NWS-Green Bay Forecast Discussion

						FXUS63 KGRB 161130
AFDGRB

Area Forecast Discussion
National Weather Service Green Bay WI
630 AM CDT Mon Mar 16 2026

Updated aviation portion for 12Z TAF issuance

.KEY MESSAGES...

- The historic winter storm will continue to make travel
  extremely difficult to impossible through this morning. Those
  with travel plans, including air travel, should make alternative
  plans.

- Heavy snow and strong northeast winds will result in blizzard
  conditions re-developing this morning, continuing into this
  afternoon. A Blizzard Warning remains in effect until 4 PM.

- An additional 4 to 10 inches of snow is expected through this
  afternoon, highest in/around the Fox Valley.

- Below zero wind chills will be possible today, with
  temperatures moderating back to near normal throughout the week.

&&

.DISCUSSION...
Issued at 1153 PM CDT Sun Mar 15 2026

Historic winter storm continues... Following a brief lull in the
snow late this evening (including periods of freezing drizzle),
we get right back into the brunt of the action as heavy snow has
already begun re-developing from the south in conjunction with a
mid-level shortwave that has deepened into a closed low over
southern Wisconsin. As such, conditions will continue to
deteriorate rapidly over the next several hours as 1"/hr snowfall
rates enter the Fox Valley and lakeshore areas. Provided a deep
DGZ (~12k ft) and ample synoptic support, snow should be able to
accumulate rather quickly throughout the morning. However, have
stuck with lower SLRs since strong winds will likely fracture any
larger dendrites. When combined with said northeast winds gusting
to 45 mph, there is a high likelihood that blizzard conditions
will set in once again, lasting through the morning. When all is
said and done, there remains a high probability (50 to 80% chance)
that the Fox Valley eastward will pick up another 10 inches of
snow through this afternoon, locally higher. Conditions should
then gradually improve by this evening as winds subside and snow
winds down. All in all, we remain on track to go down in the
record books with a widespread 1 to 2 ft of snow, locally up to
30 inches over portions of far northeast Wisconsin.

Headline considerations... No changes made to the headlines on
this shift, with the Blizzard Warning set to go until 4 PM. Main
consideration moving forward will be whether or not to cancel the
Blizzard Warning early, as some CAMs indicate winds dying down
slightly earlier across the northwest portion of the forecast
area.

Bitter cold today... Combination of robust northerly flow and 850
mb temps reading -20 to -22C will result in a quick shot of
arctic air today, with wind chill readings to -10F across the
north, and struggling to hit 0 degrees in/around the Fox Valley.
The cold will not be long-lived as synoptic flow de-amplifies,
resulting in weak ridging moderating temperatures back to near
normal, and even above normal, by the end of the work week. Highs
in the mid to upper 40s will return Thursday into Friday.

Extended... We're not quite done with snow yet, as a couple of
transient clipper lows look to bring additional chances for light
snow through the end of the work week. The first of these
systems, Tuesday into Wednesday, currently looks to take a dive to
our south for the most part, though this is wont to change in the
next day or two. The second, Friday into Saturday, looks to be
more of a classic setup, tracking the surface low over Lake
Superior and affecting mainly the northern snow belts.

&&

.AVIATION...for 12Z TAF Issuance
Issued at 550 AM CDT Mon Mar 16 2026

IFR/LIFR cigs should give way to MVFR conditions later this
morning, though moderate to heavy snowfall will be ongoing at all
terminals. When combined with northeast winds gusting between 30
and 40 knots, blizzard conditions are set to re-develop from south
to north, lasting into this afternoon. As such, quarter mile
vsbys will be possible at all sites. Improvements to VFR are then
possible this evening into tonight as snow and wind gradually
subside. Expect impacts to air travel through at least late this
morning, possibly into the afternoon.

LLWS concerns persist through the first few hours of the TAF
period as a 60 knot low-level jet exits the area. Surface winds
then decrease late this afternoon and evening.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
Blizzard Warning until 4 PM CDT this afternoon for WIZ005-
010>013-018>022-030-031-035>040-045-048>050-073-074.
&&

$$

DISCUSSION.....Goodin
AVIATION.......Goodin