Forecast Discussion for GRB NWS Office
FXUS63 KGRB 270925

Area Forecast Discussion
National Weather Service Green Bay WI
325 AM CST Thu Jan 27 2022

Forecast discussion for routine morning forecast issuance

.SHORT TERM...Today...Tonight...and Friday
Issued at 325 AM CST Thu Jan 27 2022

Scattered snow showers will precede a cold front
that will move across the area in the afternoon. Little moisture
is available so do not expect more than a dusting in most places.
Highs today will be in the 20s before the front goes by, making
this the warmest day in about a week or so.

Skies should clear tonight as a surface high builds into the western
Great lakes. Lows will be below zero in most places with wind chills
of 15 to 20 below in central and northcentral Wisconsin.

Friday will be partly sunny and cold, with highs around ten
degrees cooler than average.

.LONG TERM...Friday Night Through Wednesday
Issued at 325 AM CST Thu Jan 27 2022

The main highlights from this forecast period revolve around the
small chance for light snow Saturday evening, followed by a gradual
rise in temperatures into early next week, and the potential for
more significant precipitation midweek.

Friday night through Sunday...High pressure will reside over the
forecast area Friday night, keeping mostly clear skies in the
forecast. Temperatures overnight will still be on the cold side, but
not as cold as the previous nights as the core of the cold airmass
will be exiting. This will put lows in the single digits below zero
for Friday night. For Saturday, models are still indicating a
clipper system will track across southwestern Ontario and Lake
Superior. Due to the model consistency with this clipper, felt
confident enough to add in small chances for snow during the
afternoon and evening, with the highest chances in far northeast WI.
Also, added some lingering chances for lake-effect snow in far north-
central WI into Saturday night due to the trailing low-level
northwest flow. Anticipating snowfall amounts of up to 1 inch, with
the highest amounts along the Door Peninsula. High pressure will
move in for Sunday following the clipper, with temperatures closer
to normal with readings in the 20s.

Rest of the extended...As upper-level ridging builds over the Upper
Mississippi Valley on Monday, low-level southwest flow will lift
warmer air into the region. High temperatures will be above normal
with readings in the upper 20s and low 30s. A clipper system then
looks to track east across the Upper Mississippi Valley Monday night
into Tuesday. Models are not in exact agreement with this clipper
bringing precipitation to the forecast area as there appears to be a
limited amount of moisture in addition to timing differences.
However, the bigger question is how this clipper`s trailing cold
front will interact with the continued low-level southwest flow on
Tuesday. Some models indicate no precipitation for Tuesday due to
the cold front moving through faster, while others have some
precipitation lifting into southeastern WI in association with the
southwest flow ahead of the cold frontal passage. Despite the large
spreads in the models and little run to run consistency, there are
signs of this southwest flow combining with a strong feed of Gulf
moisture Wednesday and Thursday. This could bring a significant
amount of precipitation to the area midweek, but there are plenty of
unknowns at this time that could change the forecast drastically for
the area.

.AVIATION...for 06Z TAF Issuance
Issued at 1033 PM CST Wed Jan 26 2022

The gusty surface winds and LLWS will gradually abate overnight
into Thursday morning. A band of clouds with lower (MVFR)
ceilings will overspread the area overnight and linger into
Thursday. There is a chance of light snow or flurries, though
the flight category will primarily be driven by the cloud bases.



LONG TERM......Hykin

NWS GRB Office Area Forecast Discussion