NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 150238
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
938 PM CDT Sat Mar 14 2026

New Information added to update section

.UPDATE...
Issued at 920 PM CDT Sat Mar 14 2026

No changes were made to the headline timing or coverage this
evening, and only minor changes were made to the snowfall ranges
in the WSW product.

The biggest uncertainty in the forecast still hinges on how strong
and how far north the the warm layer aloft gets late tonight into
Sunday, as this will significantly impact precipitation type and
the amount of snow that occurs over central and east central WI.
If the warm layer pans out as currently predicted, there will
copious amounts of sleet (perhaps over an inch in some locales)
and up to a couple tenths of an inch of ice. If the warm layer
stays south, snowfall totals will need to be increased for areas
south of Hwy 29.

Blizzard conditions are still looking like a good bet, especially
over the Fox Valley and lakeshore areas Sunday night into Monday
morning.

UPDATE
Issued at 634 PM CDT Sat Mar 14 2026

Radar showed a large band of precipitation extending from central
MN into central WI, in response to increasing mid-level WAA/
isentropic lift and FGEN. This precipitation was not yet reaching
ground in WI, but RH timesections suggested this would occur
around 8 pm in our southwest counties, spreading to NE WI by
midnight.

The snow is expected to become heavy later tonight into Sunday,
especially along and north of Hwy 29, where the SPC HREF supports
snowfall rates as high as 1-3 inches/hour. These higher rates
arrive 08z-09z/Sun in NC WI, and depart far NE WI by about
21z/Sun. Models offer differing opinions on the strength and
extent of the warm layer aloft, but the general consensus is that
it will mainly affect our southern two tiers of counties, bringing
a mix of sleet, freezing rain and rain (far south/southeast)
before eroding in the afternoon/early evening.

No significant changes expected for the headlines this evening,
but may make a few tweaks after I dig into it a bit more.

&&

.KEY MESSAGES...

- A historic winter storm will impact the region tonight through
  Monday. Heavy snow, mixed precip, and strong winds will create
  blizzard conditions as well as widespread and significant
  impacts across the area, including extremely difficult travel
  and power outages. Snowfall totals of 15 to 30 inches with
  locally higher amounts. Winter Storm Warnings and Blizzard
  Warnings have been issued.

- Sleet and/or freezing rain will likely mix with snow at times
  across east-central Wisconsin, resulting in the potential for
  0.1 to 0.2" of ice accumulation on Sunday. Precip then
  transitions back to all snow Sunday night.

- Below zero wind chills will be possible on Monday, moderating
  back to near normal throughout the week.

- Next chance of light snow (60-80%) is on Tuesday night into
  Wednesday.

&&

.DISCUSSION...
Issued at 315 PM CDT Sat Mar 14 2026

Historic snowstorm arrives this evening, and will be the largest
since April 13-15, 2018, and then should continue into Monday
afternoon. The calm before the storm this afternoon with partly
cloudy skies far north and mostly cloudy elsewhere. Temperatures
were in the 30s.

Latest model runs from this morning indicated the snow was a
little slower to arrive this evening, thus pushed back the start
time of the warning across the southern half of the forecast
area by an hour or two. Across the north, pushed up the start
time by a few hours. Snow is expected to develop across central
and east-central WI in response to an fgen band that sets up
across the area. This band shifts northward late tonight into
Sunday morning. Late tonight, models indicating a warm layer
between five and nine thousand feet. This warm layer would support
sleet up to Green Bay and possibly Wausau. The warm layer is warm
enough that the precipitation will change over to rain, sleet or
freezing from Wautoma to Oshkosh to Manitowoc late tonight into
Sunday afternoon. Current forecast has a tenth or two of ice from
Waushara County east to Manitowoc County.

For locations to the north, snow will continue Sunday. Increasing
winds and heavy snowfall will lead to blizzard conditions. Have
issued a Blizzard Warning from 15z Sunday to 20z Monday. For the
Fox Valley, the Blizzard Warning will start at 21z Sun until the
risk of the mix precip ends and at 00z for Manitowoc and Kewaunee
counties. The low should pass to the east of the area Sunday
night, resulting in strong wind and blizzard conditions. Gusts of
40 to 60 mph are likely resulting in damage to trees and power
lines which results in expected power outages. Another concern
will be for much colder air to work into the region Sunday night
which will result in the snow to become powdery and more easily
blown around across central and east-central WI. Snowfall totals
may rival and may be higher than the April 2018 storm. Current
forecast has 13 to 32 inches of snow, with the lowest totals
across the southern Fox Valley. Highest totals were across
Marinette and Oconto counties. NBM probabilities were a staggering
70-90 for two feet of snow.

Decided to continue the Blizzard Warning through 4 pm Monday
until the stronger winds subside despite the heavier snow
ending. Previous events with the powdery snow has resulted in
reductions in visibilities and problems on roads due to accidents
or slide offs. Visibilities will remain poor into the afternoon.

Some lingering light snow continues into the evening across the
far north Monday evening. Another clipper system will bring a
chance of light snow Tuesday night and Wednesday. It is too early
to determine snowfall amounts. Fairly tranquil conditions are
expected the rest of the week with seasonable spring temperatures.

&&

.AVIATION...for 00Z TAF Issuance
Issued at 634 PM CDT Sat Mar 14 2026

Deteriorating flight conditions will occur this evening, with
conditions becoming quite dangerous for flight operations late
tonight into Sunday. Flight delays/cancellations will occur, and
airport closures may be needed at times Sunday into Monday.

Thickening/lowering clouds and virga were observed across the
region at issuance time. Snow is expected to develop around 8 pm
in our southwest counties, spreading into far NE WI by around
midnight. Heavy snow will spread across NC/NE (along and north of
Hwy 29) late tonight (after 08z/09z/Sun) and continue in far NE
WI until around 21z/Sun. Farther south, a warm layer aloft will
bring a wintry mix of snow, sleet, freezing rain and rain starting
late tonight and continuing into Sunday afternoon.

E winds will increase later tonight into Sunday morning, then
really start to crank up as they become NE-NW Sunday afternoon
into Monday. Gusts to 35 to 45 kts are likely due the height of
the storm. LLWS arrives overnight into early Sunday and continues
most areas through the day.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning until 10 AM CDT Sunday for WIZ005-010>013-
021-022-073.

Blizzard Warning from 10 AM Sunday to 4 PM CDT Monday for WIZ005-
010>013-018>022-030-031-035>037-045-073-074.

Winter Storm Warning until 10 AM CDT Sunday for WIZ018>020-030-
031-035>037-045-074.

Winter Storm Warning until 4 PM CDT Sunday for WIZ038-039-048-
049.

Blizzard Warning from 4 PM Sunday to 4 PM CDT Monday for WIZ038-
039-048-049.

Winter Storm Warning until 7 PM CDT Sunday for WIZ040-050.

Blizzard Warning from 7 PM Sunday to 4 PM CDT Monday for WIZ040-
050.
&&

$$

UPDATE.........Kieckbusch
DISCUSSION.....Eckberg
AVIATION.......Kieckbusch