NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 051118
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
618 AM CDT Tue May 5 2026

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- Cooler temperatures are expected for the rest of the week, with
  overnight lows approaching freezing. There is a 30-80% chance
  for frost from central to east-central WI Tuesday and Wednesday
  nights (highest in central WI, lowest near the lakeshore).

- Minor precip chances this week with little to no impacts.

&&

.DISCUSSION...
Issued at 236 AM CDT Tue May 5 2026

Surface cold front is southeast of the state now which will allow
winds to subside overnight, and marks the start of a cooler
pattern. The main impacts over the next few days will be
frost/freeze potential during the nights. There are minor precip
chances, but amounts and impacts will be minimal.

Temperatures:
Highs today will be about 15 to 20 cooler than Monday, in the
upper 40s to middle 50s. Similar readings persist on Wednesday and
Thursday, and then return closer to seasonal normals on Friday
and this weekend, in the upper 50s and 60s.

Overnight lows will be the numbers to watch, as temperatures
approach freezing Tuesday night through Thursday night. This will
likely warrant frost or freeze headlines for central and east-
central WI (these products have not yet begun for northern WI). NBM
probabilities show a 30-100% chance of reaching 36 degrees or
cooler Tuesday and Wednesday nights, with the lowest probabilities
in east-central WI near the lakeshore. Frost potential is less
certain Thursday night, with probabilities of 5-60% in central
and east-central WI. By the weekend, overnight lows look to stay
warm enough to avoid frost where the growing season has started.

Precip:
A few precipitation opportunities throughout the week, but impacts
from any precipitation will be minimal. Upper low will spin
northward across Ontario and Hudson Bay the next couple days,
which will keep northeast Wisconsin in northwest flow and send a
few shortwaves through the area. Today's shortwave is likely to be
dry, with only the HRRR showing a few spits of precip. NBM
probabilities for 0.01" of rain are around 5%. Similar situation
on Wednesday, with a 10-20% probability of measurable precip
across northern WI. The potential is best on Thursday (20-40%) for
some measurable rain, again not amounting to much more than a few
hundredths.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 617 AM CDT Tue May 5 2026

VFR conditions are expected through the TAF period. Band of mid-
level clouds will continue to shift southeast across east-central
WI early this morning, with other mid and high clouds expected
today into tonight. Lower clouds, mainly between 3000-8000 ft,
will move across locations near the MI border and Door County
early in the day, with additional daytime cu developing through
the day, with the greatest coverage north and west of the Fox
Valley. Some of these clouds will linger into tonight.

Winds died off during the overnight hours, but west winds will
pick back up through mid-morning, with gusts to around 20 kts
late this morning and afternoon, before subsiding this evening.

&&

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

&&

$$

DISCUSSION.....KLJ
AVIATION.......Bersch