573
FXUS63 KGRB 191124
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
624 AM CDT Wed Aug 19 2026

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Some early morning patchy fog, otherwise quiet weather today,
  then showers and a few storms arrive Thursday afternoon into
  Friday (50-80% chance). A drought busting rain is not expected.

- High temps remain near seasonal norms into the weekend with a
  few cool nights across northern WI.

&&

.DISCUSSION...
Issued at 151 AM CDT Wed Aug 19 2026

Shower/Storm Potential...Next round of organized showers and
storms arrives Thursday into Friday (50-80% chance), as a cold
front and shortwave drop across the state. Initial WAA precip
could arrive late Thursday morning or early afternoon across north
central WI, but higher chances for rain hold off until Thursday
night. Another round of showers/storms is expected on Friday,
especially over eastern WI, as the front crosses the region.
Locally heavy rainfall will be possible with any storm as PWATs
climb to ~1.5" and soundings showing tall/skinny CAPE. However,
this won`t be a drought buster type of event and some spots may
miss out on any appreciable rain. Widespread severe weather is not
expected Thursday night as better instability/forcing remains to
our west. Will need to watch Friday afternoon if the front slows
down a little and we can destabilize, as dewpoints will climb
into the mid to possibly upper 60s ahead of the front. Lingering
showers are possible this weekend as northwest flow sets up across
the Great Lakes. The next chance for showers and storms arrives
early next week with the arrival of another low pressure system
and cold front.

Fog Potential...Light winds and clearing skies will lead to some
patchy fog development across portions of the area early this
morning, especially where the heavier rain fell last evening. The
fog could be dense in a few spots. The fog will linger through
sunrise then burn off. The drier air should hold off fog
development tonight.

Temps & Humidity Levels...High temps will remain pretty close to
seasonal norms this week and into the weekend with highs mainly
in the mid 70s to low 80s. Some cool August nights are expected
across northern WI tonight and again this weekend with lows mainly
in the 40s, with a few upper 30s in the typical cold spots
possible. Less humid air arrives today as dewpoints drop into the
upper 30s to low 50s. Humidity levels will climb on Friday as the
next system moves across the region, then drop off slightly for
the weekend.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 623 AM CDT Wed Aug 19 2026

Any patchy ground fog will burn off by ~13z. Otherwise, VFR
conditions expected the rest of the TAF period. Look for some high
clouds at times today, along with a few daytime cumulus clouds
later this morning and afternoon.

Light and variable winds will become west/northwest 5-10 kts this
morning and afternoon. A lake breeze is forecast to shift winds
to the southeast at MTW this afternoon. Winds will become light
and variable again this evening into tonight.

&&

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

&&

$$

DISCUSSION.....Bersch
AVIATION.......Bersch

NWS GRB Office Area Forecast Discussion