Forecast Discussion for GRB NWS Office
020
FXUS63 KGRB 210919
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
319 AM CST Fri Nov 21 2025

Forecast discussion for routine morning forecast issuance

.KEY MESSAGES...

- Quiet with moderating temperatures into early next week.
  Precipitation chances return late Monday through Tuesday.

- Windy and turning colder with snow showers possible Tuesday
  night into Thursday.

&&

.DISCUSSION...
Issued at 319 AM CST Fri Nov 21 2025

A weak cold front was moving through the southern part of the
forecast area early this morning, accompanied only by a narrow
band of low clouds. Temperatures were in the 20s northwest and
30s elsewhere.

Mainly dry weather is anticipated from tonight through Monday
morning. High pressure will reside over the forecast area
today and tonight, and again late Saturday night through Monday
morning. In between, a weak frontal system will move through the
region on Saturday. WAA, mid-level FGEN and a weak short-wave
trough may generate enough saturation for a scattered light mix
of rain/snow near the WI/Upper MI border between 15z-21z/Sat.

Rest of the forecast: The remnants of a Southwest U.S. upper low
will lift northeast toward the Great Lakes, bringing widespread
light rain Monday afternoon into Tuesday. A strong upper trough
or upper low over the Northern Plains will then shift northeast
toward Lake Superior, bringing a mix of rain/snow Tuesday night
into Wednesday, and a chance of snow showers Wednesday night into
Thursday. The best chance of accumulating snow appears to be over
far north central WI, though amounts could vary significantly,
depending on whether wind trajectories are west or northwest.
Northwest flow will be much more favorable for lake-effect,
especially in far north central WI/Vilas County. As this system
pulls out to the northeast, gusty west to northwest winds will
develop, with possible gales developing on Lake Michigan.

Temperatures: Normal to above normal temperatures are expected
through early next week, with a trend toward much below normal
readings mid to late week.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1039 PM CST Thu Nov 20 2025

Main aviation concern for the overnight period will be low cloud
trends as the arrival of drier air continues to break up the
lingering low stratus deck in the region. As a result, lingering
MVFR ceilings will be in the region early on but conditions
should lift to VFR relatively quickly. As a result of the rapid
clearing overnight, brought back in a brief mention of fog for the
central Wisconsin TAF sites in the early morning hours, but would
expect any fog coverage to be fairly patchy and lift shortly after
sunrise. Light winds and clear skies are then expected for
majority of the day Friday.

&&

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

&&

$$

DISCUSSION.....Kieckbusch
AVIATION.......Uhlmann

NWS GRB Office Area Forecast Discussion