through
Sunday night. A small part of SE Minnesota is barely clipped by an
SPC Slight risk with a tight gradient to general thunderstorms from
west to east across the CWA. The shortwaves bringing strong to
severe weather to the west on Sunday night seem to die out before
they get to the CWA. Showers are possible Sunday night along with a
couple isolated rumbles of thunder. The main impacted area would be
western edges of the CWA. Building ridging in the upper Mississippi
Valley and southerly warm air advection will continue to increase
temperatures. Mostly cloudy skies on Sunday will prevent it from
warming up significantly, though summery temperatures in the 80s are
expected across the area. Winds will also be gusty with much of the
area possibly seeing gusts up to about 30 kts.

More shortwaves Monday night will create more favorable conditions
for stronger storms to form in the area. A closed low system will be
moving west towards the area Monday, with its cold front passing
Monday night. As the front passes, showers are possible for the
area. The best chances for storms would be late afternoon/early
evening Monday, as CAPE values are most favorable then. However,
these higher CAPE values quickly decrease after sunset, thus
decreasing storm chances. With that said, the possibility of strong
to severe storms depends largely on the timing of the frontal
passage. There are still timing differences on this between models
so will have to continue to adjust the forecast. SPC has placed some
westernmost counties in a Slight risk for Monday with an Enhanced
risk just to our west.

This system and its front should linger in the area through Tuesday,
bringing another round of shower chances Tuesday night. There are
model differences in how Tuesday`s chances for rain and storms plays
out. The GFS suggests continuous precipitation chances from Monday
night`s event into Tuesday night, while the EC suggests a break in
the precipitation during the daytime on Tuesday. How this plays out
seems to depend mostly on how the front sets up in the area. Still a
few days out, so will continue to keep an eye on these possible

Mid to Late Week...

Unfortunately all good things (summery temperatures) must come to an
end. An upper-level trough sets up over the area mid-week decreasing
850 mb temperatures, and thus causing cooler surface temps.
Temperatures in the 60s and 70s are expected for the back end of the
week, along with intermittent chances for rain showers.


.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1236 PM CDT Sat May 28 2022

VFR conditions are expected through the TAF period. Showers and
storms have moved off to the east with no sensible weather expected
through tomorrow morning. Gusty winds today continue through mid
afternoon with 30-35 knot gusts west of the Mississippi River and
gusts up to 25 knots east of the Mississippi River. Another gusty
day tomorrow as well. Southerly winds persist through the period.
Low confidence in low level wind shear at the TAF sites overnight.
Models also indicate the possibility of mid level ceilings for a few
hours tomorrow morning. Will monitor these trends closely during
future TAF updates.




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