356
FXUS63 KGRB 041120
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
520 AM CST Wed Feb 4 2026

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Light snow/wintry precip arrives late Wednesday night, lasting
  through Friday morning. Greatest chances for 1 inch of snow are
  across northern Vilas and northern Door.

- Temperatures to read above normal on Thursday, with some areas
  of central Wisconsin seeing a chance at above freezing highs.

- Below normal temperatures return over the weekend.

&&

.DISCUSSION...
Issued at 113 AM CST Wed Feb 4 2026

Precip chances... Not many changes in the track of the clipper
low from previous forecast cycles, with ensembles taking the
brunt of the system to our north. Big picture still shows two
rounds of precip developing in conjunction with this system, the
first of which arrives early Thursday morning in tandem with a
swath of WAA preceding cold FROPA. This will bring a widespread
shot of isentropically-driven light snow across northeast
Wisconsin, in what looks to be a high PoP low QPF scenario as
saturation deepens the further south of the UP border you go.
Remain rather pessimistic on the potential for any rain mixing in
across central Wisconsin during this time, as the warmer near-
surface layer remains shallow and only marginally freezing. Cold
front and secondary shortwave then arrive early Friday morning,
bringing another round of light wintry precip across the forecast
area. Tried to provide resolution in the PoPs between the two
waves where possible. Overall, LREF grand ensemble still shows a
strong (50 to 60%) signal for 1 inch of snowfall over the lake
effect belts of northern Vilas and northern Door. However, main
concern during this time will be the potential for freezing
drizzle mixing in as drier mid levels sit atop a shallow layer of
supercooled water (0 to -5C) at/near the surface. Have once again
taken the approach of limiting NBM ZR wx type to ZL. This may
result in travel impacts to the Friday morning commute, mainly on
untreated roads or surfaces.

Temperatures... Near normal temperatures over the majority of the
week will give way to a brief period of above normal temperatures
on Thursday, with highs peaking in the low to mid 30s for most.
Greatest chance (50 to 70%) for above freezing highs will be over
central Wisconsin, with the only hindrance being remnant cloud
cover from the departing clipper. A surge of colder air behind
said low then arrives later on Friday, tanking highs into the
upper teens and 20s across the area by Saturday afternoon. This
being said, conditions then moderate to (well) above normal by the
start of the next work week.

Winds... Winds ramp up out of the northwest Friday morning as the
pressure gradient tightens up along the cold front, resulting in
area-wide surface gusts to 25 mph. Low-end gales will be possible
on Lake Michigan Friday afternoon, mainly up near Death`s Door.
Regardless, prevailing northerly winds within strong CAA regime
will lend some confidence to at least high-end small craft
conditions.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 448 AM CST Wed Feb 4 2026

VFR conditions should prevail for the majority of the TAF period.
Some CAMs try to show low MVFR and even IFR lake effect stratus
developing over the far north later this morning through the
afternoon, though remain pessimistic about whether lower cigs will
make it down to RHI. Otherwise, BKN to OVC stratus and light snow
move in from the northwest by around 10 to 12Z Thursday. Light winds
start out of the west/northwest, backing to southwesterly by
Thursday morning.

&&

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

&&

$$

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

NWS GRB Office Area Forecast Discussion