Bismarck, North Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

574
FXUS63 KBIS 201437
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
937 AM CDT Sun Jul 20 2025

.KEY MESSAGES...

- Isolated to scattered severe thunderstorms are possible today
  through this evening. Expected hazards include hail up to 2
  inches in diameter, damaging wind gusts up to 60 mph, a
  tornado or two, and heavy rainfall.

- Isolated severe thunderstorms are possible Monday afternoon
  through Monday night and again Tuesday afternoon through
  Tuesday night. Main hazards will be large hail, damaging
  winds, heavy rainfall, and perhaps an isolated tornado.

- Daily chances for showers and thunderstorms continue through
  the upcoming work week.

- High temperatures will generally be in the mid 70s to lower
  80s through midweek, before warming up into the mid 80s to
  lower 90s later in the week.

&&

.UPDATE...
Issued at 923 AM CDT Sun Jul 20 2025

Area of showers and thunderstorms continues to develop east
across central North Dakota, with a few isolated showers
elsewhere. Stronger area of convection continues along the ND/SD
border in far south central ND, but has mainly stayed to our
south along with hail reports near the main core of the storm
pea size, with MRMS overestimating a bit. All activity is
associated with an embedded mid level wave passing east through
the region this morning, and should mostly exit to our east by
early this afternoon. POPs were modified based on latest radar
and trends.

Next round of storms comes this afternoon, though models are
once again not in agreement making for a tricky forecast.
Overall it looks like possible strong to severe convection
initiating somewhere over southwest or south central North
Dakota this afternoon, with another round of storms possible
later in the evening across the west from lingering Montana
convection. Will adjust POPs and messaging as needed today as
forecast confidence increases.

UPDATE
Issued at 640 AM CDT Sun Jul 20 2025

Wake low has dissipated across eastern portions of the CWA this
morning. A secondary round of showers and thunderstorms has
developed across the west and will continue to push eastward
this morning. Although instability has increased somewhat this
morning, it is still lacking for stronger storm development.
Perhaps some small hail and wind gusts to 50 MPH are possible
with storms this morning. Strong to severe storms are still
possible this afternoon and evening. Made some minor PoP updates
based on radar trends. Thunderstorms have also limited patchy
fog potential in the west. Any brief clearing through mid
morning could still bring some patchy fog, although confidence
is low in this occurring.

&&

.DISCUSSION...
Issued at 418 AM CDT Sun Jul 20 2025

A stalled boundary at the surface combined with a developing
surface low and an unsettled troughing pattern aloft will bring
chances for showers and thunderstorms throughout the day today
and into tonight. Currently, showers and thunderstorms are
moving across the north and south. Of note are strong non
thunderstorm winds associated with a wake low in the shower
activity currently in south central North Dakota. As this
feature moves eastward wind gusts of 50 to 60 mph may briefly be
found. Have issued an SPS to inform of this hazard and will
continue to monitor as it moves eastward. Some lower clouds in
the southwest may also develop patchy fog this morning, although
shower and thunderstorm in this area may limit this fog
potential. For the rest of today, this unsettled pattern could
bring chances for showers and thunderstorms throughout the day.
Later this afternoon through this evening, CAPE values increase
while shear remains high. Thus isolated to scattered severe
thunderstorms remain possible, with SPC continuing the Marginal
and Slight risk across the area. Shear vectors today may more
promote multicluster cells, with perhaps some discrete cells
possible. Given high shear and CAPE went with 2 inch hail as
the main threat. Limited DCAPE will keep the wind threat to
around 60 mph. High amounts of low level shear and increased low
level storm relative helicity indicate perhaps a tornado or two
is possible today. This would require thunderstorms to be more
discrete, which is an area of uncertainty today. Given this
possibility have included in storm messaging for today. Heavy
rainfall is also possible today with pwat values 1.5 to 2.0
inches. WPC has a Marginal and Slight risk for excessive
rainfall today through tonight to account for this potential.
Otherwise look for highs in the 70s to lower 80s today, with
some breezy winds in the east. Tonight will see continue chances
for showers and thunderstorms with perhaps an isolated severe
thunderstorm. If thunderstorms can diminish, patchy fog is
possible across much of the CWA. Lows tonight will be mild and
generally in the mid 50s to mid 60s. Widespread chances for
showers and thunderstorms looks to continue for Monday as the
mentioned boundary and surface low remains across the region.
Instability is not as high Monday, although shear remains high.
Shear vectors are more along the boundary, limiting the chances
for discrete cells. That being said, depending where the surface
low sets up there could be a tornado risk in addition to large
hail and damaging winds. This is again dependent on any
discrete storms forming, and increased storm relative helicity
from the surface low. High pwats will also keep heavy rainfall
as a concern for Monday, especially if any training storms can
develop. Highs will be slightly warmer on Monday, with
widespread 80s expected. Showers and thunderstorms look to
continue through Monday night with an upper wave moving through.
Perhaps an isolated severe thunderstorm is possible, with heavy
rainfall also possible. Lows Monday night will be in the mid
50s to mid 60s.

Unsettled pattern looks to continue for Tuesday with a broad
surface low in the area. Increased instability and shear also
look to remain. SPC has a Marginal Risk for severe weather now
on Tuesday, with large hail, damaging winds, and heavy rainfall
the main threats. Highs may be slightly cooler in the 70s across
north on Tuesday, with 80s lingering in the south. Showers and
thunderstorms may then linger through Tuesday night as a cold
front moves through. Isolated severe weather will again be
possible, with lows in the mid 50s to mid 60s. Broad trough
pattern looks to linger through the mid week time frame,
bringing near daily chances for showers and thunderstorms and
near normal temperatures. A transition to more zonal flow Friday
into the weekend looks to bring warmer temperatures, perhaps in
the 90s, yet continued chances for showers and thunderstorms.
CSU-MLP has limited severe weather threats Wednesday and
Thursday. It then shows the return of at least low chances for
severe weather Friday into the weekend.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 640 AM CDT Sun Jul 20 2025

Showers and thunderstorms will push eastward across the state
this morning, with perhaps more rounds of showers and
thunderstorms this afternoon through tonight. This could bring
some low VFR to MVFR conditions. Low clouds behind these storms
could also bring some MVFR to perhaps isolated IFR conditions
through today. Isolated to scattered shower and thunderstorm
chances could return this afternoon through tonight, perhaps
bringing MVFR to IFR conditions. Have added in some PROB30
groups to account for these chances. Low clouds and perhaps
some fog may return tonight, if thunderstorm activity can
diminish. Confidence was too low to include fog mention,
although have introduced some lower clouds. Southeasterly winds
will continue through the forecast period, and could be breezy
at times across the east.

&&

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

&&

$$

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