980
FXUS63 KGRB 011702
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1202 PM CDT Fri Aug 1 2025

Updated aviation portion for 18Z TAF issuance

.KEY MESSAGES...

- Smoke from Canadian wildfires will result in poor air quality
  and reduced visibilities at times into Saturday. An Air Quality
  Advisory is currently in effect until noon today. Part or all of
  the advisory may need to be extended later this morning.

- Patchy fog may restrict visibilities for motorists at times
  early this morning across north-central Wisconsin. Patchy fog
  is possible again late tonight across much of the area.

- Dry weather, cool nights, warm days and low humidity are
  expected through the weekend. The probability of the humidity
  dropping below 35% today ranges from 40-60% along the Michigan
  border. Rain is not expected until the middle part of next week.

&&

.DISCUSSION...
Issued at 359 AM CDT Fri Aug 1 2025

Visibilities have improved across northeast and east-central
Wisconsin overnight as the surface smoke was expected to
dissipate or shift to the west. Across central and north-central
Wisconsin, there was a mix of patchy fog and smoke. It was a cool
morning with readings in the 40s and 50s. The coolest readings at
3 am was Land O` Lakes at 41 degrees. Meanwhile, a light
northeast wind off the relative warmer waters of Lake Winnebago
kept Oshkosh at 65 degrees.

Turning our attention to the smoke, an Air Quality Advisory is
currently in effect until noon today. The 00z HRRR Smoke Graphics
had a pretty good handle on improving conditions across northeast
Wisconsin overnight with some patchy smoke lingering across
north-central and central WI. The HRRR model output has the smoke
expanding south and east again today into tonight and lingers it
into Saturday. Suspect that part or all of the Air Quality
Advisory may need to be extended later this morning. Will wait
for an update from The Wisconsin DNR for the latest information on
any changes to the Air Quality Advisory.

Fair weather cumulus clouds are expected to develop again today
with highs in the middle 70s to near 80. The probabilities of
the humidity dropping below 35% is 40-60% along the Michigan
border. High pressure will remain across the western Great Lakes
into the middle of next week with the next chance for a widespread
rainfall on Wednesday night and Thursday. Did lower minimum
temperatures a few degrees, especially across the north and in
our typical cold spots over the weekend. A fairly large diurnal
swing is expected with cool night and warm days with low afternoon
humidity readings. High temperatures will likely run a few degrees
above normal for much of next week.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1202 PM CDT Fri Aug 1 2025

Relatively good flying weather is expected through the TAF period.

Fair weather cumulus remains on track to develop this afternoon around
6,000 feet before rising to around 8,000 over north-central and
far northeast WI. Fair weather cumulus will develop again late
Saturday morning and afternoon.

Patchy ground fog is expected between 07-12z Saturday, probably
impacting much of north-central and far northeast WI. Confidence
is low whether the ground fog will impact the Fox Valley and
lakeshore areas.

Lastly, surface smoke will drop visibilities at times to MVFR for
much of the TAF period. Confidence is highest that MVFR
visibilities will occur over north-central and far northeast WI.
But some potential that the Fox Valley and Lakeshore areas will be
impacted between 22z Fri thru 13z Sat. Awfully difficult to case
reduced visibilities in smoke so will monitor and amend as
necessary.

&&

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

&&

$$

DISCUSSION.....Eckberg
AVIATION.......MPC