NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 012337
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
537 PM CST Sun Mar 1 2026

Updated aviation portion for 00Z TAF issuance

.KEY MESSAGES...

- A more spring-like pattern sets up this week with chances for
  mixed precip Monday night into Tuesday (20-40%), then mainly
  rain mid-week (25-45%) and again late in the week (60-75%).

- Below normal temperatures continue tonight, then a gradual
  warming trend begins Monday, continuing through the week. Ice
  jam/floe and minor flooding concerns may arise.

&&

.DISCUSSION...
Issued at 249 PM CST Sun Mar 1 2026

Precipitation Chances...Following a dry Monday due to high pressure
overhead, the pattern will transition to a zonal flow and bring
periodic chances for precipitation through the remainder of the
week. The first chance arrives late Monday into Tuesday, from weak
mid-level f-gen and WAA. Models continue indicate this system is
weakening with several deterministic and ensembles showing a dry
forecast or nearly dry. As a result, NBM probs for 0.01" of QPF have
lowered to 25-40% for locations south of Highway 29. Thermal
profiles indicate values hovering around freezing from 3500 ft to
the surface, leading to a light wintry mix. Will continue to monitor
how this evolves as this piece of energy will be better sampled with
the 00z West Coast balloon launches.

Next chance for precip arrives sometime between Wednesday and
Thursday as a low pressure system tracks from the Middle Mississippi
Valley to the Great Lakes. While models are coming into better
agreement with this system's broader details, timing and placement
remain in disagreement. If this system continues on its current
path, the eastern portions of the forecast area will see the
greatest potential for precipitation, in the form of rain.

A greater signal for widespread precipitation looks to arrive late
in the week from a low pressure system ejecting from the central
Plains to the Upper Midwest. With a mean southwesterly flow setting
up, this system will be fueled with Gulf moisture. Depending on the
track of the system and how far north the warm, moist air advects,
there could be some thunderstorm potential for portions of the area.

Temperatures...Another chilly night is expected with lows ranging
from the single digits in the far north to the teens in east-central
WI. Temperatures will gradually rise throughout the week as modified
Pacific air spreads into the Great Lakes. High temperatures will
mainly rise into the 40s, and into the 50s for some spots. Friday is
looking to be the warmest day of the week, with the potential for
some spots to reach 60 degrees (NBM probs of 59+ degrees of 40-60%
in east-central WI).

Fog Potential...Chances for fog will increase throughout the week as
dewpoints increase and snow melt adds to the low-level moisture. The
greatest potential for fog development will be across central and
northern WI where a snowpack remains, and when winds will be light
with clear skies.

Minor Flooding and Ice Jam/Floe Potential...Generally, the threat
for flooding is very low as temperatures will be above freezing
during the day and below freezing at night, slowly chipping away at
the remaining snowpack. The ice jam threat will increase through the
week as many rivers are still fully or partially ice covered and the
warmer temps and increasing flows will promote additional break up.
Gusty south/southwest winds on Monday will increase the threat for
ice floes on Green Bay as well.

&&

.AVIATION...for 00Z TAF Issuance
Issued at 536 PM CST Sun Mar 1 2026

Good flying conditions are expected through Monday. Scattered mid
clouds cross tonight into Monday morning, but overall wall-to-wall
VFR prevails.

Light and variable winds tonight will become southerly and
increase on Monday morning, with gusts 15-20 kts into Monday
afternoon. LLWS is anticipated late tonight through mid-morning
Monday across far northern WI (RHI), as winds around 1500-2000 ft
increase from the SW at 35-40 kts.

The next chance of precipitation, which could be a mix of rain and
snow, arrives late Monday night into Tuesday morning. Greatest
chances for precipitation will be from central to east-central
WI. This will be the next chance for MVFR conditions over the
area.

&&

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

&&

$$

DISCUSSION.....Kruk
AVIATION.......JLA