NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 180445
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1045 PM CST Tue Feb 17 2026

Updated aviation portion for 06Z TAF issuance

.KEY MESSAGES...

- Widespread precipitation arrives late this evening and continues
  through Wednesday morning. A wintry mix of snow, sleet and
  freezing rain is expected across northern Wisconsin, with mainly
  rain farther south. A Winter Weather Advisory is in effect for
  parts of north central and far northeast Wisconsin, where
  hazardous travel is expected. A combination of very wet snow
  accumulations and gusty winds may lead to tree damage and
  sporadic power outages in far northeast Wisconsin.

- Snow is possible area-wide late Thursday into Friday, with a
  20-60% probability of at least 2" of snow, mainly west and
  north of the Fox Valley.

&&

.DISCUSSION...
Issued at 256 PM CST Tue Feb 17 2026

As mentioned in an earlier update, there were no changes to the
areal coverage of the Winter Weather Advisory, but the start time
was delayed until 9 pm (slower arrival time and warm surface
temperatures in the early evening), more sleet and a little less
freezing rain accumulations (warm layer aloft generally 2 C or
cooler over most of northern WI, so only partial melting expected),
and greater snow accumulations near the Upper Michigan border
(little or no warm layer aloft). The highest accumulations of 4-6
inches of concrete snow in northern Forest, Florence and northern
Marinette counties could lead to some tree damage and sporadic
power outages.

Fairly impressive system arrives tonight and lingers through at
least Wednesday morning, with PWAT values in the 97th-99th
percentile and strong forcing associated with WAA on the nose of a
40-50 kt low-level jet, a couple well-defined frontogenetic bands,
several short-waves and the approach of a warm/occluded front.
The forcing appears to come in two waves, one at precip onset
in the mid to late evening, and another stronger band moving
through late tonight into early Wednesday. In between these
two periods of stronger lift, there could be a brief lull and
perhaps some mid-level drying, and this could actually be the
best time period for light freezing rain development in N WI.
Otherwise, snow and sleet look to be the dominant p-types over
the Northwoods. There are several models that still show
significantly higher snowfall amounts over the far north, and
EFI/Shift-of-Tails values show potential for a significant snow
event near the WI/MI border, so subsequent shifts will need to
watch out for that possibility. Rain will be the dominant p-type
along and south of Hwy 29, with little or no snow/ice accums
expected there.

Vertically stacked low pressure remains to our northwest later
Wednesday into Thursday, so light precipitation (mainly snow)
will remain over the northwest part of the forecast area.

A Colorado low is expected to lift northeast into the western
Great Lakes Thursday night into Friday. While the timing looks
similar with the models, the track is very much in question at
this time. Probabilistic forecasts show a 30 to 60 percent chance
of 2+ inches of snow west and north of the Fox Valley. Less snow
is indicated from the Fox Valley east towards Lake Michigan, due
to a greater potential for rain, especially early in the event.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1039 PM CST Tue Feb 17 2026

A mix of light rain and snow has made it to the western TAF sites
late this evening as low pressure approaches from the west.
Accompanying the precip are thickening and lowering cigs, with
most terminals set to drop into IFR territory within an hour or
two of this forecast issuance. Steady rain continues throughout
most of the TAF period, with RHI expected to see periods of snow,
sleet, and freezing rain. A brief window for improvement to VFR
conditions is then possible late Wednesday morning and Wednesday
afternoon for areas south of RHI as an occluded front lifts north.

Winds increase out of the east tonight, gusting between 25 and 35
knots before veering to west/southwesterly Wednesday afternoon.
LLWS continues to progress from west to east overnight as winds
increase to around 50 to 55 knots at 2k ft, diminishing from south
to north mid-morning Wednesday.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until noon CST Wednesday for WIZ005-
010>013-019-021.
&&

$$

DISCUSSION.....Kieckbusch
AVIATION.......Goodin