000
FXUS63 KBIS 220931
AFDBIS
Area Forecast Discussion
National Weather Service Bismarck ND
331 AM CST Thu Dec 22 2016
.SHORT TERM...(Today and tonight)
Issued at 327 AM CST Thu Dec 22 2016
Currently...mild pacific high pressure encompassed much of the
western US, with low pressure over central/northern Canada moving
east. This has set up a fast westerly upper/mid/low level
flow
across the Northern Plains. West to southwest winds across western
and central ND ranged from mainly 5 to 20 mph, and were mixing the
lower
atmosphere and keeping temperatures in the teens and 20s.
Warm
advection today from the southwest should allow temperatures to
rise into the mid and upper 30s in the southwest...and in the lower
30s north and east of the Missouri River.
Tonight a cold
front extending from the central/northern Canadian
low moves southeast and approaches northwestern ND towards daybreak
Friday. Light winds and fairly clear skies should allow temperatures
to drop to 5 to 15 across western and much of central ND.
.LONG TERM...(Friday through Wednesday)
Issued at 327 AM CST Thu Dec 22 2016
A potential major Christmas winter storm highlights the long term
forecast...with significant accumulating snow, strong winds, and
blowing snow in the forecast. A
blizzard watch will be issued for
western and central ND from Christmas (Sunday) morning through noon
on Monday.
On Friday a fast-moving
upper level shortwave and associated cold
front will sweep southeast across ND. High temperatures will be
seasonable with highs mainly in the 20s and lows Friday night around
5 to 10 above zero.
Brief
upper level ridging occurs early Saturday before southwest
flow develops Saturday night (Christmas Eve). This is in response to
the longwave
trough that arrives at the west coast Friday night and
continues
deepening as it begins crossing the Rockies on Saturday.
As the
trough continues to deepen, expect an
upper level low to
close off near the base and lift north northeast into the
central and northern plains states.
Cyclogenesis will develop an
associated surface low on the
lee side of the Rockies. Chances of
light precipitation will begin in northwestern and north central
ND Saturday afternoon with the initial arrival of
shortwave
energy and lifting along a low level frontal boundary that sets
up across northern ND.
As we move into the overnight hours on Saturday and into Sunday
(Christmas Day), the surface low will continue to deepen as it lifts
northeast into South Dakota. Over the last several runs, models have
come into better agreement regarding precipitation location, with
growing confidence that this has the potential to become a
widespread and significant winter storm across the northern plains.
Confidence has increased again with the 00z model suite for today`s
forecast package. We think there is a better than 50% chance of
significant snowfall, strong winds, and
blowing snow over most, if
not all, of western and central ND.
The GEFS plumes continue to suggest 0.8 to 1 inch of liquid precip
at Bismarck and 1 to 1.2 inches at Jamestown. A widespread area of
6+ inches of accumulating snow is forecast Saturday night through
Monday morning. The strongest winds are forecast to occur on
Christmas Day in the afternoon, and especially Christmas night
(Sunday night) before decreasing gradually on Monday.
The storm will depart the region by late Monday, with colder
conditions on the back side. The cold will be short lived, as
temperatures will
likely moderate again by the middle of the work
week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
Issued at 1216 AM CST Thu Dec 22 2016
Expect
VFR conditions at all sites through the period. A west to
southwest surface
flow should persist through Thursday evening.
Strong west winds aloft will create some low level wind
shear this
morning.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
Blizzard Watch from Sunday morning through Monday morning for
NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.
&&
$$
SHORT TERM...JV
LONG TERM...JV
AVIATION...JV