NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 042300
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
600 PM CDT Mon May 4 2026

Updated aviation portion for 00Z TAF issuance

.KEY MESSAGES...

- Warm and breezy through early this evening with low relative
  humidities and elevated fire weather conditions.

- Wind gusts 35 to 40 mph expected across central to eastern
  Wisconsin through early this evening.

- A line of showers and thunderstorms (20-30% chance) could
  develop late this afternoon across the southern Fox Valley and
  lakeshore. Stronger storms could produce wind gusts 40-50 mph.

- Temperatures fall below normal for the rest of the week. Risk
  for Frost/Freeze Headlines ramps up beginning Tuesday night.

&&

.DISCUSSION...
Issued at 1251 PM CDT Mon May 4 2026

Breezy and warm conditions are expected through early this evening
as a cold front continues moving through the region. CAMs show a
thin line of showers and thunderstorms developing across the far
southeastern portion of the area, including the southern Fox
Valley east to the lakeshore. However, much of the area should
for the most part escape unscathed with no rain from this cold
front. In fact, the recent CAMs runs develop this line just
outside of our area or just the extreme southeastern portion of
our area. Therefore, lowered POPs a notch with the highest amount
only 30% instead of 40% given the lower probability of seeing rain
from this front. If storms do develop, inverted-V soundings
indicate gusty winds of 40-50 mph will be possible. Given the
synoptic winds are already gusting to 30 to 40 mph, it won't take
much to push winds just a bit higher. Any activity would quickly
move southeast out of the area; therefore, the window for this
isn't particularly large and only a few hours.

Gusty winds will continue this evening behind the cold front and
slowly subside throughout the night. Winds should die down below
20 mph sometime around or shortly after midnight.

Cooler weather is then expected for the rest of the week with
temperatures just below normal for this time of year. Daytime
temperatures will mainly be in the 50s, with 40s closer to the
lakeshore. The cooler temperatures will bring the risk for
Frost/Freeze potential during this period, with the highest
potential Tuesday night through Thursday night. Temperatures will
then rebound to around normal for this time of year by the
weekend, with a low risk for additional Frost/Freeze headlines.

Conditions are expected to mainly be dry for the rest of the
week; however, there will be small (10% chance) for an isolated
shower Tuesday and Wednesday as shortwaves rotate around the upper
level trough located across the Great Lakes region. There is a
better chance (20-30%) for showers on Thursday as a more vigorous
shortwave dives southeast with a bit more moisture in the column.
Mainly dry conditions are then anticipated late in the week into
the early part of the weekend, with a low (10-20%) chance for
showers late in the weekend.

&&

.AVIATION...for 00Z TAF Issuance
Issued at 600 PM CDT Mon May 4 2026

Early this evening, a cold front is exiting the NE WI lakeshore.
Scattered showers and storms continue to develop south and east of
KMTW, but lighter activity north to Washington Island is likely
no intense than just sprinkles. Winds continue to gust from 20 to
30 kts across the region.

For tonight, expectations are for showers to exit the NE WI lakeshore
by 00z. As winds veer to the west- northwest, the gusts will take
some time to subside and likely remain in the 20 to 25 kt range
until 02-05z. Then winds will gradually subside overnight to 10-15
kts.

Conditions will remain VFR as skies gradually clear from
northwest to southeast behind the departing cold front. Cloud
bases will remain above 6 kft until the clearing occurs.

After a period of mostly clear skies overnight, fair weather
clouds will pop with daytime heating on Tuesday. Coverage will be
highest north and west of the Fox Valley, but ceilings will likely
be above 4.5 to 6 kft. West-northwest wind gusts to 20 kts can be
expected on Tuesday afternoon.

&&

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

&&

$$

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