985
FXUS63 KGRB 091748
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
1148 AM CST Mon Feb 9 2026

Updated aviation portion for 18Z TAF issuance
and new information added to update section

.UPDATE...
Issued at 1131 AM CST Mon Feb 9 2026

Have delayed the start time for the Winter Weather Advisory until
6 pm, as very dry air will slow precipitation development. A
general lack of significant/organized radar returns over MN adds
confidence to this change. A later arrival time will result in a
smaller window of opportunity for freezing rain, as the warm
layer aloft will be eroding with time. Will take a closer look at
this in the afternoon, with one viable option being a cancellation
of the headlines.

&&

.KEY MESSAGES...

- There is a 20 to 50 percent chance of a light glazing of ice
  this evening, transitioning to light snow overnight. Slick to
  locally hazardous travel could develop on untreated roads where
  freezing rain occurs.

- Mainly dry conditions with seasonably mild temperatures
  expected for the remainder of the week.

&&

.DISCUSSION...
Issued at 221 AM CST Mon Feb 9 2026

Today-Tonight:

GOES Water vapor imagery shows a well-defined shortwave trough
across the southern Canadian prairies early this morning. This wave
will get sheared out as it progresses east through the day while an
additional shortwave trough moves east from the northern plains this
evening.

Relatively strong mid-level warm advection will take place ahead of
the waves this afternoon/evening while the broader synoptic lift has
perhaps trended a bit weaker across northern Wisconsin. Still expect
the highest chances for light precipitation to be across northern
Wisconsin late today into tonight, with the strong warm nose aloft
favoring freezing rain initially before transitioning to snow
overnight as cooling/wet bulbing occurs through the thermal
profile. Overall, amounts continue to look quite light with a
glazing of ice (40-70% chance over far northern WI, along and
north of Highway 8) and snow under an inch. One notable trend is
for slower onset with soundings from 09.00Z CAMs showing a
deeper layer of dry air centered around 850 mb through the
daytime hours compared with 08.12Z CAMs. As a result, precip
likely will struggle to reach the ground initially.
Consequently, lowered precip chances through the afternoon.

Contemplated delaying the start of the Winter Weather Advisory
a few hours, but with the warm nose aloft and subfreezing wet
bulb temps, any very light precip reaching the ground would
likely fall as freezing rain late this afternoon, so confidence
was not high enough to adjust timing just yet.

Tuesday-Sunday:

Gusty northwest winds will follow behind the clipper system on
Tuesday in the cold advection regime. High pressure will then
settle across the Great Lakes on Wednesday with dry conditions
continuing and seasonable temps. A fairly zonal split flow
pattern will continue through the weekend with a seasonably
mild period in store for late week into the weekend and little
signal for impactful precip at this time over our area. A
southern stream trough is forecast to eject across the lower
Mississippi Valley over the weekend, but chances of precip
locally are low (~20%) for now.

&&

.AVIATION...for 18Z TAF Issuance
Issued at 1131 AM CST Mon Feb 9 2026

/12Z TAFS THROUGH 12Z TUESDAY/...

VFR conditions will prevail through the afternoon and evening,
with mainly mid-level clouds and S-SW winds gusting to 15 to 20
knots expected. Have delayed any mention of precipitation in the
RHI TAF site until 01z/Tue.

The highest precipitation chances will be focused across far
northern Wisconsin (including the RHI TAF site) this evening into
tonight with patchy light freezing rain/sleet transitioning to
snow. If precipitation arrival is delayed any later into the
evening, the potential for freezing rain will be much lower, due
to a weakening of the warm layer aloft. Not planning to add any
precipitation toany of the other TAF sites.

There is potential for MVFR ceilings developing in the wake of a
cold frontal passage late tonight into Tuesday morning,
especially over NC/C WI.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory from 6 PM this evening to 3 AM CST
Tuesday for WIZ005-010>013-021-022-073.
&&

$$

UPDATE.........Kieckbusch
DISCUSSION.....JM
AVIATION.......Kieckbusch

NWS GRB Office Area Forecast Discussion