231
FXUS63 KBIS 061948
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
248 PM CDT Sat Jun 6 2026

.KEY MESSAGES...

- Highs in the mid 80s to mid 90s today. Windy across western
  and central North Dakota, with a Wind Advisory in effect.

- Isolated to scattered severe thunderstorms are possible over
  western and parts of north central North Dakota tonight.

- Scattered to numerous severe thunderstorms over much of
  western and central North Dakota Late Sunday afternoon and
  Sunday night.

- Except for a brief break on Monday, a more active severe
  weather pattern looks to continue next week.

&&

.DISCUSSION...
Issued at 248 PM CDT Sat Jun 6 2026

This afternoon, shallow ridging aloft was moving over eastern
North Dakota, while upstream of the forecast area a deep closed
low was analyzed over the Pacific Northwest. At the surface, low
pressure was located in northeast Wyoming, with southerly low-
level flow across North Dakota. A tightening pressure gradient
is producing strong southeast winds, and a Wind Advisory is in
effect through late this evening for areas south and west of the
Missouri River.

Mostly quiet weather is expected for the remainder of the
daytime hours, with eyes on a shortwave moving through Montana
and convection developing west of the forecast. Latest CAMs runs
are in relatively good agreement on the main area of storms
extending across northwest North Dakota late this evening and
into the overnight hours along a surface trough, with
potentially some additional showers and thunderstorms across the
southwest where the environment is less favorable. In the
northwest, we continue to advertise hail up to the size of ping
pong balls and winds up to 70 mph. Forecast parameters are a bit
tough, with stronger shear to the west and higher instability to
the east, but the narrow area of overlap favored across
northwest North Dakota would be supportive of severe
thunderstorms if they develop and can survive capping advertised
in forecast soundings.

Numerous severe thunderstorms are possible on Sunday (level 3
out of 5) which is an upgrade from the previous shift. Sharp
southwest flow aloft will overlap with another surface low and
associated fronts from eastern Montana through much of North
Dakota. Ahead of the cold front will be a very warm and moist
airmass, with forecast dew points in the upper 50s to lower 60s
and strong southeast winds across central and eastern North
Dakota, which will likely need another Wind Advisory. As the
front moves east through the afternoon and evening, a big
question is the potential capping inversion and if temperatures
will heat up enough to overcome the cap. Right now, forecast
high temperatures are in the mid to upper 90s across central
North Dakota, slightly lower in the James River Valley, and in
the mid to upper 80s across the west behind the front.
Convective temperatures are generally from 94 to 97 F, so it
will be close. If any initial supercells develop, they would
likely be across northern North Dakota, and bulk shear vectors
parallel to the front would favor discrete cells. These storms
would be where the primary large hail (up to 2 inches) and
potential tornado threat would be, although low-level SRH is
still somewhat marginal. High-res guidance is pretty split on
what develops in the late afternoon, but is coming into more
agreement on storms moving into southwest North Dakota in the
evening. The mean wind quickly turns southerly along and behind
the front which would favor upscale growth and a wind threat.
Deterministic guidance is advertising DCAPE over 1000 J/kg and
0-3km shear around 25 knots, so sticking with the 70 mph wind
speed in messaging for now although can see this having to be
increased if we get more confident in linear mode and the 0-3km
shear increases a bit more.

We get a break from precipitation chances on Monday as the
upper low lifts to the northeast, with a brief reprieve from the
hot and humid airmass from this weekend. Forecast highs on
Monday are in the mid 70s to lower 80s, with light surface winds
as a weak surface high passes through the region.

Tuesday is the next day to pay attention to for potential severe
thunderstorms. Persistent southwest flow combined with a surface low
and attendant upper wave is a favorable synoptic setup for
convection, and although it`s still early, deterministic guidance is
advertising a very sufficient environment for severe thunderstorms
to develop, with forecast dew points in the 60s across much of
the state. CSU machine learning probabilities have jumped up
significantly from yesterday, so will be interesting to see how
this trends the next few days. NSSL ML probabilities are also
modest and highlight most of North Dakota for this period.

As the system from Tuesday continues to move through on Wednesday,
severe weather probabilities shift further to the east. NBM
precipitation chances keep low to medium probabilities of showers
and thunderstorms through Wednesday and into Thursday, although a
lack of instability will limit the severe weather potential for the
forecast area. Flow aloft turning more northwesterly will also help
cooler air filter into the region, with widespread highs in the 60s
and 70s by late in the week. Extended outlooks tilt towards below
normal temperatures through the middle of the month.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1251 PM CDT Sat Jun 6 2026

Generally VFR conditions expected through the TAF period. The
main exception will be the potential for showers and
thunderstorms at KXWA and northwest ND this evening, with a
PROB30 group for this terminal. Expect gusty and erratic winds
near any thunderstorms and IFR-MVFR visibilities with heavy rain
associated with any storms. These storms could be severe.

Breezy to strong southeast winds will continue through much of
the TAF period, strongest south and west of the Missouri River
with sustained winds around 30 mph and gusts up to 45 mph.
Southeast winds diminish some tonight but strong southerly
winds aloft will necessitate a mention of LLWS at all TAF sites
except KXWA. Late in the TAF period, winds start to shift
northwesterly across far western North Dakota.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until midnight CDT /11 PM MDT/ tonight for
NDZ017>020-031>033-040>044-059>062.

&&

$$

DISCUSSION...Jones
AVIATION...Jones