814
FXUS63 KBIS 171729
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1229 PM CDT Sun May 17 2026

.KEY MESSAGES...

- Cooler with widespread rain showers and isolated
  thunderstorms today. The threat for severe weather is low.

- Medium to high chances (40 to 80 percent) for showers Monday
  afternoon through Monday evening. A few thunderstorms possible
  far south central into the southern James River Valley Monday
  afternoon.

- Cold overnight low temperatures near or below freezing tonight,
  Monday night and especially Tuesday night.

&&

.UPDATE...
Issued at 1214 PM CDT Sun May 17 2026

Another update mainly for pops based on latest radar loop.
Otherwise cloudy across the area with no other forecast changes
needed at this time.

UPDATE
Issued at 910 AM CDT Sun May 17 2026

For the mid morning update we adjusted pops based on latest
radar imagery. We also pushed the thunder north to the I-94
corridor this morning. Not sure if we will hear thunder in
Bismarck but there have been some pulses and a couple flashes in
the vicinity during the past hour. Better chances will be east
of Bismarck and south of the Interstate this morning.

UPDATE
Issued at 645 AM CDT Sun May 17 2026

A band of rain continues to develop across western North Dakota,
with dry air slowing its progress eastward. The low pressure
system bringing this rain should still kick this band eastward
today. Overall made some minor changes to PoPs based on current
radar trends.

&&

.DISCUSSION...
Issued at 340 AM CDT Sun May 17 2026

Surface low ahead of a broad upper trough is still forecast to
move through the state today. The result will be widespread rain
chances from west to east, although dry air at the surface may
limit coverage initially this morning. Even with dry air this
morning NBM still putting a 50 to 90% chance for at least a half
inch of QPF within the next 24 hours across much of the state
except for southwestern and portions of far western North
Dakota. Isolated thunderstorms also remain possible today.
Followed SPC`s general risk for thunder mention in the HWO which
is generally along and east of Highway 83, however, the
slightly better instability today is generally from Bismarck to
Jamestown and south, which is where the current forecast has
thunder mention. Thunderstorms in general today will be
isolated, and the threat for severe weather is low. Some breezy
easterly winds will also be found today, while cooler high
temperatures in the 40s north to the 50s south are found.
Tonight, initial push of showers will push eastward out of the
CWA this evening, while isolated to scattered shower activity
may remain through the night in the northwest and north central
associated with the upper level trough. Some snow may mix in at
times with these showers, although QPF and snow accumulations
looks low. Elsewhere, abundant low level moisture will keep low
clouds and perhaps bring slight chances for drizzle or patchy
fog. These areas are removed enough from the upper trough or
surface low to make confidence too low to include drizzle
mention, while a steady north wind should limit fog formation
tonight. Lows tonight will generally be in the 30s, with limited
frost potential given the steady winds, abundant clouds, and
lingering precipitation chances. Upper trough moves through the
state on Monday bringing a secondary round of rain showers with
perhaps a few isolated thunderstorms. Precipitation with this
second wave look to be limited with NBM chances for 0.5 inches
around 5 to 20 percent and generally just in the south and east.
A breezy north wind may be found for much of the area Monday,
while cool high temperatures in the mid 40s to mid 50s are
forecast. Showers become isolated Monday night, while low
temperatures again remain in the 30s with perhaps some upper
20s. There is some frost potential in the west Monday night,
although cloudy skies still look to limit this. Abundant low
level moisture will also remain Monday night, perhaps bringing
more low clouds, patchy fog, or even pockets of drizzle.
Precipitation chances then diminish Tuesday, while cooler
temperatures remain with highs forecast in the 50s. Some breezy
winds could be found in the east. Tuesday night into Wednesday
morning, clearing skies with lows near or below freezing could
bring widespread frost or perhaps even freeze conditions.

Active northwest flow could bring a late spring pattern mid to
late this upcoming week. Southerly flow at the surface could
warm temperatures each day with highs in the 70s by the end of
the week, and lows in the 40s. Weak disturbances in this
northwest flow pattern will also bring near daily chances for
showers and thunderstorms. A slight lowering in afternoon
humidity values may also be found during this time period, yet
should still remain above 30 percent. This combined with a cool
and active start to the week should limit the fire weather
concerns this week.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1214 PM CDT Sun May 17 2026

Widespread MVFR to IFR ceilings are expected to develop and
remain through the 18Z TAF period.

Low stratus has been slow to develop across western and central
ND, compared to previous guidance. We are however, finally
seeing some IFR ceilings over western and south central ND. As
current activity lifts northeast, expect lower ceilings to
eventually develop behind the activity. Looking ahead guidance
suggests that once MVFR-IFR ceilings develop they will remain
through the 18Z TAF period. Bufkit soundings suggest mainly
stratus instead of fog, but still can`t rule out some fog late
tonight into Monday morning. The exception may be the southwest
where there is some potential for clearing this afternoon, which
could result in a better chance of some radiation fog. Guidance
isn`t hinting at this yet.

In general expect an easterly to northerly surface flow,
becoming mainly northerly this evening. The exception is the far
southwest which will be mainly a northwest flow.

&&

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

&&

$$

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