129
FXUS63 KBIS 151140
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
640 AM CDT Tue Sep 15 2026

.KEY MESSAGES...

- Strong westerly winds diminish this morning.

- Near normal temperatures in the mid 60s to mid 70s through
  the week.

- Mainly dry today, low chances for showers Wednesday. Better
  chances for showers and thunderstorms approach the area late
  in the work week and into the weekend.

&&

.UPDATE...
Issued at 638 AM CDT Tue Sep 15 2026

We have cancelled remaining portion of the Wind Advisory in
central ND. Otherwise, made some minor adjustments to sky cover
based on latest satellite imagery.

&&

.DISCUSSION...
Issued at 204 AM CDT Tue Sep 15 2026

Strong low pressure over southeast Manitoba will quickly scoot
east through Ontario, with winds diminishing over central and
eastern ND this morning.

As of 2 AM CDT, winds were gusting to 45 to 50 mph over central
ND, with an occasional gust up to 55 mph. We extended the Wind
Advisory through 7 AM CDT for central ND. Pressure fall rise
couplet will be well east of the area by this time and expect we
should be able to let the advisory go by then. There were a few
showers earlier overnight around the Turtle Mountains and there
could still see a few sprinkles across the far north early
this morning, but showers dropping south over southern Manitiba
and Saskatchewan continue to dissipate as they approach the
International Border. Will begin with a dry forecast today.
Winds diminish through the morning and by late afternoon into
the early evening, they shift to the east. Look for considerable
cloudiness this morning, especially north, giving way to
sunshine this afternoon. Areas in the far south will likely see
abundant sunshine today. High temperatures today will be mainly
in the 60s, with a few upper 50s possible around the Turtle
Mountains area.

Winds pick up from the southeast later tonight in the west,
ahead of another area of low pressure developing over northern
Wyoming and southeast Montana. The surface low remains to our
south as it ejects into the Plains on Wednesday, but with an
inverted trough northward into western ND. Strong warm advection
combined with a weak shortwave traversing the area may spark a
few showers Wednesday morning from western into central ND. A
northern stream shortwave then provides additional forcing
across the northern tier counties late morning and into the
afternoon, supporting medium chances for convection across the
north, with low chances lingering over the south central.
Thunderstorm chances will be negligible early in the day, with
some elevated instability available over central ND by the
afternoon. SPC has a general risk of thunder over central ND
Wednesday and this seems reasonable. It will be breezy southwest
and south central Wednesday with southeast winds ahead of the
inverted trough. There may be a period of breezy northerly winds
late Wednesday afternoon into Wednesday evening, on the back
side of the inverted trough. High pressure then builds over the
area Wednesday night with cool and quiet weather into Thursday
morning. Some patchy frost may be possible over the northwest
early Thursday morning.

An upper level low pressure system then moves across the Rockies
and into the Northern High Plains late in the work week into the
weekend. A leading shortwave tracks south of the state Thursday
afternoon through Friday morning, keeping precipitation chances
mainly south of the state. An isolated thunderstorm could sneak
into the southwest late Thursday afternoon into Thursday
evening. Then later Thursday night low precipitation chances
move into western ND ahead of the main upper low. The low moves
into eastern Montana Saturday then into the Western Dakotas
Sunday. This will keep chances for showers and thunderstorms
over the western half of the state through a good portion of the
weekend. The upper low then drops south of the area later
Sunday night into Monday morning. This will keep precipitation
chances over the south central on Monday, while the west and
north central begin to dry out.

The potential for strong to severe storms looks limited with
this system due to our cooler daytime highs and lack of strong
moisture transport into the forecast area. We do see a decent
moisture return Friday with dewpoints climbing into the lower
60s, and with the slow progression of the upper low through the
weekend, we could see some decent rainfall amounts over western
ND before all is said and done. Currently the NBM is depicting
moderate chances (40 to 60%) for at least a half inch of rain
for the 48 hour period ending at 7 AM Sunday, south of the
Highway 2 corridor and west of the Highway 83 Corridor.
Probabilities taper to low from the Turtle Mountains into the
James River Valley.

High temperatures through the forecast period are expected to
be generally in the mid 60s to mid 70s with overnight low
temperatures generally in the 40s to lower 50s, although
Wednesday night into Thursday morning may bring some mid to
upper 30s to northern portions of the state, with some patchy
frost.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 638 AM CDT Tue Sep 15 2026

Northwest winds will continue to diminish this morning, becoming
light and variable by later this afternoon, then becoming easterly
this evening. Scattered MVFR ceilings are expected this morning,
with more areal coverage across the north. MVFR ceilings are
expected to lift and/or dissipated by early this afternoon across
the forecast area, with VFR conditions thereafter. Expect increasing
mid and high level clouds later tonight with showers possible over
the northwest into central ND towards the end of the TAF period.
However, too much uncertainty at this time to include in any
TAF.

&&

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

&&

$$

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