Winter Weather in Wisconsin, December 28, 2021

Area Forecast Discussion
National Weather Service La Crosse WI
1130 AM CST Tue Dec 28 2021

.SHORT TERM...(Today and tonight)
Issued at 352 AM CST Tue Dec 28 2021

Clouds have continued to thicken overnight. As a result,
temperatures have stabilized and started to rise. Temperatures as
of 3 AM ranged from 5F at Medford WI to 24F at Platteville, WI.

The 28.00z models are showing less precipitable water and moisture
transport into the Upper Mississippi River Valley for today. As
result, precipitation amounts were lowered by 1 to 2 tenths of an
inch across the area. This resulted in a reduction in the expected
snow amounts across the area today. It now looks like much of the
area will see 1 to 3 inches of snow.

HREF suggest that the hourly snowfall rates may approach an inch
between 10 AM and 1 PM this afternoon west of the Mississippi
River, between 1 PM and 3 PM in southwest and west-central
Wisconsin, and between 3 PM and 5 PM in central and north-central
Wisconsin. These higher rates are tied to a band of strong
700-500 mb frontogenetic moving northeast through the region.

There continue to look like there may be some elevated
instability and steep mid level lapse rates late this morning and
early afternoon. This may result in some elevated convection.

Soundings continue to show that there will be a loss of ice aloft
during the mid afternoon which will result in a transition from
snow into freezing drizzle across southeast Minnesota and
northeast Iowa, during the late afternoon in southwest and west-
central Wisconsin, and in the evening in central and north-central
Wisconsin. This freezing drizzle will likely continue into the
evening for most locations.

Due to the mix of snow and freezing drizzle, a Winter Weather
Advisory remains in effect for today and this evening. The only
change this morning was to extend the end time of the advisory for
the counties along the Mississippi and Wisconsin rivers from 6 PM
to 9 PM.

.LONG TERM...(Wednesday through Monday)
Issued at 352 AM CST Tue Dec 28 2021

On Wednesday, there is better agreement among the 28.00z models
that there will be a band of strong 700-600 mb frontogenesis
across parts of northeast Iowa and southwest Wisconsin. Due to
this, the snow chances were increased. With limited moisture, snow
amounts look to be less than an inch.

On New Years Day, there is less phasing between the northern and
southern streams. As a result, the surface low is much weaker and
its track has shifted further to the southeast. As a result, the
GEFS and ECWMF EPS are generally showing less snow across the
region. In addition with the southward shift, there still some
uncertainty on how far this snow will get. This is especially the
case north of Interstate 94. Due to this, snow chances were kept
low.

It continues to look like the coldest weather for the winter so
far will occur this weekend. While there is still decent spread in
the high temperatures, the spread in the low temperatures continue
to decrease. High temperatures will be in the single digits and
teens. While we currently have low temperatures in the single
digits below zero on Sunday morning, the ECMWF EPS suggests that
our low temperatures will be likely in the 10 to 20 below range.
If we do get this cold, we might see our first wind chill advisory
for the 2021-22 winter. The last time we issued one was February
15, 2021.

After a bitterly cold weekend, temperatures moderate for early
next week with high temperatures in the 20s and 30s.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1130 AM CST Tue Dec 28 2021

Main taf concerns are IFR/LIFR conditions and freezing drizzle at
both taf sites this afternoon and into this evening. Surface low
tracking across the Central Plains States will continue to spread
light snow/freezing drizzle into the area this afternoon and into
this evening. LIFR conditions are expected for periods of this
afternoon and possibly into early this evening at both RST/LSE taf
sites...due to reduced visibilities from the snow or freezing
drizzle. Ice accumulations of less than a tenth of an inch is
expected. Conditions will improve to VFR tonight after 07z at both
taf sites.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Winter Weather Advisory until 9 PM CST this evening for WIZ032-
     033-041-053>055-061.

     Winter Weather Advisory until midnight CST tonight for WIZ017-
     029-034-042>044.

MN...Winter Weather Advisory until 6 PM CST this evening for MNZ086-
     087-094-095.

     Winter Weather Advisory until 9 PM CST this evening for MNZ079-
     088-096.

IA...Winter Weather Advisory until 6 PM CST this evening for
     IAZ008>010-018-019-029.

     Winter Weather Advisory until 9 PM CST this evening for IAZ011-
     030.

&&

SHORT TERM...Boyne
LONG TERM...Boyne
AVIATION...DTJ

Hazardous Weather Outlook
National Weather Service La Crosse WI
433 AM CST Tue Dec 28 2021

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-
032>034-041>044-053>055-061-291200-
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-
433 AM CST Tue Dec 28 2021

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

.DAY ONE...Today and Tonight

A Winter Weather Advisory is in effect. 1 to 4 inches of snow
are expected along with a glaze of ice.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Wind chills will range from 15 to 25 below on Sunday morning.

.SPOTTER INFORMATION STATEMENT...

Snow and ice reports would be appreciated.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

Boyne