671
FXUS63 KGRB 250713
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
213 AM CDT Tue Aug 25 2026

Forecast discussion for routine morning forecast issuance

.KEY MESSAGES...

- Periods of showers and storms today through Wednesday evening.
  Greatest potential (40-60%) for widespread chances overnight.
  Low risk of severe weather, mainly late this evening in north-
  central and central WI.

- Next chance for unsettled weather arrives this weekend.

- Gusty south/southwest winds will generate hazardous conditions
  for small craft and dangerous swimming conditions along Lake
  Michigan this evening through Wednesday morning.

&&

.DISCUSSION...
Issued at 213 AM CDT Tue Aug 25 2026

Precipitation Trends...Periods of showers and thunderstorms are
anticipated from late this morning through Wednesday evening. For
late this morning into this afternoon, a weak 850mb jet and
increasing WAA will drive the potential for isolated showers and
storms (25-35%) mainly across the Northwoods. Later this evening
through late tonight, chances for showers and storms increase to 40-
60% spreading across the entire forecast area as a cold front sweeps
across the area. During the late evening (after 9 PM), there appears
to be a small window for a few stronger storms to move into north-
central and central WI. Surface instability and deep-layer shear
will be greatest northwest of the area and will be waning as the
storms move eastward into the forecast area. However, cannot rule
out the potential for the ongoing convection to produce damaging
wind gusts and hail in central and north-central WI before
weakening. The strong/severe storm potential will decrease a few
hours after 9 PM as the storms become elevated. Additional showers
and non-severe storms are possible Wednesday, mainly during the
afternoon, as the surface cold front`s mid-level shortwave trough
moves overhead. By Wednesday evening, probabilities for 0.50 inch or
more of precip range between roughly 20-40% mainly across the
Northwoods and Door County, with less than 10% elsewhere, but would
still expect a few localized areas to receive closer to an inch of
rain under the stronger convection.

After Wednesday, dry weather is anticipated for the remainder of the
work week with the next chances for showers and storms arriving
sometime this weekend. Will need to monitor for the severe weather
potential as the pattern may favor this solution on one of the days
somewhere across the Midwest, but there are timing and placement
differences that will need to be resolved until then.

Temperatures...Throughout the week and into the weekend,
temperatures, both highs and lows, will hover around normal. Highs
will mainly be in the 70s to low 80s, with lows generally in the 50s
to low 60s, but locations across the Northwoods could see lows in
the 40s Thursday night into Friday morning.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1048 PM CDT Mon Aug 24 2026

High pressure will remain over the region overnight. Mainly VFR
conditions are expected with only mid and high clouds present
above 12 kft. Patchy ground fog is possible over far northeast WI,
but probabilities of impacts at the TAF terminals is very low.

Clouds increase on Tuesday as a warmer and more humid airmass
move in ahead of a cold front. Ceilings should generally remain
above 3.5 to 4 kft, but broken conditions are likely at times.
Guidance produces scattered showers in the afternoon, mainly
affecting RHI. Timing of these showers is rather difficult to pin
point, but kept a prob30 at RHI after 20Z Tue. Timing will need
to get refined in later forecasts.

A greater chance of showers and thunderstorms will arrive on
Tuesday evening. Greater potential for impacts at RHI/AUW/CWA than
the eastern WI terminals. Gusty winds and IFR visibilities will be
possible in the heavier downpours.

Southwest winds will increase on Tue with gusts 15-20 kts in the
afternoon.

&&

.MARINE...
Issued at 213 AM CDT Tue Aug 25 2026

A period of persistent south/southwest winds is expected this
afternoon into Wednesday. Winds will gust to 25 kts, with waves
building to 2 to 4 ft with some 5 foot waves possible mainly along
the Lake Michigan nearshore waters. As a result, a Small Craft
Advisory has been issued from 6 PM this evening to 4 AM Wednesday
from Sheboygan to Sturgeon Bay, and 8 PM this evening to 11 AM
Wednesday from Sturgeon Bay to Washington Island. These conditions
will also result in a high swim risk at Lake Michigan beaches.
Beach Hazards Statements have been issued for Manitowoc, Kewaunee,
and Door County.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Beach Hazards Statement from this evening through Wednesday
morning for WIZ022.

Beach Hazards Statement from this evening through late tonight
for WIZ040-050.
&&

$$

DISCUSSION.....Kruk
AVIATION.......MPC
MARINE.........Kruk

NWS GRB Office Area Forecast Discussion