661
FXUS63 KGRB 080459
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1059 PM CST Fri Nov 7 2025

Updated aviation portion for 06Z TAF issuance

.KEY MESSAGES...

- Turning colder this weekend with high temperatures ranging from
  the upper 20s to middle 30s by Sunday.

- Most locations will have potential to see their first snowflakes
  of the season this weekend.

- Accumulating lake effect snow of 1 to 3 inches is expected
  across far north- central WI from Saturday night through Sunday
  night. The probability of receiving two inches of snow or
  greater ranges from 50 to 80% over Vilas county.

- Conditions will be hazardous to small craft on the Bay and Lake
  at times over the next week.

&&

.DISCUSSION...
Issued at 230 PM CST Fri Nov 7 2025

A low-pressure system east of Lake Superior is dragging a cold
front across southern Wisconsin to northern Iowa this afternoon.
In the colder airmass behind the front, widespread low stratus
clouds are present, with bases lowering from 4500 ft to 1000-2000
ft (sub-1000 ft in some areas). Light showers or sprinkles are
moving across southwest and central Wisconsin. Patchy drizzle or
sprinkles are also occurring over north-central WI. The scattered
showers may reach the Fox Valley later this afternoon. Increasing
instability over Lake Superior could bring light rain and snow to
far northern Wisconsin at times, impacting Rhinelander and
reducing visibility, through the evening.

Brief drying is expected late this evening and overnight, with
partial clearing in central to northeast Wisconsin. Some models
suggest an inverted trough developing by Saturday morning,
bringing low- level clouds back to the AUW/CWA area, with bases
above 3500 ft, though confidence is low.

A clipper system will move across the northern Plains to the mid-
Mississippi Valley on Saturday. While most precipitation stays
south, decent saturation over central to east-central Wisconsin
could lead to flurries or light snow (under 30-60% chance) on
Saturday afternoon. Otherwise, expect mostly cloudy conditions
with possible flurries or light snow showers over Vilas County,
with minimal accumulations.

LONG TERM (Saturday Night through Next Thursday):

An anomalously deep upper trough will bring a winter-like pattern
to the Great Lakes Sunday and Monday, with below-normal
temperatures persisting throughout much of the week.

Potential for light snow and flurries will continue over northeast
WI on Saturday evening before ending. Perhaps a tenth or two of
accumulations will be possible.

Favorable thermodynamics and northwest winds on Saturday night
will lead to lake effect snow showers off western Lake Superior
into north-central Wisconsin, intensifying briefly with shortwave
passage. Expect short periods of intensified lake effect bands on
Sunday morning and also Sunday night, with equilibrium levels of
11000 ft, delta ts of 22 Celsius, and 850-700mb relative humidity
near 95%.

Lake effect ingredients will ebb and flow through Monday,
limiting overall snowfall. Northern Vilas County has an 80% chance
of over 2 inches of snow, decreasing rapidly south of the county.
Accumulations near Lake Michigan have been lowered.

A light rain/snow mix is possible Monday night within a brief warm
advection regime, with minor snow accumulations in the far
northeast. Gusty winds will necessitate small craft advisories on
Green Bay and Lake Michigan at times over the next week. High
temperatures will be in the 30s and 40s, near to below normal.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1058 PM CST Fri Nov 7 2025

Some flurries will remain possible across central and north-
central WI overnight into early Saturday. Look for am mix of
mainly MVFR/VFR conditions overnight as downsloping northerly
winds, along with some drier air advecting in brings a period of
mostly clear skies to GRB/ATW/MTW (and for a time to AUW/CWA). Any
gusts this evening will diminish, with winds remaining under 10
kts overnight into Saturday.

MVFR and VFR conditions will continue for most of Saturday with
any breaks in the clouds filling back in as a clipper system
approaches from the west. The area will see a glancing shot of
light snow and flurries, mainly at ATW/MTW, where a dusting of
snow is possible. A few lake effect flurries will remain possible
at RHI as well.

&&

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

&&

$$

DISCUSSION.....MPC
AVIATION.......Bersch