Forecast Discussion for GRB NWS Office
178
FXUS63 KGRB 030522
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
1222 AM CDT Sun May 3 2026
Forecast discussion for routine afternoon forecast issuance
.KEY MESSAGES...
- Scattered rain showers today and Monday (20-50%). Best chance of
thunder is Monday afternoon east-central WI. No severe weather
expected.
- Breezy today and Monday. A 40-80% chance of wind gusts over 35
mph on Monday, strongest eastern WI.
- Warmer through Monday, then temperatures fall back below
average rest of the week. Risk for Frost/Freeze Headlines starts
up again Tuesday night.
&&
.DISCUSSION...
Issued at 1221 AM CDT Sun May 3 2026
Two cold fronts shift across the area today and Monday. Ambient dry
air and limited large scale forcing will cut into shower chances
through this morning, but building MUCAPE up to 400J/kg this
afternoon will support renewal of showers and a few thunderstorms
over far northeast WI and across Door County where there is good
signal in CAMs for additional development closer to sfc low and
cold front. Second cold front crosses on Monday afternoon. Ahead
of the front it will be warm and breezy with highs over 70 for
all but north-central WI and wind gusts over 35 mph, especially
eastern WI. Despite the front pushing into the warmer regime,
marginally steep mid-level lapse rates and overall dry airmass
lead to instability that is not all that robust (MLCAPES up to
500J/kg). Even so, still like chances for some thunder given the
front arrives during peak heating over eastern WI. Also boosted
pops over NBM in those areas based on LREF probabilities of
measurable QPF. No severe weather or heavy rain expected, but
given the strong winds aloft and steeper low-level lapse rates,
could see a stronger storm producing isolated wind gusts 40-50
mph.
Second frontal passage briefly puts an end to the warmer and unsettled
pattern, though a few showers could pop-up in the cooler air
aloft on Tuesday. Otherwise, rest of the week looks like last week
with a cooler setup and small chances for showers. A better
signal is emerging for showers even this far out on Thursday as
pretty vigorous shortwave is progged to drop across in the mean
troughing aloft. Temps well below zero at 850mb during that time
would favor snowflakes mixing in at times. Seems that after a
brief hiatus, Frost/Freeze potential will return beginning Tuesday
night and this likely will last through at least Thursday night,
if not Friday night.
Temperatures bounce back to at or above normal next weekend as
warmer ridge over the western CONUS begins to make shift toward
plains/midwest.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1021 PM CDT Sat May 2 2026
Shortwave energy over northern Minnesota will push a weak cold
front across the region on Sunday. Mid-clouds continue to increase
late this evening, but shower chances look mainly confined to
06z-14z Sunday. Probabilities are highest at KRHI (40-50%) and
20-30% elsewhere. Upgraded KRHI to a tempo group, but kept the
prob30s at the other terminals. Flight conditions should remain
VFR in the showers since cloud bases will be quite high.
After the showers depart, clearing skies and breezy conditions can
be expected from late morning Sun through the end of the taf
period. Southwest winds overnight will veer to the northwest and
gust to 20 kts on Sunday afternoon.
Lastly, low level wind shear remains in the forecast during the
06z-14z time frame.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....JLA
AVIATION.......MPC
NWS GRB Office Area Forecast Discussion