369
FXUS63 KGRB 100352
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1052 PM CDT Mon Mar 9 2026

Updated aviation portion for 06Z TAF issuance

.KEY MESSAGES...

- Very warm with record highs this afternoon for many locations.

- Windy with a mix of rain, freezing rain, sleet and snow
  developing Tuesday into Tuesday night, changing to all snow on
  Wednesday. Snow and ice accumulations are likely. Greatest
  potential for snow over northern WI. Hazardous travel Tuesday
  night into Wednesday.

- Windy with rain and snow Thursday night into Friday. Chances for
  accumulating snow increasing over northern WI. Wintry system for
  the weekend could produce moderate accumulating snow over the
  entire area.

- Runoff from recent rainfall and warmer temperatures will lead to
  elevated river levels early this week.

&&

.DISCUSSION...
Issued at 131 PM CDT Mon Mar 9 2026

After our very warm day today with record highs in many locations,
the weather turns much cooler and active this week into next weekend
with three distinct systems bringing mainly wintry impacts. A few
mid clouds around into this evening, and a few flurries late
tonight over far north-central. Otherwise, into tonight will be a
more benign period compared to the rest of the week.

Lead system arrives late Tuesday as mid-level trough along the
west coast shifts across the northern Plains. Strongest 700-500mb
speed max stays southeast, so heaviest QPF and greatest risk for
thunder should remain on nose of low-level jet into central Great
Lakes. Coupled upper jets and right entrance of jet over northern
Ontario and MN will support swath of mixed precip over the
forecast area, with snow over far north. Bulk of the snow occurs
late Tuesday and more so Tuesday evening into Wednesday morning.

Complicating matters are hints of transient fgen that may be
interacting with developing low-level moisture to produce either
snow or a mix of rain/drizzle/snow as early as Tuesday morning.
Greatest chances for this would across central to north-central/far
northeast WI. As it stands now, sfc temps should be warm enough to
preclude any freezing rain/drizzle, but near term trends for temps
late tonight will have to be monitored. But, given how warm temps
are today and associated road temps will be if there is any mixed
precipitation on Tuesday morning, imagine impacts would be minimal.

Probabilities of 2" and 4" of snow have steadily increased
over the far north in the last few days, while probability of at
least a coating of ice now stands at 50-70% on southern edge of
the snow, from central to east-central WI. Morning commute on
Wednesday will be impacted, though marginal temps falling to the
lower 30s by late Tuesday night from the Fox Valley to the
lakeshore (and associated warmer road temps) could mitigate
impacts there. Higher spread is still present with snow amounts
over the north (25th percentile 2-3" with 75th percentile 5-6") as
models show there could be sharper southern edge to heaviest
snow. Fortunately where the heaviest snow occurs, it appears the
winds/gusts will not be strong, so where only snow occurs mostly
travel impacts due to snow covered and slushy roads. Overall looks
like advisory event for much of the forecast area.

Next clipper type system brings another round of moderate snow to
especially northern portions of the region late Thursday into
Thursday night. Spread quite high with 25th to 75th percentile
ranging from 2 inches to 8 inches. Current probability of 4+
inches of snow sits around 40-50% over northern WI. Given the
high-end potential and some models very wrapped up with sfc-850mb
low, narrow band of heavy snow could occur with an enhanced fgen
band. Still too early for the details though. Does seem that ptype
with this system will be rain or snow, no real freezing precip.
Also, similar to the system Tuesday night into Wednesday, seems
greatest potential for accumulating snow remains over northern WI.
Just ahead of the low and behind it on Friday, winds could be
gusty.

Beyond this system the active weather continues through next
weekend. Good signal that leading edge of stronger system arriving
Saturday night through Sunday will bring band of fgen forced snow
to western Great Lakes on Saturday in right entrance of 500-300
speed max sliding across the Great Lakes. Still differences in
track of sfc low and resulting north-south orientation of max
QPF/heavy snow for Saturday night through Sunday. Early look, but
signals from EFI/WSSI-p point to higher impact winter system. So
to do NBM 50th percentile 24hr snow ending at 00z Mon and
probabilities of seeing 6" for this event. Also, though on the
lower side probabilities for seeing north of 10" are still
pretty high (up to 40%) given the time horizon we`re looking at.
Additional impact is there from blowing and drifting given the
winds/gusts tied to the strong sfc low passing to our southeast.
Trends will be monitored as the energy that develops this system
is still cresting the ridge to the north of Alaska today, but we
are already going to start messaging this system (and the late
week one) to our partners given the signals that are already
showing up.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1052 PM CDT Mon Mar 9 2026

VFR conditions expected overnight with some high and mid clouds
approaching from the west. Lighter precip starts to develop
Tuesday morning, but the main rain/snow does not arrive until
Tuesday evening. Some periods of light snow, or a rain/snow mix
will be on and off in central into northern WI from late Tuesday
morning through the afternoon. Cloud bases will gradually lower as
well, with MVFR cigs moving in from west to east through the
afternoon. More widespread rain and snow arrive Tuesday evening,
with snow primarily across northern WI. An area of freezing rain
is also expected from central into northeast or east-central WI,
but exactly where this sets up is still uncertain.

Winds around 5-10 kts early tonight become NE with gusts to
around 20 knots overnight. Winds continue from the NE on Tuesday
with gusts increasing to 25 to 30 knots. Some LLWS develops late
Tuesday afternoon.

&&

.CLIMATE...
Issued at 131 PM CDT Mon Mar 9 2026

Record highs are in jeopardy of being broken today, March 9.
Here are the current record high temps:

Antigo: 52 in 1930,1966,2025
Appleton: 61 in 2021,2025
Green Bay: 60 in 2025
Manitowoc: 60 in 2025
Marshfield: 62 in 2021
Merrill: 60 in 1977
Oshkosh: 68 in 1956
Rhinelander: 57 in 1977
Stevens Point: 63 in 1987
Sturgeon Bay: 55 in 2025
Wausau: 60 in 2021
Wisconsin Rapids: 68 in 1987.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION.....JLA
AVIATION.......KLJ
CLIMATE........Kieckbusch/JLA

NWS GRB Office Area Forecast Discussion