208
FXUS63 KBIS 242328
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
628 PM CDT Sat May 24 2025

.KEY MESSAGES...

- Isolated showers (20 percent chance) are possible today
  through Sunday night mainly south and west of the Missouri
  River.

- Patchy fog possible tonight southwest and south central.

- Isolated to scattered showers (20 to 50 percent chance),
  potentially with a rumble or two of thunder, are then possible
  Memorial Day through Wednesday across the area.

- High temperatures should remain fairly stable from around 60
  southwest to the low 70s northeast through early next week. A
  warming trend is then favored to finish out next week.

&&

.UPDATE...
Issued at 625 PM CDT Sat May 24 2025

Isolated showers have popped up south of Bismarck near SD, so
we maintained the 20 percent chance of showers in the south
central for a few more hours.


&&

.DISCUSSION...
Issued at 245 PM CDT Sat May 24 2025

The weather forecast should fairly quiet across western and
central North Dakota through the rest of the weekend and into
the next work week. The forecast area will generally be stuck
in a split flow regime aloft which will keep high temperatures
mainly in the lower 60s to lower 70s and only low to medium
chances for periodic rain showers through mid week.

At the upper levels, a shortwave is moving southeast across
northern South Dakota early this afternoon, only manifesting
itself in the form of cloud cover across southern North Dakota.
Clouds here should diminish a little bit through the day before
building back in later tonight and tomorrow. By the time we
reach peak heating today, most of the CAMs are showing some
isolated rain shower development, mainly southwest and south
central, so we decided to broad brush in isolated chances (20
percent) here. This activity should diminish as we start to lose
heating this evening.

Winds will become light and variable, but generally out of the
southeast, overnight. This factor, along with some clearing
skies, could end up leading to some fog formation across
western and central North Dakota, with CAMs suggesting the most
likely area being the southwest and south central.

Surface high pressure will dominate the weather pattern on
Sunday, but we could see another round of diurnal showers (20
percent chance) during the afternoon southwest and south central.
Highs will once again range from the lower 60s southwest, to
the lower 70s in the vicinity of the Turtle Mountains and Devils
Lake Basin.

Sunday night into Monday, an upper low will develop near the
Minnesota/North Dakota border in the weak split flow aloft. This
low will become cut-off, slightly retrograde west, and stall
out over the northern Plains/Upper Midwest through at least
Wednesday night, bringing slightly better chances of
precipitation (20 to 50 percent) at times to all of western and
central North Dakota (Sunday night through Wednesday).
Precipitation amounts are not expected to be all that impressive
with this system. The NBM is suggesting mainly a 20 to 50
percent chance for amounts of a least 0.10 inches but only a 10
to 30 percent chance for amounts of at least 0.50 inches. For
now, it appears the best chances will be across the southern
half of the state with amounts ranging from a few hundredths of
an inch to around a quarter of an inch or so. A thunderstorm or
two could be possible across the far south Tuesday night, but
chances are low for now as instability is forecast to be weak.

By the end of the week, ridging tries to nudge back in as we
move back into a traditional split flow setup aloft. This
pattern will also promote a warmup towards the end of the week
and into next weekend. Highs Monday through Wednesday will once
again warm into the range of the lower 60s to the lower 70s but
Thursday should be a little warmer with some lower 80s possible
again on Friday and Saturday.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 625 PM CDT Sat May 24 2025

VFR with patchy fog in the southwest causing IFR to LIFR VIS
late tonight and into Sunday morning. Winds will be mostly
light through the period.

&&

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

&&

$$

UPDATE...Smith
DISCUSSION...ZH
AVIATION...Smith