161
FXUS63 KGRB 221744
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1244 PM CDT Sat Aug 22 2026

Forecast discussion for routine afternoon forecast issuance

.KEY MESSAGES...

- Isolated to scattered showers and storms (20-60% chance) north-
  central to eastern WI this afternoon. A strong storm could
  produce gusty winds and hail.

- Dry weather returns Sunday and Monday, with a period of
  unsettled weather arriving for the middle of next week.

- Slightly below normal temps this weekend, then a return to near
  normal readings for most of next week. Lows Sunday night may
  drop into the 30s north-central.

&&

.DISCUSSION...
Issued at 1242 PM CDT Sat Aug 22 2026

Near term through Sunday...Northwest flow and shortwave diving
across this afternoon during peak heating will result in isolated
to scattered showers through 7p, especially far northeast WI and
on across Door County. While weak deep layer shear (less than 25
kts) limits overall storm organization and the severe threat,
MLCAPEs up to 1000 J/kg, inverted-V soundings, very steep low-
level lapse rates, and lower freezing levels will promote some
gustier winds and small hail in the stronger showers/storms.
Northwest winds will be breezy at 15 to 25 mph this afternoon,
before diminishing this evening. Closer approach of sfc high will
bring dry weather tonight into Sunday. Upper trough (cold air
aloft) close enough to lead to another partly to mostly cloudy
afternoon as fair weather cu blossoms. Northwest winds will be a
little lighter on Sunday, but could still gust to 20 mph.

Extended...Dry, but chilly Sunday night with high overhead and low
PWATs allowing for good radiational cooling. MOS guidance already
suggesting that typical cold spots up north could drop into the
mid to upper 30s. Next chance for showers and some storms arrives
Tuesday afternoon through Wednesday afternoon as a sharp mid-
level trough and sfc cold front work through. If cold front is
slower on Wednesday (ECMWF), there would be better chance for a
few stronger storms over eastern WI that afternoon. Instability
appears modest with this mid-week feature, keeping severe risk
low. Machine learning is mixed at best on severe potential. Then,
similar to today post fropa, steeper lapse rates and peak heating
may yield another round of isolated to scattered showers and
storms on Thursday.

Temperatures...After the cooling this weekend into early Monday,
temps return to near or even slightly above normal with highs
mainly in the mid 70s to low 80s. Normal highs for the coming
week start off in the 77-78F range, but by next weekend fall off
into the mid 70s.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1242 PM CDT Sat Aug 22 2026

Expect low end VFR clouds with isolated to scattered showers
primarily impacting northeast to east-central WI. TS potential
there, but timing, location not certain enough to include in TAFs
other than at MTW where a TS is already nearby. Terminals most
favored to be impacted are GRB/ATW/MTW. Only a few lingering
mid clouds are expected after sunset through rest of tonight.
Sunday looks dry, but fair weather cu will blossom by late
morning on into the afternoon.

Northwest winds will gust to 20 kts this afternoon, then ease to
under 10 kts after sunset. Northwest winds may gust again on
Sunday to around 15 kts.

&&

.MARINE...
Issued at 1242 PM CDT Sat Aug 22 2026

Northwest winds of 10-20 kts with gusts to 25 kts expected tonight
into Sunday morning behind re-inforcing cold front. Have hoisted
Small Craft Advisory for the central Bay and for Lake Michigan
nearshore waters north of Sturgeon Bay. Strongest winds will be
near Death`s Door and Washington Island. Offshore winds will
limit waves to 1 to 3 ft for most spots on the bay and nearshore
waters, with any 3-4 foot waves staying in the open waters.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION.....JLA
AVIATION.......JLA
MARINE.........JLA

NWS GRB Office Area Forecast Discussion