Forecast Discussion for GRB NWS Office
870
FXUS63 KGRB 091922
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
222 PM CDT Fri Oct 9 2026
Forecast discussion for routine afternoon forecast issuance
.KEY MESSAGES...
- Unseasonably warm and windy conditions are expected this weekend with
inland high temperatures into the upper 70s to middle 80s.
- 50-60% percent chance for rain across the region Monday
afternoon and evening. A few rumbles of thunder are possible.
- Another 60-70% chance for widespread rain late next week with
much cooler temperatures arriving next weekend.
&&
.DISCUSSION...
Issued at 220 PM CDT Fri Oct 9 2026
There is a low-end (10-15%) chance for a few isolated showers to
develop across east-central WI this evening as a mid-level warm
front lifts northward. Otherwise expect dry and quiet conditions for
the rest of the day. Saturday strong warm advection and deep mixing
will bring unseasonably warm and windy conditions to the region.
High temperatures are forecast to reach the low 80s across most of
the region except along the lakeshore where highs will be capped in
the low 70s. Southerly winds will increase Saturday morning with
sustained winds reaching 15-20 mph during the afternoon and wind
gusts up to 30-35 mph. As the PBL decouples Saturday evening and
the pressure gradiant begins to slack off winds will gradually
weaken Saturday night into Sunday. While Sunday won`t be as breezy
the warmth will stick around with highs in the upper 70s to
middle 80s, warmest in central WI.
Monday will see the next chance for area wide precipitation with
NBM probs showing a 50-60% chance for rain Monday afternoon and
evening as a cold front pushes across the region. Depending on
timing of the cold front there is a low-end chance (~5%) for a few
isolated thunderstorms during the afternoon as weak instability
builds ahead of the front. However, at this point the risk for
severe storms is very low. QPF looks limited with this event as
medium ranged ensembles show less than a 30-40% chance for greater
than 0.1 inches of rain through Tuesday morning across the
forecast area. Another more widespread chance for precipitation
may comes during the middle to end of next week as global
ensembles show a deepening low pressure system lifting across the
western Great Lakes. Still a lot of uncertainty with the details
of this system, but this looks like the best chance for a soaking
rain over the next 7-10 days.
&&
.AVIATION...for 18Z TAF Issuance
Issued at 1240 PM CDT Fri Oct 9 2026
VFR conditions are expected through this TAF period. High based
clouds will continue to filter over the region through Saturday
morning. Ahead of an approaching warm front, a surge of low clouds
will move across the area from the southwest to northeast after 23z
Fri with cloud bases around 5-6kft AGL. These low clouds will exit
the region around 10-12Z.
Winds are shifting to the southeast around 5-10 kts this afternoon.
A brief period of LLWS is possible after 05z this evening as south
winds of 35-40 kts are anticipated above the southeast surface winds.
&&
.MARINE...
Issued at 220 PM CDT Fri Oct 9 2026
Southerly winds are forecast to increase tonight and remain gusty
through the weekend. Waves are expected to build to 4-9 ft on Lake
Michigan from tonight through Saturday night. South winds to 30 kts
are possible on Saturday and Saturday night. Small craft advisories
will be in effect tonight through at least Sunday morning.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....GK
AVIATION.......GK
MARINE.........GK
NWS GRB Office Area Forecast Discussion