445
FXUS63 KBIS 290043
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
643 PM CST Fri Nov 28 2025

.KEY MESSAGES...

- Snow will continue over much of western and central North
  Dakota through tonight before ending later Saturday morning.
  Greatest snow amounts are expected over southwest and across
  portions of south central North Dakota, where a Winter Weather
  Advisory remains in effect.

- Well below average temperatures are favored this weekend
  into early next week. Wind chill temperatures as low as 25
  below zero will be possible both Saturday night and Sunday
  night.

&&

.UPDATE...
Issued at 643 PM CST Fri Nov 28 2025

A banded snowfall structure persists from roughly Glen Ullin to
St. Anthony, Linton, and Ashley as of 00 UTC, with reports thus
far under the band of up to 3.7 inches of snowfall at Glen
Ullin. Guidance including recent RAP/HRRR simulations have been
suggesting that frontogenesis has weakened in the last few
hours, but radar representation suggests that mesoscale forcing
is persisting in that band, with north-south oscillations to the
band owing to its internal dynamics. The right-entrance region
of a 60-90 kt 300 mb jet streak situated from eastern MT across
northern ND and into southern Manitoba may be effectively holding
this area of enhanced ascent in place, too. Still, given the
expectation of this mesoscale ascent gradually waning, and
climatologically-lower wind speeds with this event, we are not
yet upgrading to a Winter Storm Warning for heavy snow in that
axis. Nonetheless, the upstream shortwave trough and associated
strong Q-Vector convergence aloft is moving through eastern MT
and is expected to cross western and southern ND overnight with
persistent light to moderate snowfall. The KBIS 18z RAOB sampled
a modest dendritic growth zone aloft, but forecast soundings
are consistent in suggesting the dendritic growth layer will
deepen overnight, resulting in higher snow-to-liquid ratios
despite the somewhat meager liquid-equivalent moisture expected
with the main shortwave trough overnight. Some forecast
soundings show an archetype favorable for snow-to-liquid ratios
exceeding 20:1 by late tonight, which would favor low-density
but notable snowfall accumulations of a few additional inches.
We will continue to monitor that, but no significant changes
were made to the snow forecast with this update cycle. Changes
that were made include increasing precipitation (snowfall)
chances to 80-100% most of the night in much of western and
south central ND, and to add Burleigh and Logan Counties into
the existing Winter Weather Advisory. While there is not much
change to the previous snow forecast, observed travel impacts in
these counties are not too dissimilar than areas already in the
advisory, and persistence of the aforementioned banding
structure in parts of those two counties also favored adding
them into the advisory. In general, we still expect additional
accumulations in the advisory area to be in the 1 to 3 inch
range overnight, but with low to medium chances of locally
seeing up to 4 additional inches of snow.

&&

.DISCUSSION...
Issued at 226 PM CST Fri Nov 28 2025

The upper level pattern over North America currently consists
of ridging over the west coast, west-northwest flow over much of
the central region and a couple stronger embedded shortwave
troughs moving down the backside of that ridge, approaching the
Northern Plains tonight. The associated surface low was located
approximately over eastern Wyoming and Colorado resulting in a
generally east/southeast surface flow over ND. Warm air
advection/isentropic lift with some pronounced frontogenesis in
the 850-700mb layer earlier today supported a band of snowfall
over our southwest and south central counties with lighter snow
elsewhere. Model QPF has seemed a little high, probably more
noticeable with high SLRs, giving model total snow forecasts a
boost. So far the highest totals we have received have been
around 3". Surface obs, radar, DOT road condition reports and
plow webcams as well as NDAWN webcams support maintaining the
advisory as is. Locally Bismarck total snow forecast creeps into
advisory range, but with amounts over the remainder of the
county forecast to be less and based on upstream trends, will
not extend the advisory at this time. As mentioned in previous
discussions, soundings continue to show decent lift in the DGZ
this evening as temperatures through the profile drop. So
despite the relatively low QPF forecasts, it would not take much
to boost snow totals.

Otherwise, as synoptic scale lift depicted by Q-vector convergence
exits to our south late this afternoon, the upstream trough will
cross our area overnight, supplying another area of lift that will
support continued mostly light snow over much of our region.
Generally, looking at 1 to 4" of snow accumulation during the
overnight period, before the trough passes to our south and snow
ends on Saturday.

High pressure then builds in from the west later on Saturday into
Sunday, with dry and cold weather expected. Upper level flow will be
mostly northwest with some transient troughs and ridges resulting in
temperature fluctuations during the week. Sunday highs will be in
single digits above zero to the low teens southwest, with overnight
lows Saturday night and Sunday night dropping to the single digits
below zero. Temperatures moderate quickly by Tuesday before dropping
again just as quickly on Wednesday. NBM probabilities show higher
uncertainty by around Tue/Wed. Along with this pattern there are
periodic low chances for snow. However, at this time there are
no indications of any significant storms next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 643 PM CST Fri Nov 28 2025

MVFR to IFR conditions in snow are expected across much of
western and central ND tonight as a disturbance crosses the
area. Local LIFR conditions are possible in the most intense
snow bands, mainly in south central ND. Snow will gradually end
from west to east in the 12 to 18 UTC timeframe Saturday, but
there remain high probabilities for MVFR ceilings to persist at
most TAF sites in western and central ND through the end of the
00 UTC TAF cycle. East winds at 10-15 kt will gradually turn to
the north-northwest on Saturday at similar speeds.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 AM CST /5 AM MST/ Saturday for
NDZ017>020-031>035-040>047-050-051.

&&

$$

UPDATE...CJS
DISCUSSION...JNS
AVIATION...CJS