975
FXUS63 KBIS 222339
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
639 PM CDT Fri Aug 22 2025

.KEY MESSAGES...

- Well below average temperatures Saturday through Monday, with
  highs mostly in the mid 60s to mid 70s and lows in the 40s.

&&

.UPDATE...
Issued at 639 PM CDT Fri Aug 22 2025

Winds have fallen below Wind Advisory criteria and will continue
to diminish this evening, therefore canceled the advisory a
couple hours early. Otherwise, the forecast remains on track.

&&

.DISCUSSION...
Issued at 245 PM CDT Fri Aug 22 2025

The northern Plains lies under the auspice of a stacked upper
level low crossing the Canadian Prairies this afternoon,
turning flow aloft northwesterly. Moisture wrapping around this
low will promote increasing cloud cover and low chances (10 to
20 percent) for light showers this afternoon through early
tonight, mainly across the north and east. At the surface, the
tightening of the pressure gradients between an incoming area
of high pressure butting up against the stacked low is promoting
moderate winds across portions of central North Dakota this
afternoon. This, in combination with modest CAA advection and a
developing LLJ, will promote sustained speeds around 25 to 30
MPH and gust up to around 45 MPH anticipated this afternoon
through the early evening. Thus, a Wind Advisory will remain in
effect through early this evening. Otherwise, seasonably cool
high temperatures in the upper 60s northwest to lower 80s south
are found across the forecast area today.

Flow over the northern Plains is anticipated to remain
northwesterly to near meridional over the weekend, keeping
conditions cool and dry. High temperatures Saturday and Sunday
afternoons are forecast in the mid 60s to mid 70s, with low
temperatures are broadly in the 40s. Of note is the low
potential for anomalously cold temperatures overnight Sunday
through Monday morning. The ECMF EFI highlights a moderate minT
index deviation of around -0.7 to -0.8 across much of western
and central North Dakota during this period. An interrogation of
NBM clusters during this period reveals a small minority of
ensemble members (approximately 10 percent) which does promote
low temperatures around or even below 40 degrees Monday morning,
which could allow for some patchy frost during this period.
This cluster is greatly underdispersed, however, driven mainly
by ensemble members belonging to the GEPS, so take this
scenario with an even greater grain of salt than usual.

Looking ahead to next week, some amount of uncertainty builds
into the forecast as ensemble becomes increasingly split on the
evolution of a potential ridge building into the northern Plains
through the workweek. While almost all solutions maintains dry
and cool weather through the early half of the week as near
meridional flow persists, a majority of clusters (approximately
80 percent) keep this trend going as longwave ridging moves in
across much of the western and central CONUS. That being said, a
minority cluster also exists (approximately 20 percent of
ensemble members), which delays the expansion of the ridge into
the central CONUS until later toward the weekend, mainly due to
the aggressive southward development of a trough over Hudson Bay
and the Great Lakes Region. In this scenario, strictly
northwesterly flow over the northern Plains could allow near
daily chances for precipitation through the later half of the
workweek. For now, we will continue to advertise the NBM`s near
zero PoPs for this period. In either scenario a return, if still
slightly below normal, high temperatures broadly in the upper
70s and 80s and anticipated for next week.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 639 PM CDT Fri Aug 22 2025

VFR ceilings and visibility are expected through the period.
Gusty northwesterly winds will continue diminish this evening
across all but northeastern North Dakota. Breezy northwesterly
winds are then expected again for the eastern half of the state
Saturday.

&&

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

&&

$$

UPDATE...Telken
DISCUSSION...Adam
AVIATION...Telken