National Weather Service National Headquarters

• Home
• Site Map
• News
• Organization
• Search for: NWS All NOAA 

000
FXUS63 KBIS 240246
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
946 PM CDT Sun Sep 23 2018

.UPDATE...
Issued at 939 PM CDT Sun Sep 23 2018

Little change with this update. The HRRR/RAP/GFSLamp/NBM through
their 01 UTC iterations continue to favor an expansion of fog
across the Missouri Coteau, into the Turtle Mountains and the
Upper James River Valley through 07 UTC. This is in line with
observed trends through 230 UTC. Thereafter, as winds become
northwest, fog may diminish late tonight into early Monday
morning. However, the higher terrain of the southwest may remain
in fog past sunrise Monday morning. Will monitor trends should a
Dense Fog Advisory become necessary. Have handled with an SPS for
now.

UPDATE Issued at 653 PM CDT Sun Sep 23 2018

The RAP/HRRR/GFSLamp/NBM through their 22 UTC iterations favor fog
development late this evening and overnight along the Missouri
Coteau, the Turtle Mountains, and the upper James River Valley,
with a more patchy signal across southwest North Dakota. Fog is
expected to decrease late tonight into early Monday morning as
surface winds become northwest.

&&

.SHORT TERM...(This evening through Monday)
Issued at 234 PM CDT Sun Sep 23 2018

The main focus for the short term is precipitation chances and
fog. Tonight, an upper level trough will approach North Dakota. As
a result light precipitation is possible over much of North Dakota,
beginning in the northwest late this afternoon and spreading
south and east tonight. The best chances will likely hold off
until late tonight/Monday morning over the James River Valley.

Weak winds will allow fog to develop once again tonight as a cool
and moist boundary layer remains. The short-term models have fog
redeveloping around sunset tonight mainly along the valleys and
pothole region.

.LONG TERM...(Monday night through Sunday)
Issued at 234 PM CDT Sun Sep 23 2018

Cool and active in the long term period as we remain within a
northwest upper level flow pattern through the work week. Another
wave will move into the northern Plains Monday evening, this will
bring another shot of light precipitation across the area Monday
night.

Tuesday through Thursday will be rather breezy. There is a chance
for precipitation each day this week. Some snow flakes may mix in
with rain Friday/Saturday mornings. Temperatures will remain
chilly this week with highs mainly in the 50s and lows in the 30s
to lower 40s. Even colder air will spill into the area behind the
Thursday system, and the potential for overnight lows below
freezing will exist through the weekend.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 939 PM CDT Sun Sep 23 2018

Widespread IFR stratus will continue late this evening and into
the overnight across most of western and central North Dakota. Fog
is also expected to expand late this evening and tonight across
most of the area. Stratus is likely to remain across northwest
and central North Dakota through Monday morning, and possibly
continuing into the afternoon across the north. Scattered rain
showers are possible Monday morning far south central and across
the James River Valley. Cumulus around 4000 ft AGL will develop
southwest and south central Monday afternoon with scattered rain
showers southwest.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...PA
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...PA