141
FXUS63 KGRB 111146
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
646 AM CDT Mon Aug 11 2025

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Good chance of thunderstorms Tuesday afternoon, with a Marginal
  Risk of severe storms with damaging winds and hail over
  northeast and east central Wisconsin.

- Dry weather and more comfortable humidity arrives mid-week, but
  warmer and more humid conditions along with a chance of storms
  return late in the week.

&&

.DISCUSSION...
Issued at 350 AM CDT Mon Aug 11 2025

A short-wave/MCV brought showers and a few thunderstorms to the
east central and northeast WI early this morning. Otherwise,
overcast conditions were observed, with areas of low stratus and
fog over the western and southern parts of the forecast area.

After the ongoing showers exit far NE WI early this morning,
expect a dry day, with patchy fog dissipating mid-morning,
followed by partial clearing for the afternoon. The sunshine
should boost temperatures into the lower to middle 80s most
locations.

Dry weather should continue into this evening, but a weak short-
wave/MCV may brush through our SE counties and bring scattered
showers and isolated storms to east central WI overnight into
early Tuesday morning. Lows should range from 55 to 60 northwest
to the 60s elsewhere.

Tuesday still looks interesting, as a stronger cold front, short-
wave trough, RRQ of an upper jet, CAPE of 1000-1500 j/kg and much
stronger deep layer shear of 35-50 kts move through northeast WI
during peak heating. Coordinated with SPC to add a Marginal Risk
of severe storms for the region Tuesday afternoon. SPC HREF
neighborhood probabilities of 30+ knot wind gusts have a bullseye
of 30-50 percent over far NE WI late Tuesday afternoon, and
forecast soundings show an inverted-v profile. This doesn`t look
like a high-end event by any measure, but would expect we will
need to issue a few warnings.

After the cold front moves through Tuesday night, Canadian high
pressure will bring drier and more comfortable weather for
Wednesday and Thursday. As the high shifts east late in the week,
more humid air returns, along with the chance of thunderstorms.
The greatest chances will occur in conjunction with a slow moving
front that pushes through over the weekend. It is possible that
the front will shift far enough south on Sunday to allow for a
dry day in northern WI, but will leave that detail for future
forecasts.

Smoke Trends: There are indications that elevated smoke may
return to the region this afternoon, with patchy near-surface
smoke brushing through the northwest part of the forecast area
tonight into Tuesday. However, smoke concentrations do not look
as significant as the previous couple events, so will hold off on
any specific mention of smoke in the forecast for now. The threat
may increase as the Canadian high moves in mid-week.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 639 AM CDT Mon Aug 11 2025

Showers were exiting far NE WI at issuance time, with widespread
low clouds and patchy fog reported across the rest of the region.

Fog will mix out by 13z-14z, and ceilings will either rise or
break up as the morning progresses, with VFR conditions returning
by 16z-18z. SCT cumulus clouds are expected for the afternoon.

A weak upper disturbance will bring a chance of showers and
possibly an isolated storm to east central WI late tonight,
otherwise dry conditions are expected.

West winds will pick up this morning, then back to the southwest
again later this afternoon and evening.

&&

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

&&

$$

DISCUSSION.....Kieckbusch
AVIATION.......Kieckbusch