153
FXUS63 KGRB 191826
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
126 PM CDT Sat Sep 19 2026

Forecast discussion for routine afternoon forecast issuance

.KEY MESSAGES...

- Widespread showers and a few thunderstorms will continue into
  tonight. Additional rainfall up to 1 inch will be possible south
  of Highway 29, but the threat for widespread flooding has
  diminished as the heaviest rainfall remains anchored further
  south.

- A Beach Hazards Statement and Small Craft Advisory have been
  issued into this evening for areas south of Algoma. Additional
  advisories are also in effect Sunday morning through Tuesday as
  strong northeast winds and high waves develop.

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

&&

.DISCUSSION...
Issued at 126 PM CDT Sat Sep 19 2026

Rest of Today/Tonight: Showers will gradually expand in coverage
this afternoon as a surface low and the right rear quadrant of a jet
streak pass over the region. A few embedded thunderstorms are
possible as well this afternoon, mainly across central WI as
southerly flow south of stalled warm front bring weak elevated
instability to those areas. As the low exits the region tonight
showers will come to an end from north to south with a surge of much
drier air moving into the region.

Quiet weather returns for next week: For the long term period from
Sunday through Friday, a prolonged stretch of quiet and dry weather
is anticipated across north-central and northeast Wisconsin.
Shortwave energy originating from a western trough will slowly
migrate across the central Plains and southern Great Lakes toward
the East Coast during the week, keeping deep moisture and rain
chances suppressed well south of the local area. Strong high
pressure centered over northern Ontario and Quebec will maintain an
expansive plume of dry air across northern Wisconsin, keeping rain
probabilities below 10 percent through Saturday. Under clear to
partly cloudy skies, efficient radiational cooling on Monday and
Tuesday nights will drop overnight low temperatures into the mid to
upper 30s across north-central Wisconsin, leading to patchy frost
formation in low-lying areas. A steady warming trend will take place
throughout the week as afternoon high temperatures rise from the low
and mid 60s on Monday and Tuesday into the low and mid 70s by Friday.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1207 PM CDT Sat Sep 19 2026

Poor flying conditions expected for the rest of the day as low
pressure moves across the region, bringing widespread IFR to LIFR
ceilings, IFR and MVFR visibilities, and periods of rain and
drizzle. There is a 20% chance of thunderstorms this afternoon
mainly south of Hwy 29, but confidence is sufficiently low to
exclude from the forecast.

As low level winds shift to the northeast, improving flight
conditions are expected to return from northwest to southeast
overnight. A return to VFR/MVFR is plausible at all TAF sites,
starting with RHI around 03-05Z and reaching MTW by 09-11Z.

East/southeast winds will be rather steady today, then will shift
to the northeast between 22-02Z. Gusts to 20 kts are expected at
times.

&&

.MARINE...
Issued at 126 PM CDT Sat Sep 19 2026

Gusty southeast winds up to 25 knots ahead of the low will build
waves to 3 to 6 feet along the Lake Michigan shoreline south of
Algoma through this evening. Small Craft Advisory and Beach Hazards
Statement remain in effect through 10 PM. Following a brief lull in
winds and waves late tonight, northeast winds will increase to 15 to
25 knots early Sunday morning following the passage of the surface
low. These strong northeast winds will persist into Tuesday as a
high-pressure system builds across northern Ontario and Quebec,
resulting in building waves of 4 to 8 feet and a high risk of
dangerous rip currents along the Lake Michigan coast. A second Small
Craft Advisory and Beach Hazards Statement have been issued
beginning at 6 AM Sunday and will remain in effect through Monday
and much of Tuesday.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Beach Hazards Statement from Sunday morning through Monday
afternoon for WIZ022.

Beach Hazards Statement until 10 PM CDT this evening for WIZ040-
050.

Beach Hazards Statement from Sunday morning through Tuesday
evening for WIZ040-050.
&&

$$

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

NWS GRB Office Area Forecast Discussion