357
FXUS63 KGRB 201129
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
629 AM CDT Wed Aug 20 2025

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Patchy dense fog expected through daybreak, especially central
  and north-central Wisconsin.

- Isolated showers are possible at times today, especially east-
  central Wisconsin and the lakeshore. The rest of the week will
  be dry with the next chance for showers and thunderstorms Friday
  afternoon into Friday night. Severe storms are not expected.

- Temperatures will be around normal for much of the upcoming
  week, with the potential for well below normal temperatures late
  in the weekend into early next week.

&&

.DISCUSSION...
Issued at 255 AM CDT Wed Aug 20 2025

Very patchy fog across the region early this morning should burn
off shortly after sunrise. A weak shortwave trough embedded in
northwest flow will bring a small chance (10-20%) for light
showers or sprinkles today across east-central Wisconsin and the
lakeshore.

High pressure will then keep the region dry tonight through Friday
morning. A cold front will bring the next chance for showers and
thunderstorms to the region Friday afternoon and Friday night as
it tracks through the western Great Lakes region. NWP models are
not all that bullish on QPF amounts as this cold front tracks
through the area, as the best dynamics will be to the north. The
potential for severe storms looks fairly low as instability looks
to stay below 1000 J/kg with around 20 knots of bulk shear. A
strong storm cannot be ruled out during peak heating, but that
looks to be the extent of the severe potential at this time.

Behind the cold front a much cooler airmass will push into the
region as daytime highs go from the 70s to around 80 to the 60s to
around 70 or about a 10 degree tumble in daytime highs for the
weekend and into early next week.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 629 AM CDT Wed Aug 20 2025

Very patchy fog should lift in the next few hours; however, lower
ceilings will persist through the morning with a slow improvement
to MVFR/VFR through the afternoon. Fog will again be possible late
tonight after midnight into Thursday morning with IFR/LIFR
conditions possible, especially west and north of the Fox Valley.

&&

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

&&

$$

DISCUSSION.....Kurimski
AVIATION.......Kurimski