Drought in Wisconsin, December 1 to 31, 2023

Area Forecast Discussion
National Weather Service Green Bay WI
1045 PM CST Thu Nov 30 2023

Updated aviation portion for 06Z TAF issuance

.KEY MESSAGES...

- Slick spots on area roads from frost and refreezing of melted
  snow will be possible again for the Friday morning commute.

- Light snow accumulations and a wintry mix could lead to some
  slippery roads on late Saturday night into Sunday morning.

- Light wintry precip is also possible on Monday night into
  Tuesday.

.DISCUSSION...
Issued at 214 PM CST Thu Nov 30 2023

SHORT TERM...

Forecast Details:

Sunny skies and winds remaining light out of the north allowed for
temperatures to push well into the middle to upper 40s across the
region today

The only concern for the short term forecast arrives in the area
again tonight. Weak surface high pressure will keep skies clear
for most of the area, making for a relatively cold night with low
temperatures in the lower teens to lower 20s. As temperatures
approach the dewpoint in the hours leading up to sunrise, fog and
frost seem likely, which may lead to frost deposition on area
roads once again. This could produce some slippery spots across
the area for the morning commute before warming temperatures in
the late morning reduce slick spots once again.

Friday, a system to our south will bring overrunning cloud cover
to the region through the morning hours and early afternoon. Winds
will change over to the northeast during this period, which in
conjunction with the cloud cover will keep temperatures cooler
than today. Highs are forecast to be in the 30s for most of the
region. Although precipitation directly associated with the
southerly system will largely miss the area until Friday night,
some meso models do support some small lake effect showers as the
northeast flow comes into the Bay of Green Bay and Door County.
Added some light pops to the area to account for this Friday
afternoon, but expect impacts to be minimal as the most likely
precipitation type is drizzle.

LONG TERM...

There is potential for wintry weather during two periods in this
part of the forecast, namely Saturday night into Sunday and also
Monday night into Tuesday.  While neither system appears to a
prolific winter weather producer, minor travel impacts seem possible
with both systems.

Saturday night through Sunday...Disjointed shortwave energy will be
passing across the region during this time period, resulting in weak
shortwave energy moving across the southwest to central Great Lakes.
The strongest QG forcing will likely pass south of the region, while
farther north, weak mid-level convergence and isentropic ascent
remains on track to lead to sufficient saturation for light precip
across at least parts of the area.

Probabilities suggest central, east-central, and far northeast WI
will have the highest chances (30-50%).  Ptype probabilities suggest
areas north and west of the Fox Valley will see mostly snow, while
the Fox Valley and Lakeshore areas will see a wintry mix.  However,
considering precip will be moving in during the diurnal minimum of
temps and operational models are sufficiently cold, think
probabilities for snow are higher than the NBM suggests over the Fox
Valley.

In general, probabilities of 1" or greater of snow accumulations
remains low and under 30%.  But with forecast qpf amounts from 0.1"
to 0.2" over east-central WI, it's possible probabilities are higher
than the current forecast indicates.  However, the probabilities of
greater than 2" of snow has been steadily decreasing in the past
several model cycles, and therefore will remain conservative with
QPF and snow amounts.

Monday night through Tuesday...Dynamics are more robust with a
clipper system forecast to move across the region in this time
period.  Model spread is rather high with this system, which leads
to a lower confidence forecast.  Central to east-central Wisconsin
stands to have the highest chances for wintry weather over this
period with the GEFS/EPS suggesting upwards of 0.10" of precip. But
given the potential for stronger dynamics, will monitor over the
coming days.

Temperatures...Will be holding relatively steady for the next week
and near to slightly warmer than normal.
&&

.AVIATION...for 06Z TAF Issuance
Issued at 1044 PM CST Thu Nov 30 2023

VFR conditions will prevail late this evening with a few
scattered clouds around 4000-5000 ft, especially across northern
Vilas County and near Lake Michigan. Ground fog will possible
again overnight. Despite the lighter winds, HREF and SREF showing
lower percentages tonight compared to last night, likely to due to
slightly drier air in the lower levels. But will keep some lower
VSBYs in central and north central WI where models have the
highest chance (30-50%) of seeing a period of fog. Otherwise, VFR
conditions are expected. Any fog will lift by mid-morning on
Friday, with mid and high clouds spreading into the area from the
south/west. MVFR ceilings are expected to arrive across the Fox
Valley and lakeshore in the afternoon and evening as a system
approaching from the southwest. A light mix of rain and snow could
also clip MTW Friday evening.
&&

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

DISCUSSION.....Uhlmann/MPC
AVIATION.......Bersch

Hazardous Weather Outlook
National Weather Service Green Bay WI
137 PM CST Thu Nov 30 2023

WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074-011945-
Vilas-Oneida-Forest-Florence-Northern Marinette County-Lincoln-
Langlade-Menominee-Northern Oconto County-Door-Marathon-Shawano-
Wood-Portage-Waupaca-Outagamie-Brown-Kewaunee-Waushara-Winnebago-
Calumet-Manitowoc-Southern Marinette County-
Southern Oconto County-
137 PM CST Thu Nov 30 2023

This Hazardous Weather Outlook is for north-central and northeast
Wisconsin.

.DAY ONE...Tonight

Slick spots on area roads from frost and refreezing of melted
snow will be possible again for the Friday morning commute.

.DAYS TWO THROUGH SEVEN...Friday through Thursday

Light snow accumulations and a wintry mix could lead to some
slippery roads on late Saturday night into Sunday morning.

Light wintry precip is also possible on Monday night into
Tuesday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed tonight.

LMZ521-522-541>543-011945-
The Bay of Green Bay south of a line from Cedar River MI to Rock
Island Passage-Lake Michigan from Washington Island to Sheboygan-
137 PM CST Thu Nov 30 2023

This Hazardous Weather Outlook is for portions of northwest Lake
Michigan and the waters of Green Bay.

.DAY ONE...Tonight

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Friday through Thursday

The probability for widespread hazardous weather is low.

Uhlmann/MPC