612
FXUS63 KBIS 301056
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
556 AM CDT Tue Sep 30 2025

.KEY MESSAGES...

- Mostly dry conditions continue through the middle of the week,
  though a few stray showers, perhaps with a rumble or two of
  thunder, are possible.

- Above average temperatures and breezy conditions continue
  through the middle of the week.

- Cooler, more seasonable conditions, and 20 to 40 percent rain
  chances return at the end of the week.

&&

.UPDATE...
Issued at 556 AM CDT Tue Sep 30 2025

The forecast remains on track.

&&

.DISCUSSION...
Issued at 414 AM CDT Tue Sep 30 2025

Ridge off upper level high pressure over the Great Lakes Region
will keep amplifying through Wednesday night. After which,
shortwave energy passing through Southern Canada and the
Northern Plains Thursday will begin breaking it down. This will
keep the state in southwesterly flow aloft through Thursday
night. Simultaneously, surface high currently over Ontario will
gradually churn eastward over Quebec before diving southeastward
into the northeastern CONUS on Thursday. This will allow
relatively warm and moist southerly flow at the surface to
prevail more often than not. All in all, unseasonably warm
temperatures will continue through mid-week with highs in the
upper 70s to mid 80s, and lows mostly in the mid 50s to low 60s.

There is a very low chance a few rogue showers could pass
through the James River Valley and up through the Turtle
Mountains later this afternoon and into the overnight hours.
However, better chances are east of the forecast area and closer
to the ND/MN border. Another round of showers, possibly with a
few rumbles of thunder, is possible Wednesday morning as
shortwave energy rides up the western periphery of the
aforementioned ridge. Should any showers and thunderstorms
occur, they will mainly be confined to western ND.

Higher shower and thunderstorm chances, albeit still only around
the 20 to 40 percent range for any given area at any given
time, are in the forecast early Friday morning through at least
the weekend. However, high uncertainty remains on this as most
global models suggest a split-flow pattern, at least initially,
as a trough digs into the west CONUS. After which, a more
organized trough may lift up through the region. Deterministically,
this is resulting in wetter solutions among the GFS (including
the GEFS Plumes) and Canadian solutions, while the EC supports a
more progressive, open wave with little rainfall in the state.
Overall, the NBM seems to favor the GFS/Canadian solution at
this point in time. Regardless of whether or not rain occurs in
any particular area, there is high confidence in a return to
more seasonable temperatures this weekend and into early next
week.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 556 AM CDT Tue Sep 30 2025

VFR ceilings and visibility are expected through the period.
For this morning, pockets of LLWS remain over parts of central
ND, potentially impacting KBIS and KMOT, though will diminish
as the sun rises and surface winds increase. Additional pockets
of LLWS are possible tonight. However, just how pronounced LLWS
tonight becomes remains in question since it`s mostly speed
rather than directional shear. Or in other words, it is highly
dependent upon how light surface winds become. Therefore, left
out of TAFs for now.

&&

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

&&

$$

UPDATE...Telken
DISCUSSION...Telken
AVIATION...Telken