386
FXUS63 KBIS 221503
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
903 AM CST Fri Nov 22 2024

.KEY MESSAGES...

- There is a 60 to 90 percent chance of accumulating snow this
  weekend in the north, with chances decreasing towards the
  south. There is a 60 percent chance of at least 2 inches of
  snow along the Canadian Border.

- Below average temperatures are expected through this weekend
  and into next week. Highs will mainly be in the 20s and 30s,
  and lows mainly in the single digits to teens above zero.
  Monday will be colder, with highs in the teens and 20s and
  overnight lows in the single digits above and below zero.

- Even colder temperatures will be possible during the
  Thanksgiving Holiday weekend, with forecast daytime highs in
  the single digits above some locations, and overnight lows
  below zero. Well below zero wind chill temperatures are also
  possible.

&&

.UPDATE...
Issued at 901 AM CST Fri Nov 22 2024

No major changes were needed for this update. Just blended in
the latest observations to the going forecast.

UPDATE
Issued at 539 AM CST Fri Nov 22 2024

No forecast updates. AFD updated for 12Z Aviation discussion
(below).

&&

.DISCUSSION...
Issued at 350 AM CST Fri Nov 22 2024

Currently, broad upper level ridge over the central CONUS early
this morning, with a large upper low over central Canada.
Resultant flow over the Northern Plains is zonal between these
two features, with surface high pressure drifting east across
the state. Mid level WAA spreading across western and central
ND, with current temperatures in the teens east with 20s west
closer to the sfc warm front.

Embedded mid level impulse sliding east over far south central
Canada, coupled with a cold frontal boundary dropping into
northern North Dakota, will bring a chance for some light snow
to far northern ND this morning. CAA will then push south across
western and central ND this afternoon, resulting in daytime
highs in the 20s north, but mild southwest (around 40) and
south central (low/mid 30s) where the CAA arrives later.

For tonight, another embedded impulse will move into the region
from the west, interacting with a subtle baroclinic zone to
bring a swath of light snow to parts of western and central
areas of the state. Best chances will be west-central and
northwest, with lesser chances to the east. Light snow will also
be more favorable this evening, with diminishing forcing
overnight as a mid level ridge builds into the western Dakotas
and a ridge of sfc high pressure builds southward into central
ND.

Ridge axis moves slowly east on Saturday as a strong upper level
jet associated with a long wave trough over the western CONUS
lifts east-northeast into the Northern Rockies. Embedded energy
ejecting out of the upper trough will morph into a closed low
over far south central Canada Sat night into Sunday, with an
associated inverted sfc trough draped over the Northern Plains
and the southern Canadian provinces of Saskatchewan and
Manitoba. Models have continue their trend of keeping the
heavier QPF/accumulating snow mainly to our north, with the NBM
and WPC guidance now only showing 1-2 inches across my northern
two-tier counties Sat through Sunday night.

CAA on Sunday on the back side of the sfc trough will see breezy
northwest winds, with daytime highs Sunday trending cooler from
Saturday, then much colder for Monday when highs are forecast
only in the teens and low 20s. Overnight lows Sun night will be
in the single digits above, with wind chills in the single
digits and teens below zero. Ridge of sfc high pressure looks to
bring even colder overnight lows for Mon night/Tues AM, with
lows in the single digits above and below zero.

Northwest flow aloft will then dominate through next week and
the Thanksgiving Holiday weekend, maintaining below average
temperatures. Ensembles and NBM are hinting at a couple of cold
air surges, one around Thanksgiving Day and another over the
weekend. While well below normal temperatures are favored (along
with well below zero wind chills), NBM 25/75 percentile spreads
remain 10-20 degrees, so still plenty of uncertainty a week to
10 days out regarding how cold temperatures will get. Multiple
shortwaves will also move through the region next week, each
bringing the chance for some light snow and a period of elevated
winds.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 539 AM CST Fri Nov 22 2024

VFR ceilings and visibility expected at all terminals this
Friday morning. Light snow is possible across the Canadian
Border this morning, but should remain north of KXWA and KMOT.
MVFR to IFR ceilings will begin to move into northwestern North
Dakota late this afternoon, spreading south and east through
the evening. Along with this, chances for light snow will
increase through the late afternoon and evening, with the best
chances at KXWA. Otherwise, light and variable winds are
expected to persist overnight, before organizing out of the
north through this afternoon and tonight.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

UPDATE...ZH
DISCUSSION...NH
AVIATION...NH