691
FXUS63 KGRB 071051
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
551 AM CDT Mon Sep 7 2026

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Next chance of rain and storms (60-80%) late Monday night
  through late Tuesday night. Strong storms are possible Tuesday
  evening and night.

- High waves will bring an increased risk of rip currents at Lake
  Michigan beaches Tuesday into Wednesday morning. A Beach Hazards
  Statement is in effect from 9 AM Tuesday to 7 AM Wednesday.

- Gusty winds and high waves will bring hazardous conditions for
  small craft Tuesday into Wednesday morning. A Small Craft
  Advisory is in effect.

- Another period of hazardous conditions for small craft are
  possible Wednesday afternoon due to gusty west winds.

- Temperatures at or above normal continue into the weekend.

&&

.DISCUSSION...
Issued at 215 AM CDT Mon Sep 7 2026

One more tranquil day is in store with partly sunny skies with
highs in the upper 70s to lower 80s. For tonight, clouds will be
on the increase with a chance of showers and isolated
thunderstorms across the north. Instability is meager, thus severe
weather is not expected. Showers and isolated thunderstorms will
move across the area Tuesday morning, continuing into the
afternoon. The latest model guidance is considerably lower on the
instability late Tuesday afternoon and Tuesday night, generally
with CAPE values of 400 to 800 J/KG. 0-6km shear values of 30-40
knots. Bufkit soundings indicated low level winds of 30-40 knots
Tuesday night to support strong gusty winds with any storm.
Wetbulb zero heights fairly high, which is a concern for the
potential for large hail. Main concern will be the ongoing showers
and isolated storms Tuesday afternoon and how that will affect
convection into the evening. The latest Day 2 Outlook has a
Marginal Risk (Level 1 of 5) for much of the area north and west
of the Fox Valley. Showers and storms will come to an end late
Tuesday night.

Dry conditions expected Wednesday into Friday. The next chance
of showers and storms at times will be from Friday night
through the weekend. Confidence is low on timing and placement
of convection due to the various model solutions. High
temperatures at or above normal through the weekend.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 548 AM CDT Mon Sep 7 2026

Some spotty MVFR VSBYs due to light fog should burn off
by 14-15z. Otherwise VFR conditions continue through
tonight. The next chance of showers and storms arrive
late tonight across the north and across the entire area
on Tuesday. Stronger storms are possible Tuesday night.
The rain should taper off late Tuesday night.

&&

.MARINE...
Issued at 215 AM CDT Mon Sep 7 2026

Gusty southerly winds and building waves has prompted the issuance
of a Small Craft Advisory. For the bay, it is in effect from 1 PM
Tuesday to 3 AM Wednesday. For Lake Michigan, it is in effect
from 10 AM Tuesday to 7 AM Wednesday. After a break in the gusty
winds and high waves Wednesday morning, another period of
hazardous conditions for small craft are possible Wednesday
afternoon with gusts of 25-30 knots which may prompt another
Small Craft Advisory during this time frame.

At Lake Michigan beaches, there is an increased risk of rip
currents. A Beach Hazards Statement is in effect from 10 AM
Tuesday to 7 AM Wednesday.

&&

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

$$

DISCUSSION.....Eckberg
AVIATION.......Eckberg
MARINE.........Eckberg

NWS GRB Office Area Forecast Discussion