NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 250444
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1144 PM CDT Sun May 24 2026

Updated aviation portion for 06Z TAF issuance

.UPDATE...
Issued at 934 PM CDT Sun May 24 2026

Dense marine fog will impact Lake Michigan, and a Marine Dense
Fog Advisory is in effect through 10 am Monday. Some of the
fog is working its way inland along the lakeshore, so have issued
a Special Weather Statement to alert for locally hazardous travel
conditions through Monday morning. If the fog becomes more
extensive over the lakeshore counties, a Dense Fog Advisory may
need to be issued later tonight.

Attempted to adjust pops a bit based on ongoing activity and
satellite trends. Weakening cluster of showers moving into NE WI
should continue to fall apart over the next couple hours. Have
backed off on pops over our western counties late tonight, and
focused more on the 12z-18z/Mon period, when a short-wave
(currently over the Dakotas), increased H8 flow and a warm front
will be moving through. The best precip chances look to occur over
the northwest half of the forecast area.

&&

.KEY MESSAGES...

- Dense marine fog will continue on Lake Michigan into Monday
  morning. A Marine Dense Fog Advisory is in effect through 10 am
  Monday. Some of the fog will work its way inland, resulting in
  hazardous travel over portions of Door, Kewaunee and Manitowoc
  counties.

- Intermittent chances for rain (20-40%) and thunderstorms are
  forecast through Wednesday. The risk for organized heavier rain
  or severe weather is low.

- Above normal temperatures are expected through the week, with
  80s forecast for Memorial Day, Tuesday, and Wednesday. A few
  spots may approach or reach 90 on Tuesday and Wednesday.

&&

.DISCUSSION...
Issued at 221 PM CDT Sun May 24 2026

Daytime cu popping up this afternoon, otherwise dry and
seasonable weather with temperatures at 19Z in the upper 60s to
mid 70s away from Lake Michigan (closer to 60 degrees near the
lake). Expect temps to rise a few more degrees throughout the
afternoon.

Precipitation: Clouds clear early this evening, followed by mid
clouds moving in from the west generated by some weak warm
advection. Additionally, 850mb jet increases late tonight which
may provide enough forcing to generate some widely scattered
showers. CAMs remain mixed on this potential, and moisture is also
limited. Continued to carry mainly slight chance PoPs (15-25%)
from late tonight into Monday. There are also small isolated
thunder chances (~15%) with 500-1000 J/kg of MUCAPE, but severe
storms are not expected.

Continue to see small precipitation potential both Tuesday and
Wednesday, mainly during the afternoon and early evenings, from
weak features and daytime heated. Isolated, non-severe
thunderstorms are also possible (~15-20% probability) with some
instability present.

Surface high pressure dominates the area from Thursday through
next weekend which will result in little to no precipitation.

Temperatures...Readings will trend above normal for the next week,
peaking on Tuesday with highs the 80s to possibly low 90s. NBM
shows a 50-70% probability for parts of central into northeast WI
reaching or exceeding 90 degrees. While dew points will be
tolerable in the 50s to low 60s, there is a moderate (level 2 of
4) heat risk, meaning prolonged periods outside could affect those
who are sensitive to heat.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1135 PM CDT Sun May 24 2026

Showers that moved through northern WI this evening dissipated as
they moved through far NE WI, leaving dry conditions across the
forecast area. Widespread dense marine fog was evident over Lake
Michigan per satellite and web cams, but has not pushed inland
enough to impact the MTW TAF site.

Still expect the marine fog to move farther inland overnight,
eventually bringing LIFR flight conditions to MTW before
dissipating Monday morning. Other than the marine fog along the
lakeshore, VFR conditions are anticipated for the rest of the
forecast area.

Precipitation trends are a bit tough to discern. Have backed off
on additional precipitation development overnight, but a short-
wave moving through the eastern Dakotas should bring at least
scattered showers and isolated storms to at least the western TAF
sites Monday morning.

Light SE-S winds tonight will become quite gusty from the
southwest after a warm front moves through on Monday. It appears
that some LLWS will develop over the region later Monday evening.

&&

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

&&

$$

UPDATE.........Kieckbusch
DISCUSSION.....KLJ
AVIATION.......Kieckbusch