NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 030429
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1029 PM CST Mon Mar 2 2026

Updated aviation portion for 06Z TAF issuance

.KEY MESSAGES...

- A more spring-like pattern sets up this week with chances for
  very light mixed precip tonight into Tuesday (10-20%), then
  mainly rain mid-week (20-55%) and again late in the week (60-
  80%). Chance for storms arrives on Friday, mainly south.

- A gradual warming trend begins today and continues through the
  week. Ice jam/floe, minor flooding, and fog concerns may arise.

&&

.DISCUSSION...
Issued at 302 PM CST Mon Mar 2 2026

Dry weather expected through most of the night, with a small
(15-20%) chance of light, mixed precip late tonight into Tuesday
morning due to low level warm advection and some weak fgen.
Latest forecast soundings look less supportive of generating any
precip than previous runs, with better moisture and forcing
located farther south. However, there is a brief window from about
12-16Z with some saturation up to about 8-10kft and weak lift. Ice
crystal formation looks minimal, meaning a rain/freezing rain
setup. Surface temps will be around 32F near sunrise, but will
quickly rise afterwards. Therefore, impacts from any freezing rain
will be limited as roads warm up. Continued small PoPs south of
Hwy 29 where there is a 20% chance for 0.01" of precip. Cannot
rule out some very light precip farther north, but chances are
even lower.

Expect some clearing late in the day Tuesday, and the warming
trend to continue with highs in the lower 40s. Temperatures to
remain above normal through the weekend with highs in the 40s and
50s.

Upper level split flow and weak mid-level shortwave bring low to
medium rain chances (20-50%) Wednesday night into Thursday. Ptypes
of rain would be expected, with ~10-50% chance for 0.10" of rain,
highest in the southern forecast area/east-central Wisconsin.

The main system of concern to impact the area Friday into
Saturday morning as a dynamic low pressure system moves from the
central Plains to the western Great Lakes. Rain is the main
concern, with thunder also possible. Max forecast pwats are
around 1.30", near climatological maximum, with NBM probs of
getting 1.0" of rain or more around 20-50% across the southeast
half of the forecast area. Therefore, heavier areas of
precipitation are possible which could bring minor flooding
impacts. This system is still four days away, so plenty of time to
monitor trends and see any shifts in the track. CAPE values of
around 200-400 J/kg also spread into the area Friday night, so
some thunder is possible, with severe weather potential much
farther south.

Fog...Fog potential increases through the week as rising dew
points and melting snow add low- level moisture. The greatest
potential for fog development is across central and northern WI
where the greatest snowpack remains, and when winds will be light
with mostly clear skies.

Minor Flooding and Ice Jam/Floe Potential...The threat for
flooding this week will be very low as temps will be above
freezing during the day and below freezing at night, allowing for
a slow melt which will chip away at the remaining snowpack. The
flooding threat increases late Friday into Saturday, if/where a
heavier area of rain were to occur, as 10-20" frost depths will
limit how much rain will be able to soak into the ground. 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. However, the
ice jam threat will be reduced a little due to the rivers running
pretty low.

Ice Floe Potential...Depending on how strong the system on
Friday/Saturday is, a threat for ice floes may develop, especially
with additional melting/thinning of the ice through the week.

&&

.AVIATION...for 06Z TAF Issuance
Issued at 1029 PM CST Mon Mar 2 2026

Cigs MVFR to VFR rest of tonight, with lowest cigs central to
north-central WI.

Uncertainty still remains on whether any light mixed precip will
enter the area late tonight. Latest trends seem to indicate area
of light precipitation over southern MN may diminish and/or stay
south of all the TAF sites. For now, will keep any precip mention
out of TAFs. Otherwise, MVFR to VFR clouds will gradually scatter
out on Tuesday afternoon. Winds will be light through the TAF period.

&&

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

&&

$$

DISCUSSION.....KLJ
AVIATION.......JLA