486
FXUS63 KBIS 151545
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
945 AM CST Sat Nov 15 2025

.KEY MESSAGES...

- Cooler and mostly dry this weekend, with a low to medium of
  chance of light rain in southwest North Dakota this afternoon
  and evening.

- Temperatures remain closer to average for the upcoming work
  week, with highs mostly in the mid 30s to mid 40s.

- Low to medium chances for light mixed precipitation Monday
  through Thursday. Little to no impacts expected at this time.

&&

.UPDATE...
Issued at 945 AM CST Sat Nov 15 2025

Generally quiet weather is found over western and central North
Dakota at the time of this mid morning update. Low level clouds
over the southwest have generally lifted, though a mid level
cloud deck continues to spread eastward this morning. To the
west of the forecast area, another area of shallow clouds and
modest reflectivities have developed in eastern Montana,
associated with a mid level jet and a thin band of 700mb FG
forcing. Both these features are anticipated to spread eastward
into the forecast area through this afternoon and evening,
promoting scattered showers for western and portions of central
North Dakota during this period. With this update, have blended
in the latest CAMs into the PoPs forecast, and have tweaked
cloud cover to account for satellite trends. Other than this
minor adjustments, the forecast remains on track at this time.

UPDATE
Issued at 555 AM CST Sat Nov 15 2025

A small area of light rain showers persists in the Standing
Rock Reservation at the time of this writing, but should soon
shift fully into South Dakota or dissipate. Low to mid clouds
continue to be more prevalent than guidance had suggested, but
there are now at least some breaks in the clouds. No major
forecast changes are needed for this update, but did throw in a
patchy fog mention for the southwest late tonight into Sunday
morning. This does seem like a favorable setup for fog formation
from differential cooling along the western edge of a stratus
shield, with light surface winds and low level subsidence.

&&

.DISCUSSION...
Issued at 357 AM CST Sat Nov 15 2025

North Dakota is under a zonal flow pattern this morning,
sandwiched between an upper level ridge over the Southern
Plains and an upper level low crossing northern Manitoba. A
cold front has passed southward through the state, and a
surface high pressure is currently analyzed over southwest
Saskatchewan/northeast Montana, drifting southeastward. The mid
to upper level cyclonic flow has maintained a large swath of
low to mid clouds across much of the region that models are
struggling to pick up on, lending to low forecast confidence in
their evolution.

The general expectation is that flow aloft will turn
northwesterly today as the surface high slides through Dakotas,
which should clear out at least some of the clouds from the
north and east. Southwest North Dakota is more likely to remain
cloudy through the day though, and an embedded low amplitude
shortwave traveling along a baroclinic zone with modest low
level frontogenesis could produce a band of light rain across
southwest North Dakota this afternoon, possibly shifting into
south central North Dakota this evening before dissipating
overnight. This signal has been consistent in high- resolution
guidance for over 24 hours, but with varying placement and
intensity of simulated reflectivity. Nevertheless, the maximum
HREF QPF with this system is only around a tenth of an inch,
and the probability matched mean is only a few to several
hundredths of an inch. Some snow could mix in along the colder
(northeast) side of the band, but no accumulation is expected.
High temperatures today will be significantly cooler but still
near to slightly above average, ranging from around 40 north to
near 50 southwest.

The southeastward progression of the surface high pressure is
forecast to stall tonight into Sunday as a trough digs into the
Great Lakes region. Meanwhile, a potent wave over California
will begin to spin northeastward and force amplification of an
upper level ridge along the eastern slopes of the Rockies. The
transition to an anticyclonic flow pattern should keep Sunday
dry and allow a slight warmup, although a southeast surface wind
is not favorable for strong diurnal mixing of the boundary
layer. Forecast highs for Sunday range from around 40 northeast
to the lower 50s southwest. There is also a signal for fog
formation in models that simulate visibility across parts of
western and south central North Dakota early Sunday morning,
but there is not enough spatial and coverage consistency to add
this to the forecast at this time.

Much of the upcoming work week is forecast to feature a
predominant split southwest flow pattern over the Northern
Plains. This results in daily low to medium chances for
precipitation, but with high probabilities for only light QPF
(less than 0.10" daily) where precipitation occurs. Thermal
profiles do suggest mixed types, including a potential for
freezing rain/drizzle. It is difficult to have high confidence
in any particular aspect of the precipitation forecast in this
type of synoptic pattern, but there is an emerging signal for
southern North Dakota to be on the northern periphery of a
compact shortwave Monday night into Tuesday that could provide
enough low level warm air and moisture advection for a light
rain/drizzle event, with near-freezing surface temperatures.
There is also agreement in ensemble clusters for a more
progressive, but still split-flow shortwave crossing the central
CONUS late Wednesday into Thursday. Cluster analysis does
indicate the northern stream could cross the state, but the
probability of over a tenth of an inch of QPF with this system
is only around 20 to 30 percent. Overall, the general
expectation is for a cooler and cloudier work week with periods
of light precipitation. Little to no impacts from frozen
precipitation types are anticipated at this time, but will need
to monitor the Monday night/Tuesday morning timeframe for a
freezing drizzle potential. Deterministic NBM highs are in the
mid 30s to mid 40s, but there is a large spread in the daily
maximum distributions, and deterministic values are skewed to
the warmer side. This conflicts with the anticipation of
increased cloud cover, so would not be surprised to see the
high temperature forecast trend cooler as the time approaches.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 945 AM CST Sat Nov 15 2025

Low ceilings in far southwest North Dakota should lift to at
least MVFR levels by late morning. Elsewhere, VFR ceilings could
prevail across much of the area, but do think there should be a
general clearing trend from the north and east through the
morning. VFR to MVFR ceilings are expected to return/persist
across much of western and south central North Dakota this
afternoon through tonight. A band of light rain could also
develop across southwest North Dakota this afternoon, shifting
into south central North Dakota while dissipating this evening.
Later tonight into Sunday morning, fog could develop again in
southwest North Dakota. Northwest winds around 10-15 kts with a
few 20 kt gusts across central and eastern North Dakota this
morning and afternoon, otherwise light and variable.

&&

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

&&

$$

UPDATE...Adam/Hollan
DISCUSSION...Hollan
AVIATION...Hollan