Heavy Snow in North Dakota, December 4 to 5, 2021

Area Forecast Discussion
National Weather Service Bismarck ND
631 PM CST Sat Dec 4 2021

.UPDATE...
Issued at 631 PM CST Sat Dec 4 2021

Message for ongoing system remains the same with this update.

Band of light to moderate snow continues from northwest into
south central and southeast North Dakota this evening, along a
700mb frontogenesis max. This will continue to push east this
evening as the upstream low enters the area. Water vapor imagery
depicts a deepening shortwave trough entering north central
Montana with implied upper level divergence increasing over
northeast Montana and into northwest North Dakota. Upstream
observations at Glasgow and Wolf Point have experienced 1/4 mile
visibility and heavy snow at times as this upper level divergence
has coupled with the low-mid level baroclinic zone to produce
bands of heavy snowfall rates. These interacting forcing
mechanisms will transition east tonight, likely impacting the
Highway 2 corridor of North Dakota to produce similar conditions.
The overall system is relatively progressive with strongest ascent
lasting no more than a few hours at any one location, but
continues to look adequate for warning criteria snow exceeding 6
inches in many areas of the north tonight.

&&

.SHORT TERM...(This evening through Sunday night)
Issued at 243 PM CST Sat Dec 4 2021

The forecast challenge for the near term remains the ongoing
winter storm. Presently, isentropic ascent ahead of an approaching
shortwave is producing snow in much of south central through
northwestern North Dakota. Snow should continue to increase in
coverage and intensity tonight as the trough passes through the
area. Heaviest snowfalls are expected in the northern half of the
forecast area where 4 to 8 inches of snow, with locally higher
amounts, is possible. Lesser amounts are expected further south
and west.

The associated surface low will pass through the state tonight
through Sunday morning. As surface pressure scoots eastward, a
tight pressure gradient develops over the region on the backside
as the area is sandwiched by the low to the southeast and high
pressure meandering to the southeast from southwestern Canada.
Therefore, very windy conditions will develop, especially across
the southern portion of the forecast area. Expect the pressure
gradient to loosen Sunday night as aforementioned high pressure
nudges into the region. This, along with clearing skies, will
produce some of the coldest temperatures of the year with lows
near zero south to the teens below zero north.

In regards to headlines, upgraded four counties in central North
Dakota to a winter storm warning, expanded the winter weather
advisory into the southern James River Valley, and issued a high
wind warning for Sunday in portions of southwestern and south
central North Dakota.

.LONG TERM...(Monday through Saturday)
Issued at 243 PM CST Sat Dec 4 2021

An arctic high moves over the area Monday resulting in quite cold
temperatures to start the extended period. Highs on Monday for
most locations north and east of the Missouri River will be in
the single digits above zero, while areas to the southwest will
range from 10 to 20 degrees. Similar highs are on tap for the day
Tuesday as well. Monday night and Tuesday night will also be
quite cold as lows will range from the single digits below to the
single digits above zero.

Conditions should moderate by mid-week as warmer air advects into
the region. Still, highs aren't expected to be much above average
for this time of the year, while lows dip back into the single
digits above zero for most locations by the weekend. In regards
to precipitation, could see a little snow Wednesday night into
Thursday as a shortwave energy clips through the area.

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 631 PM CST Sat Dec 4 2021

Strong low pressure is bringing accumulating snow to much of
western and central North Dakota this evening, and will continue
to spread east overnight. MVFR/IFR ceilings and visibilities are
expected at times at all TAF sites. Gusty winds out of the
southeast tonight will shift northwest early Sunday morning as a
front pushes from west to east. Northwest winds will become
strong during the day Sunday, especially south. Though snow will
be tapering off during this time, blowing snow may continue to
cause visibility reductions during the day.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 PM CST /5 PM MST/ Sunday for
NDZ017>020-035>037-047-048-051.

High Wind Warning from 6 AM CST /5 AM MST/ to 6 PM CST /5 PM
MST/ Sunday for NDZ031>034-040>046-050.

Winter Storm Warning until 6 PM CST Sunday for NDZ001>005-
009>013-021>023-025.

&&

UPDATE...AE
SHORT TERM...Telken
LONG TERM...Telken
AVIATION...AE

Hazardous Weather Outlook
National Weather Service Bismarck ND
225 PM CST Sat Dec 4 2021

NDZ001>005-009>013-021>023-025-052030-
Divide-Burke-Renville-Bottineau-Rolette-Williams-Mountrail-Ward-
McHenry-Pierce-McLean-Sheridan-Wells-Foster-
225 PM CST Sat Dec 4 2021

This Hazardous Weather Outlook is for portions of north central
North Dakota, northwest North Dakota, south central North Dakota,
and southeast North Dakota.

.DAY ONE...This Afternoon and Tonight

A Winter Storm Warning is in effect this afternoon through Sunday
afternoon. See weather.gov/bis for details.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

A Winter Storm Warning is in effect through Sunday afternoon. See
weather.gov/bis for details.

Very cold wind chills as low as 30 below zero are forecast Sunday
night through Monday morning, and again Monday night through
Tuesday morning.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report snow amounts to the National
Weather Service via social media or by calling 1-800-247-0212.

NDZ017>020-035>037-047-048-051-052030-
McKenzie-Dunn-Mercer-Oliver-Burleigh-Kidder-Stutsman-Logan-
La Moure-Dickey-
225 PM CST Sat Dec 4 2021 /125 PM MST Sat Dec 4 2021/

This Hazardous Weather Outlook is for portions of northwest North
Dakota, south central North Dakota, southeast North Dakota, and
southwest North Dakota.

.DAY ONE...This Afternoon and Tonight

A Winter Weather Advisory is in effect this afternoon through
Sunday afternoon. See weather.gov/bis for details.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

A Winter Weather Advisory is in effect through Sunday afternoon.
See weather.gov/bis for details.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report snow amounts to the National
Weather Service via social media or by calling 1-800-247-0212.

NDZ031>034-040>046-050-052030-
Golden Valley-Billings-Stark-Morton-Slope-Hettinger-Grant-Bowman-
Adams-Sioux-Emmons-McIntosh-
225 PM CST Sat Dec 4 2021 /125 PM MST Sat Dec 4 2021/

This Hazardous Weather Outlook is for portions of south central
North Dakota, southeast North Dakota, and southwest North Dakota.

.DAY ONE...This Afternoon and Tonight

The probability for widespread hazardous weather is low.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

A High Wind Warning is in effect Sunday morning through Sunday
afternoon. See weather.gov/bis for details.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report snow amounts to the National
Weather Service via social media or by calling 1-800-247-0212.

Telken