390
FXUS63 KBIS 090246
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
946 PM CDT Tue Oct 8 2024

.KEY MESSAGES...

- High temperatures will remain above average, reaching the
  upper 70s to upper 80s on Wednesday. Highs will then cool
  into the 60s for the end of the week, along with overnight
  lows in the lower to mid 30s.

- Generally light winds are expected through most of the week,
  but most locations will see breezy northwest winds on Thursday
  and Saturday as two different cold fronts move through.

- There is a low chance (15 to 30 percent) for some rain showers
  across the northwest and central on Saturday. Otherwise,
  expect mainly dry conditions.

&&

.UPDATE...
Issued at 945 PM CDT Tue Oct 8 2024

No changes to the forecast are needed. Quiet weather will
prevail tonight, with light winds and a clear sky.

UPDATE
Issued at 622 PM CDT Tue Oct 8 2024

With a clear sky and light winds expected through the night, the
low temperature forecast has been decreased to the 25th
percentile of NBM guidance across all of western and central
North Dakota, and as low as the 10th percentile for the Beulah
to Hettinger corridor. The forecast otherwise remains on track.

&&

.DISCUSSION...
Issued at 333 PM CDT Tue Oct 8 2024

This afternoon, an upper ridge axis was moving over western
North Dakota, and was placed in between two deep closed lows:
one over the Hudson Bay, and one off the coast of British
Columbia. At the surface, low pressure was analyzed well
northwest of the forecast area, with a stationary front oriented
northwest-southeast across North Dakota. Winds were southerly
on the east side of the front and west-southwest on the west
side, although still only around 10 mph. Sunny skies persist
this afternoon, with daytime highs in the mid 70s to mid 80s.
Quiet and clear weather will continue, with lows in the 40s.

Similar conditions are expected on Wednesday as the upper ridge
is shallow but persistent across the area. We did skew slightly
warmer in forecast high temperatures based on recent
verification, which puts highs in the upper 70s to upper 80s.
With a drier air mass, minimum relative humidity will drop into
the lower teens across southwest North Dakota, and in the 15 to
20 percent range across the west of western and most of central
North Dakota. The good news is that west/southwest winds will
be light, generally 10 mph or less.

Changes come on Thursday as a cold front drops south from the
Canadian Prairies, with forecast highs in the mid 80s southeast
to only around 70 degrees in the northwest. Breezy winds and a
shift to the northwest are expected, with sustained winds up to
20 mph and gusts up to 30. At the moment, it does not look like
the strongest winds (northwest) will line up with the lowest
relative humidity (18 to 20 percent south). However, there is a
bit of a signal in the southern James River Valley for potential
near critical fire weather, so will highlight in the HWO with
this update.

We still have a 15% chance of rain showers late Thursday night
behind the front, although the chance of any measurable
precipitation is low. Much cooler on Friday in the post-
frontal regime, with forecast highs in the 60s. A secondary,
more substantial cold front is projected to move through on
Saturday, bringing stronger winds and higher chances for
precipitation. Although northwest winds are favored to be in
the 20 to 25 mph range, with gusts to 35, higher relative
humidity should help limit fire weather concerns. Precipitation
chances are slowly increasing, around 50 percent in the
northeast part of the state, decreasing to the southwest. In our
counties the probability of at least 0.1" of rain is up to 30
percent in the Turtle Mountains area, and lower elsewhere.

Temperatures are trending cooler after the secondary push of
cold air, with overnight lows around freezing for most of the
area Saturday night. Forecast highs on Sunday could stay in the
50s for much of the area, before a trend towards warmer than
normal temperatures next work week.

&&

.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 945 PM CDT Tue Oct 8 2024

VFR conditions and light winds are expected through the forecast
period.

&&

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

&&

$$

UPDATE...Hollan
DISCUSSION...Jones
AVIATION...Hollan