107
FXUS63 KGRB 202337
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
637 PM CDT Sun Sep 20 2026

Updated aviation portion for 00Z TAF issuance

.KEY MESSAGES...

- Hazardous boating and swimming conditions are expected on the
  Bay and Lake at times through Tuesday.

- A quieter and drier weather pattern will settle into the region
  for the next week. Patchy frost will be possible at times
  across the northwoods.

&&

.DISCUSSION...
Issued at 113 PM CDT Sun Sep 20 2026

Minimally impactful weather is expected through next weekend. Mostly
cloudy skies will remain across the region tonight as breezy
northeast wind stream over the relativity warm waters of Lakes
Michigan and Superior, however, with increasing dry air moving in at
mid-levels don`t expect any lake effect rain. A short-wave,
currently over Wyoming, will track east across the mid-Mississippi
and Ohio valleys Monday and Tuesday shutting warm and moist air well
south of the region and allowing a Hudson Bay high to continue
feeding seasonally cool, dry, and stable air into the region. With
that clear skies over night Monday and Tuesday nights may lead to
areas of frost across parts of north-central WI. Temperatures will
begin to trend warmer later into the week with highs return to above
normal by next weekend. Next chance for widespread rain doesn`t look
to arrive until early next week.

&&

.AVIATION...for 00Z TAF Issuance
Issued at 637 PM CDT Sun Sep 20 2026

The stratocumulus cloud deck with high-end MVFR and low-end will
continue to mix/move out of the area this evening. Some lingering
stratocumulus clouds are possible tonight. Additional high-end
MVFR and low-end stratocumulus clouds are expected on Monday. Low
chance (10-20%) of some lower clouds overnight, but will not
include. Otherwise, high clouds will spread across the region
through the TAF period.

Northeast winds will continue to gust to around 20 through early
this evening, highest in eastern WI, then stay mainly under 15 kts
overnight. East to northeast winds are expected on Monday,
gusting to 15 kts.

&&

.MARINE...
Issued at 113 PM CDT Sun Sep 20 2026

Northeast winds will persist through the early part of this week
with passage of a cold front. Gusts from 20 to 30 kts will be likely
at times into Tuesday thanks to a potent high pressure system
keeping a tight pressure gradient over the Great Lakes. A Small
Craft Advisory and Beach Hazard Statement will remain in effect at
least through Tuesday evening.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Beach Hazards Statement through Tuesday evening for WIZ022-040-
050.
&&

$$

DISCUSSION.....GK
AVIATION.......Bersch
MARINE.........GK

NWS GRB Office Area Forecast Discussion