034 
FXUS63 KBIS 242104
AFDBIS

AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
304 PM CST Sat Dec 24 2022

.SHORT TERM...(This Evening through Sunday) 
Issued at 304 PM CST Sat Dec 24 2022

Light snowfall accumulations, strong winds, and the start of a 
warming trend highlight the short term forecast period. 

Western and central North Dakota is currently situated under 
northwest flow aloft and surface high pressure. Clouds across the 
west should continue to erode through the afternoon before 
increasing again tonight. We have one more bitterly cold night on
tap, with actual lows ranging from the upper teens/lower 20s 
below zero east to the single digits below west. This will mean 
overnight wind chills in the 40 to 25 below zero range for all 
except for portions of the west. The Wind Chill Advisory remains 
in effect for all of these areas through Christmas Sunday morning.

Precipitation chances increase overnight through Sunday, from 
northwest to southeast as an Alberta Clipper moves across the state. 
Strong upper level forcing will overspread strong low to mid level 
frontogensis and steep mid level lapse rates. All parameters appear 
to be in place for a mesoscale band of moderate to heavy snow to 
develop along the best frontogenetical signal, wherever that sets 
up. NBM consensus suggests the heaviest part of this band will 
setup from the north central, southeast through the greater 
Devil's Lake Basin, and into the James River Valley. While 
residence time should be relatively short under any one specific 
location (quick moving system), areas under the heaviest parts of 
the band could end up seeing 2 to 4 inches of accumulation with 
some locally higher amounts possible. Depending on how things 
evolve, instability from the lapse rates and very strong cold air 
advection could lead to some snow squall activity and it will be 
something we have to closely monitor. 

All that said, we decided to go ahead and issue a Winter Weather 
Advisory for snowfall accumulations of 2 to 4 inches and areas of 
blowing snow for Renville, Ward, Bottineau, McHenry, Sheridan, 
Kidder, Dickey, LaMoure, Rolette, Pierce, Wells, Foster, and 
Stutsman counties. This is the area we are most confident will 
see the greatest impacts and the advisory will be in effect from 
06z Sunday through 06z Monday. West of the advisory, impactful 
winter weather is a bit more uncertain with lower snow totals and 
warmer temperatures. Soundings suggest much of the west and 
central could see a brief period of a wintry mix which could lead 
to a light glaze of ice accumulation. Very strong winds are also 
looking likely behind a cold front that will cross the state, 
especially across the southwest and south central with all 
guidance suggesting strong cold air advection, steep lapse rates, 
and strong pressure rises. Soundings suggest there could be 55 
knots or greater of wind available to mix down at the top of the 
mixed layer for some locations. EFI values also confirm the 
potential for very strong winds here and were are advertising
gusts up to 55 mph. Blowing snow could become a real problem 
southwest and south central, but temperatures could be the fly in 
the ointment. We will see significant warm air advection during 
the first part of the day across the southwest which will lead to 
highs in the lower 30s to upper 30s southwest and south central. 
This will make any snow on the ground much harder to loft. We will
end up needing some sort of headline for this potential in the 
next shift or two, but uncertainty remains where that dividing 
line (if any) between just "wind" impacts and "winter" impacts 
will setup, complicating the forecast. For now, confidence is just
not there to make that delineation. 

.LONG TERM...(Sunday Night through Saturday)
Issued at 304 PM CST Sat Dec 24 2022

Some light snow may linger Sunday night but surface high pressure 
should settle in and push it out overnight and into Monday morning. 
On the backside of the Clipper, we could see another night on the 
colder side and one more night of a Wind Chill Advisory is possible 
across the east. While apparent temperatures will not be as bad as 
they have been recently, it still looks like widespread readings of 
30 to 25 below are likely. 

Monday looks to be dry as upper ridging starts to push in. During 
the afternoon highs will rise into the mid 20s to mid 30s west and 
into the single digits to upper teens central and east. For the rest 
of the period, expect highs generally in the 20s and 30s with a 
chance for some lower 40s across the southwest. Another couple of 
weak waves will move through the region, bringing light precipitation
chances back into the forecast Tuesday and Thursday. But given 
the low predictability of the pattern and model/ensemble 
disagreement, specifics are murky at this time. 

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1141 AM CST Sat Dec 24 2022

The first part of the period will see VFR conditions across the
state, but the next Clipper will bring increasing chances of
precipitation and lower ceilings from northwest to southeast
tonight through Sunday. Precipitation will be snow for most
but there is a potential for some light rain or freezing rain
across the west towards the end of the period. Too much
uncertainty still remains on location and potential for mention in
site specific forecasts at this time. Ceilings will generally
bottom out in MVFR categories, but brief IFR conditions are
possible under any heavier snow pockets or in areas of blowing
snow. There will also be enhanced low level wind shear overnight
through Sunday morning.  

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Wind Chill Advisory until 6 AM CST /5 AM MST/ Sunday for 
NDZ001>003-009>011-019>021-034-042-045.

Winter Weather Advisory from midnight tonight to midnight CST 
Sunday night for NDZ003>005-011>013-022-023-025-036-037-048-051.

Wind Chill Advisory until 9 AM CST Sunday for NDZ004-005-012-013-
022-023-025-035>037-046>048-050-051.

&&

$$

SHORT TERM...ZH
LONG TERM...ZH
AVIATION...ZH