497
FXUS63 KGRB 111042
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
442 AM CST Wed Nov 11 2026

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Scattered (30 to 50% chance) showers possible Wednesday into
  Thursday.

- Lake effect showers could last through Friday, producing locally
  higher amounts of rainfall over northern Wisconsin and Door
  County with a 30-40% chance of exceeding half an inch of
  rainfall.

- Temperatures will begin to trend cooler Wednesday with near to
  slightly below normal temperatures through this weekend.

&&

.DISCUSSION...
Issued at 1048 PM CST Tue Nov 10 2026

Unsettled weather returns to the region Wednesday as a compact
shortwave crosses the area. The precipitation will generally
arrive in three waves. The initial round will arrive early
Wednesday as weak warm air advection ahead of the shortwave leads
to a region of frontogenesis through the mid to late morning
hours, resulting in an west-east oriented broad area of light
precipitation with around 40-60% chance at any one location across
central to east-central Wisconsin. A break is then possible for
most of the area before additional showers develop along a cold
front that arrives along with the upper shortwave. These showers
will be more cellular, resulting in on and off light rain showers
for much of the region. Would expect the best rain chances to be
associated with the passage of the cold front in the afternoon
and evening. Finally, the third round will arrive as cold air
advection behind the front drives lake effect showers through the
overnight hours and through much of a Thursday. Despite the
presence of rain in the forecast throughout the period, the
overall rain potential will still be relatively light. A
widespread tenth of an inch of total rainfall is expected for most
(50-70% chance), but probability of exceeding a quarter of an
inch is limited to the counties along the Upper Peninsula and
northern Door County. Rain chances then drop to near zero
overnight everywhere but the typical lake effect regions of far
north- central Wisconsin and portions of Lake Michigan shoreline
but especially northern Door County. The continued potential for
lake effect showers will increase rain potential for these areas,
with around 30-40% chance of exceeding half an inch of rainfall
Wednesday through Thursday for north-central Vilas and northern
Door County. Finally, some snow may still mix into the lake effect
showers at times Wednesday night and again Thursday night. While
most will likely not see any of this snow accumulate, the
persistent signal for some lake effect snow showers has kept the
probability of around a half an inch for northern Vilas at around
40-60% chance. Door County may also see a few flurries, but
accumulations there will likely be inhibited by warm ground
surfaces and daytime highs.

Temperatures will see a return to near or slightly below normal
with the influx of cooler air, with highs in the upper 30s to 40s
Thursday and Friday before gradually trending above normal over
the weekend.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 442 AM CST Wed Nov 11 2026

Conditions will slowly deteriorate today as isolated rain showers
develop across the region. There is abundant dry air in the
lowest levels; therefore, it will take a bit to lower conditions
from VFR to MVFR throughout the day. The abundant dry air in
place, along with the lack of substantial forcing, means much of
the TAFs will have PROB30 groups as the rain showers are not
expected to be widespread or last very long in one particular
area. Additional showers are expected to develop and track through
tonight, with the best chances across north-central Wisconsin and
the lakeshore with a boost from the lake effect component given
northerly winds.

Light winds most of today will increase behind the cold front
tonight, with northerly winds of 15 to 25 knots expected.

&&

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

&&

$$

DISCUSSION.....Uhlmann
AVIATION.......Kurimski

NWS GRB Office Area Forecast Discussion