NWS-Green Bay Forecast Discussion
FXUS63 KGRB 191043
AFDGRB
Area Forecast Discussion
National Weather Service Green Bay WI
543 AM CDT Thu Mar 19 2026
Updated aviation portion for 12Z TAF issuance
.UPDATE...
Issued at 426 AM CDT Thu Mar 19 2026
The wintry mix has ended across the region early this morning. In
its wake, low level moisture over the cold snowpack has led to
some patchy fog across portions of central and north-central
Wisconsin early this morning. The fog may be locally dense at
times and may impact the morning commute. The fog is expected to
lift a few hours after sunrise.
&&
.KEY MESSAGES...
- Patchy fog, locally dense at times, will affect portions of
central and north-central Wisconsin this morning.
- Temperatures continue rising above normal, with the warmth
peaking Saturday. Snowmelt and increased flows and rising levels
on rivers and streams are expected. Several rivers may reach
bankfull or even minor flood stage.
&&
.DISCUSSION...
Issued at 131 AM CDT Thu Mar 19 2026
The wintry mix associated with a clipper system will end across
the region early this morning. There could be some minor impacts
with the morning commute, especially on untreated roadways.
Otherwise, dry weather is expected once this system tracks east
for the rest of the morning and into the afternoon. Temperatures
continue their climb today, as highs reach into the 40s away from
the lakeshore.
Another clipper system will affect the area tonight, mainly
bringing light rain to the northern and eastern CWA as
temperatures stay in the 30s. The warming trend continues across
the region on Friday as highs reach the 40s across the Fox Valley
and lakeshore, with around 50 across central and north-central
Wisconsin. The warming will bring an increased risk for fog with
the warm air advecting over the substantial snowpack, especially
during the overnight hours.
A low pressure system developing over the Plains will bring a
surge of warm air to the region on Saturday along with some small
chances for rain across far north-central Wisconsin. This will
likely be the warmest day in the upcoming week as temperatures
soar into the 50s across central Wisconsin with a 20-40% chance of
hitting 60 degrees south of Highway 10.
The cold side of this low pressure system will track through
the area Saturday night, bringing colder temperatures and a
rain/snow mix as a cold front sinks south through Sunday. There
is still quite a bit of uncertainty with respect to impacts with
this system as some models are more robust with QPF amounts, which
is evident with the large spread between the 50th and 90th
percentiles for snowfall amounts.
High pressure will then provide dry weather to the area early next
week. Despite the passage of the aforementioned cold front, highs
will still remain in the 30s and 40s through early next week.
These "cooler" temperatures appear to be short lived as warmer
temperatures in the 40s and 50s are expected to return by the
middle of next week, which will continue the snowmelt along with
the threat for fog. Additional clipper systems are expected to
impact the region during the middle part of next week, bringing
the chance for precipitation at times. Although the first one of
these systems appears to have minimal impact with light
precipitation, the second one could be more interesting depending
on how much moisture can advect northward.
&&
.AVIATION...for 12Z TAF Issuance
Issued at 531 AM CDT Thu Mar 19 2026
Precipitation has come to an end at the TAF sites. Some patchy
fog/stratus will lower conditions to IFR/LIFR at times through
13/14Z until it mixes out, especially across central and north-
central Wisconsin TAF sites. Once any fog mixes out, VFR
conditions are then expected the rest of today.
A clipper system will track to the north tonight, which could
bring some light precipitation to far northern Wisconsin. The TAF
sites are expected to remain dry tonight. There is a better chance
(60-80%) for MVFR CIGs and some patchy fog tonight across central
and north-central Wisconsin as low level moisture gets trapped
under an inversion.
&&
.HYDROLOGY...
Issued at 131 AM CDT Thu Mar 19 2026
As temperatures warm later this week into the weekend, the
snowmelt will result in increasing fast flows and rising river
levels. Some rivers could reach bankfull or even minor flood
stage. The lack of a rapid, significant warmup points to a more
gradual rise in area rivers as opposed to widespread rapid rise
flooding. That being said, the flooding situation will be
monitored closely given how much water is locked up in the current
snowpack across the region.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE.........Kurimski
DISCUSSION.....Kurimski
AVIATION.......Kurimski
HYDROLOGY......Kurimski