673
FXUS63 KBIS 140625
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
125 AM CDT Thu Aug 14 2025

.KEY MESSAGES...

- Thunderstorms possible tonight across the James River Valley. The
  chance of severe weather is low.

- Isolated to scattered severe thunderstorms possible Thursday
  afternoon and evening. Main hazards will be hail to the size
  of a golf ball and wind gusts to 70 mph.

- High temperatures in the 90s combined with increasing
  dewpoints could bring some moderate Heat Risk to central
  portions on Thursday.

&&

.UPDATE...
Issued at 118 AM CDT Thu Aug 14 2025

Main update early this morning was to increase the chance and
coverage of POPs across the James River Valley and along the
US/Canadian border. Nocturnal low level jet has resulted in
scattered thunderstorms across the eastern Dakotas the past few
hours, a few stronger storms along with locally heavy rainfall.
This activity should gradually move east through the next few
hours as the LLJ shifts farther east. Other modifications to the
forecast were minor.

UPDATE
Issued at 925 PM CDT Wed Aug 13 2025

Thunderstorm activity has trended down across the state with
some thunderstorms lingering across the border in South Dakota
and southeastern North Dakota. The 00Z sounding shows
significant capping hindering thunderstorm formation across
North Dakota this evening. Decreased the PoPs to match the
current trends.

UPDATE
Issued at 659 PM CDT Wed Aug 13 2025

Storms that started near an aforementioned dryline continue to
move through far southwest North Dakota, but so far the
strongest convection has held to our south over western South
Dakota. Expect this trend to continue per latest high-res
guidance, with maybe an isolated storm or two trying to perk up
briefly.

&&

.DISCUSSION...
Issued at 355 PM CDT Wed Aug 13 2025

Elevated warm front will bring increased instability through
this evening, although capping may also be found through the
evening. Although a thunderstorm may form anywhere along this
front through this evening, the better chances may initially be
in the southwest when a weak dry line in Montana moves through.
If this dry line can continue to push eastward, it will find
more increased dewpoints in the southcentral, possibly
continuing the chances for stronger thunderstorms. With adequate
cape and shear, hail to the size of a quarter and wind gusts to
60 mph. This again is all dependent on the cap breaking, which
is quite stout. SPC has maintained a general risk for
thunderstorms in the area, with the better chance for severe
weather still in South Dakota. Otherwise look for some breezy
southerly winds becoming lighter tonight. Any areas of smoke in
the north central should also diminish tonight. With increased
dewpoint, RH values will be high tonight. Winds should stay
elevated, thus the threat for fog is low. A cold front is still
expected to push across the state on Thursday from west to east.
Ahead of this front will be highs in the 90s and increasing
dewpoints perhaps into the upper 60s to lower 70s. As a result
the Heat Risk is now moderate, although high temperatures may
not quite be warm enough to reach heat advisory criteria.
Chances for severe weather remain across the eastern half of the
state for Thursday. Large amounts of cape and adequate shear
will remain. There still remains capping concerns and
uncertainty of the fronts timing. If storms can develop, main
threat looks to be large hail initially with any isolated
supercells, transition to a wind threat along the cold front.
Maintained hail to the size of a golf ball, although the
ingredients are there for hail to 2 inches or greater. Winds to
70 mph are also the main hazard, although there could be some
stronger gusts. Hodographs still show a low tornado threat,
although perhaps an isolated tornado is possible in eastern ND.
SPC has maintained a Marginal to Slight Risk in eastern areas.
Isolated thunderstorms could linger across the south Thursday
night, although the severe weather threat should diminish after
frontal passage. Lows will be cooler in the north in the 50s, to
the 60s south.

Front stalls out on Friday with a surface high across the north.
Cooler temperatures and northeasterly winds are expected as a
result. There could be some thunderstorm activity along the
stalled front in the south, although the threat for severe
weather is low. The northeasterly flow could also return some
wildfire smoke on Friday. High pressure aloft to our south
could bring southwesterly flow on Saturday providing for
slightly warmer temperatures. A ridge rider wave could also
return the chances for showers and thunderstorms, and perhaps
localized heavy rain given increased pwats. An isolated strong
to severe thunderstorm is also possible. This pattern of weak
disturbances moving over the high pressure could then linger
through the weekend into early next week. Temperatures remain in
the 80s for highs and 60s for lows. Near daily chances of
showers and thunderstorms could also be found. CSU-MLP currently has
low chances for severe weather during this time period.
Lingering high pwats could also promote localized heavy rain
with any thunderstorm activity.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 118 AM CDT Thu Aug 14 2025

Isolated thunderstorms remain possible tonight over eastern
areas of North Dakota and far north along the Canadian border.
Low VFR/MVFR ceilings are also expected early this morning
across the east, and will mainly be over KJMS this morning. During
the day on Thursday, isolated to scattered thunderstorms are
possible in the afternoon over central North Dakota and over
eastern North Dakota later in the afternoon and evening.

&&

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

&&

$$

UPDATE...NH
DISCUSSION...Anglin
AVIATION...NH