538
FXUS63 KBIS 241127
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
627 AM CDT Sun Aug 24 2025

.KEY MESSAGES...

- Well below average temperatures today and Monday then a
  gradual warming trend.

- Monday morning lows mostly in the upper 30s to mid 40s, but
  with some mid 30s possible west and central.

- Low chances for showers and thunderstorms return late in the
  work week.

&&

.UPDATE...
Issued at 609 AM CDT Sun Aug 24 2025

No changes to the early morning update. It`s a chilly start to
your Sunday morning, especially in the northwest. Crosby is
currently at 34 degrees and Tioga is setting at 37. One of the
usually colder NDAWN sites has dropped into the lower 30s.

Another cool but pleasant day is expected today with highs in
the mid 60s to lower 70s.

&&

.DISCUSSION...
Issued at 340 AM CDT Sun Aug 24 2025

Currently, surface high pressure was situated over southern
Saskatchewan and south into eastern Montana and the western and
central Dakotas. Skies were clear over much of the western
Dakotas, with scattered mid level clouds drifting south across
the eastern Dakotas. Temperatures as of 3 AM CDT ranged from
the lower 40s to mid 540s across western and central ND. There
were a few upper 30s over the far northern portion of the CWA.

For today, look for a cold start to the morning, with
temperatures climbing into the mid 60s to lower 70s. It will be
sunny across the areas this morning, but with some diurnally
driven cumulus resulting is partly cloudy skies over central ND
from late morning through mid afternoon. It will not be as
breezy today in eastern portions of the forecast area making for
a pleasant, albeit cool day across the forecast area. Normal
highs for this time of year are right around 80 degrees.

The aforementioned surface high slides southeast today and
tonight and is situated over the eastern Dakotas by Monday
morning. This should make for another cold start to the day
Monday morning. Given the favored position of the surface high,
generally light winds and mostly clear skies, we utilized a
blend of the NBM 10th and NBM25th percentile for morning lows
(as was the case with the previous forecast). This is resulting
ins a few areas of mid to upper (mainly upper) 30s over our
normally cold areas west of the Missouri and in the far north.
With the dry airmass over the area, frost is not anticipated to
be a big issue, however some patchy frost in low lying and
protected areas of our normally cool spots west of the river and
in the far north is certainly not out of the question. At this
time though, the areal extent would be too low for a Frost
Advisory.

After the cold start Monday, look for a gradual warm-up through
mid-week. It`s during this timeframe that the upper level low
over Ontario moves east and upper level ridging over the
Western U.S. seeps slowly eastward across the Rockies and into
western portions of the Plains States. This results in the
gradual warm-up with building upper heights and a return to a
southerly surface flow over the local area. Then as we go
through the second half of the work week and approach the
weekend, there are some more uncertainties that enter the
forecast. Basically the latest clusters are favoring (75% vs
25%) a warmer and drier end of the work week compared to a
cooler and wetter end of the work week. The cooler/wetter
solution is by no means a washout, and the warmer/dryer solution
is also not a scorcher. NBM ensemble spreads increase a bit
late in the work week but are not all that wide. NBM Pops have
increased a bit from yesterday but are currently only a low
probability (less than 40 percent) Friday and Saturday. We will
see how things play out but overall a cool start to the week
ahead with gradual warming through the week and some low
chances for showers and thunderstorms later in the work week and
into early portions of next weekend.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 609 AM CDT Sun Aug 24 2025

VFR conditions are expected at all TAF sites through the 12Z
TAF period. Mostly clear skies expected this morning. Diurnal
CU will develop late this morning over central and eastern ND
with the potential for a period of some low VFR ceilings at
KMOT and KJMS this afternoon. Less sky cover expected at KBIS,
and mostly clear skies expected over western ND including KXWA
and KDIK. Surface flow generally northwest over central ND at
12kts or less, and shifting more north this afternoon and light
and variable this evening. Generally light and variable winds
this morning at KXWA and KDIK, becoming more east to southeast
by this evening and overnight.

&&

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

&&

$$

UPDATE...TWH
DISCUSSION...TWH
AVIATION...TWH