896
FXUS63 KBIS 260727
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
227 AM CDT Sat Sep 26 2026

.KEY MESSAGES...

- Medium to high chances for light rain across central North
  Dakota overnight.

- Temperatures favored to remain near to slightly above average
  until late next week.

- High chances for showers and thunderstorms Sunday evening
  through Monday night for all but northwest North Dakota.

&&

.UPDATE...
Issued at 226 AM CDT Sat Sep 26 2026

An area of light rain associated with a mid level shortwave has
tracked farther west than guidance had indicated, roughly along
and between Highways 83 and 281. PoPs have been updated to
reflected observed conditions and trends. The only other
notable change for this update was to expand the mention of
patchy fog to as far north and west as Mountrail County, and
separately against the southern slopes of the Turtle Mountains
due to orographic ascent from south- southeast surface winds.
Coverage of fog was also upgraded to areas in parts of south
central North Dakota where rapid refresh guidance has been
consistent with reduced visibility.

UPDATE
Issued at 1004 PM CDT Fri Sep 25 2026

Some sprinkles and light rain showers continue to develop across
central ND ahead of an upper level wave. These could linger into
the early overnight hours before this upper wave makes more
consistent rain showers across the east. Latest CAMs also
suggesting a few isolated thunderstorms are possible across the
west early Saturday morning from a passing cold front and some
elevated instability. Made some minor PoP adjustments based on
both of these disturbances.

UPDATE
Issued at 638 PM CDT Fri Sep 25 2026

Low level moisture will continue to stream into the area this
evening, bringing some lower clouds and perhaps a few slight
rain showers and sprinkles. More organized rain showers are then
possible tonight into Saturday morning, mainly across eastern
portions. Some patchy fog is again possible tonight, although
confidence is not as high as in previous nights. Overall just
added in some sprinkle mention through the evening with some
light returns currently showing up on radar ahead of the upper
level wave. Otherwise the forecast remains on track.

&&

.DISCUSSION...
Issued at 1259 PM CDT Fri Sep 25 2026

Currently, low cloud remains across central and eastern North
Dakota, with only some high clouds in the west. Temperatures
were mainly in the 60s , except low to mid 70s under the more
abundant sunshine out west.

For tonight, most guidance suggests that the stratus will work
back to the west as a south to southeast return flow strengthens
over North Dakota ahead of a surface low situated over western
Canada. We do not anticipated widespread dense fog like we have
seen the past two mornings because of the increasing surface
gradient. However, some patchy fog can not be ruled out.
Guidance has been suggesting southern portions of the forecast
area, and added a mention of patchy fog later tonight into
Saturday morning. Latest guidance also keeps the mention of rain
from the Turtle Mountains into the James River Valley and
eastward late this afternoon through tonight. There is a
timeframe later this evening where low pops do extend back to
near the Missouri River in the south central, before shifting
back to the east after midnight. With the saturated lower layers
and some weak low level omega, we could see some patchy drizzle
extending west of the main precipitation area, to the Highway
83 corridor. Will monitor, but too uncertain to add a mention at
this time. On Saturday, the cold front associated with the
Canadian low pressure system swings west to east through the
forecast area. This will clear out the low stratus and shift
winds from southerly to northwest. Although it won`t be much
colder behind the front, it will be noticeably drier. Highs will
be mainly in the upper 60s to mid 70s across the forecast area
Saturday. Look for breezy southerly winds central early in the
day and breezy northwest winds over western ND late morning and
into the afternoon. High pressure builds over the area Saturday
night through a good portion of the day Sunday. Look for lows in
the lower 40s to lower 50s Saturday night and highs on Sunday
in the mid 60s to lower 70s.

Another upper level trough then looks to impact our weather
later in the day Sunday, through Monday night. A lead shortwave
propagating through a northern California upper trough will
induce cyclogenesis over the central High Plains, with an
inverted surface trough extending into the northern Plains by
early Monday. A northern stream wave may induce convection over
the Mondak region late Sunday, and into Sunday evening. Strong
bulk shear will be situated over the area. MLCAPE of
500-1000J/KG lifts from South Dakota into southwest ND Sunday
afternoon. Currently we have a general thunderstorm risk form
SPC Sunday. A stronger storm can not be ruled out with some hail
the most likely threat due to the likely elevated nature of the
storms. The entire system spreads east Sunday night through
Monday. Monday afternoon into early Monday may be another
potential for stronger storms as strong bulk shear weakens a
little but instability maybe greater from the south central into
the James River Valley. As mentioned in the previous
discussion, anomalously high Precipitable Water values and
possibly some training storms, may result in efficient rainers
with locally heavy rainfall Sunday night through Monday night as
the system works it`s way east across the forecast area.

We then dry out, at least for a while with a quasi-zonal flow
over the region and temperatures remaining near normal with
highs in the 60s to lower 70s and lows in the 40s through the
middle portion of the workweek.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 226 AM CDT Sat Sep 26 2026

Low ceilings will prevail over most of western and central
North Dakota through tonight, clearing from west to east during
the day Saturday. The clearing may not reach KJMS until Saturday
evening. Light rain showers will move northward through central
North Dakota overnight, and additional showers could develop
back towards KJMS. Rain is unlikely to cause categorical
restrictions lower than those caused by ceilings. Patchy fog or
mist could also develop late tonight into Saturday morning,
mainly across southern North Dakota. Southeast winds will
remain breezy into early Saturday morning. A cold front will
enter western North Dakota Saturday morning, turning winds to
the west-northwest around 15-20 kts with a few higher gusts.
The front should reach central North Dakota Saturday afternoon,
but with lighter west-northwest winds there.

&&

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

&&

$$

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