204
FXUS63 KGRB 060729
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
229 AM CDT Sun Jul 6 2025

Forecast discussion for routine morning forecast issuance

.KEY MESSAGES...

- Seasonal summer weather is expected over the next week. Shower and
thunderstorm chances (50-60%) return Monday night and Tuesday, risk
of severe storms is low (less than 10%).

&&

.DISCUSSION...
Issued at 229 AM CDT Sun Jul 6 2025

Today...

Main focus for this morning is any fog development as skies begin to
clear out across northern WI. With yesterday`s rain there is plenty
of low-level moisture and surface obs show winds have become calm
across most of the region. Fog is most likely to develop in north-
central WI where clouds are stating to erode. A few sites in
northwest WI have been reporting fog for several hours. Think this
fog may spread into Vilas and parts of Oneida counties with lower
confidence the fog spreads further south and east. Any fog that does
develop should burn off fairly quickly this morning.

A cold front continues to slowly sag southeastward toward southern WI
early this morning. This will keep light scattered showers going
across eastern WI through mid-morning. Ridging then begins to build
in from the west returning dry weather for the remainder of the day.
Temperatures will be about 10 degrees cooler than yesterday with
highs this afternoon reaching the low 70s to low 80s. Humidity will
also be noticeably lower today as dew points fall into the middle
50s to low 60s across the region.

Behind the front northerly winds will be breezy this afternoon,
particularly along the lakeshore with winds 10-15 mph gusting up to
25 mph at times. The increasing winds may make for choppy waters
along Lake Michigan, but though conditions were too borderline to
justify a Beach Hazard or Small Craft Advisory.

Work Week Forecast...

Temperatures this week are forecast to trend near normal with highs
in the upper 70s to middle 80s each day. Humidity will also be lower
as dew points sit in the upper 50s to low 60s for much of the week.

Ridging will continue to build over the western Great Lakes Monday
keeping the region dry. Global ensembles show the ridge beginning to
break down during the middle of the week as several weak short-waves
move through the upper-level flow. Fist of these waves is progged to
pass over northern WI Monday night returning shwith the timing and
intensity of any storms.ower and storm chances (30-50%) through
Tuesday. Instability and available moisture are not expected to be
all that impressive (400-600 J/kg SBCAPE and 1.4-1.5" PWATs), so
think the risk for any severe storms is very low (less than 10%)
Tuesday. Another short-wave arriving later in the week may bring
another round of showers and storms Friday into next weekend.
Ensembles show a slightly more favorable environment for stronger
storms during this period, but there remains a great deal of
uncertainty with the timing and intensity of any storms.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1058 PM CDT Sat Jul 5 2025

Showers and isolated storms will continue through the late
evening and overnight hours, especially across eastern WI, as a
cold front moves across the region. Lightning and torrential rain
will be the main threats from the storms. MVFR and possibly IFR
ceilings are expected overnight into Sunday morning, with partial
clearing through the day. Some daytime cu is possible where the
clearing occurs in the late morning and afternoon. If any clearing
occurs overnight, some fog would likely develop.

Southwest to west winds will shift to the north behind the cold
front overnight, with north/northeast winds on Sunday. Gusts to
~20 kts are expected.

&&

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

&&

$$

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