469
FXUS63 KBIS 301930
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
230 PM CDT Thu Jul 30 2026

.KEY MESSAGES...

- Medium to high chances (40 to 70 percent) for showers and
  thunderstorms across the southern two thirds of North Dakota
  today. A few storms could be severe and produce locally heavy
  rainfall.

- Cooler but humid today, then becoming very hot again over the
  weekend.

- Hot, dry, and windy conditions on Sunday could result in at
  least near-critical fire weather conditions across much of
  the western half of the state.

&&

.DISCUSSION...
Issued at 230 PM CDT Thu Jul 30 2026

Southwesterly flow is found over the northern Plains this
afternoon as a shortwave traverses the upper level ridge exiting
the region to the east. With the passage of this shortwave,
showers and thunderstorms have developed across much of western
and central North Dakota today, mostly along the associated
surface cold front slowly making its way southeast across the
forecast area. With the greater access to the Gulf moisture
plume that this pattern allows, dewpoints are expected to rise
well into the mid 60s to mid 70s this afternoon, highest across
the south central. With this contributing to model MUCAPE values
peaking well into the 1500 to 2500 J/KG range, and with the
broad synoptic lift accentuated by 850mb jet dynamics late this
afternoon and evening, at least a few stronger to marginally
severe thunderstorms will be possible today, though they will
need to overcome a weak 850-900mb CAP. The overall lack of shear
across the area, with model 0-6KM values peaking only around 15
to 25 knots, is expected to keep any stronger storms fairly
transient. As of the latest forecast cycles, short term CAMs
dial into the stronger storm potential over the southwest late
this afternoon, where the influence of the mid level jet is
expected to be greatest, and where a weak surface low anchored
to the cold front is expected to cut across before moving into
South Dakota. Of note today is the potential for landspouts to
develop along the slow moving cold front, with global models
advertising enhanced surface vorticity along this boundary in
the mid afternoon through the early evening. The area to watch
would be over south central into southeastern North Dakota,
including the James River Valley, where this surface vorticity
is both maximized and potentially further enhanced by subsequent
outflow boundary interactions from decaying storms earlier in
the day. SPC has placed much of the forecast area along and
south of Highway 200 into a Marginal (level 1 of 5) Risk for
isolated severe thunderstorms this afternoon. Regarding
potential hazards we will continue to advertise large hail up to
the size of quarters, and wind gusts up to 60 MPH, while also
mentioning the expectation for locally heavy rainfall where and
when thunderstorms develop. High PWATs in the 1.5 to 2.0
range and warm rain processes have already contributed to
rainfall totals of 1.5 to 2.5 inches across portions of the
northern James River Valley this morning, where storms were
fairly short lived. The developing storms this afternoon have
been fairly stationary so far, which means this heavy rainfall
may linger over an area for a while. We will need to monitor for
potential flooding through this afternoon and evening, though
CAMs continue to advertise the gradual acceleration of this
system out of the forecast area through the late afternoon and
evening.

Otherwise, the main story through the remainder of the week is
going to be the return of warmer temperatures and drier
conditions as a transient upper level ridge slides across the
northern Plains. While lingering zonal flow and a weak shortwave
could promote some scattered storms will be possible over the
northwest on Friday, the shift toward northwesterly flow will
preclude any notable precipitation through the weekend. Highs
each day are expected to increase, from being broadly in the 80s
this afternoon, into the 80s and 90s on Friday, and back into
the 90s and 100s Saturday and Sunday. Despite the lower
dewpoints expected across the forecast area this weekend, some
consideration for potential heat headlines must be given over
the next few forecast cycles, especially as the contribution of
short-term CAMs to the ensemble increases, and as the potential
for compressive heating ahead of a weak cold front late Saturday
through Sunday may drive temperatures across portions of the
south central evening well into the upper end of the model
spread.

Of note during this period is the potential for near critical
to critical fire weather conditions across portions of western
North Dakota starting Sunday. The passage of the aforementioned
weak cold front Saturday night through Sunday, then the passage
of a stronger cold front Sunday through Monday, is expected to
promote breezy winds in the afternoon and evening hours. With
mostly prevailing dry conditions expected through this period,
though the passage of the stronger cold front Sunday through
Monday may promote at least low chances for showers and storms
across much of western and central North Dakota, and with fuels
across much of western and especially south central North Dakota
having started to cure over the past few weeks, we will need to
monitor trends over the next few days due to fire weather
concerns.

Looking further ahead, the ensemble advertises cyclonic flow
aloft as a low pressure system slowly meanders across northern
Canada. With this pattern, somewhat cooler weather mainly in the
70s and 80s can be anticipated, with some off and on chances
for precpitation through the mid week. Beyond this period, the
ensemble becomes split between a warmer and drier scenario (55
percent membership) as the upper low is dislodged further to the
east and a transient upper level ridge slides across the
region, and a continuation of the cooler and comparably wetter
conditions (45 percent membership) as the upper level low
retrogrades in place through the end of the workweek.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 230 PM CDT Thu Jul 30 2026

VFR ceilings and visibility are found at all terminals to begin
the 18Z TAF period. Showers and thunderstorms have begun to
develop this afternoon, and are expected to move across most of
southwestern and central North Dakota through the early to mid
evening. Where thunderstorms develop within the broader
precpitation shield remains fairly uncertain, thus have opted to
utilize PROB30 groups for -TSRA at most terminals through this
period, with the exception of KXWA where no showers and storms
are currently anticipated. Where thunderstorms do develop, gusty
and erratic winds should be anticipated. In the south central,
where showers and storms are expected to be most persistant, low
VFR to high MVFR ceilings are possible later this evening into
the early overnight period. Light winds turning cyclonically
around a low pressure center far to our south are expected to
further weaken this evening and overnight, becoming variable in
direction until strengthening and turning anticyclonically
around a high pressure center moving in across the International
Border Friday morning and afternoon.

&&

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

&&

$$

DISCUSSION...Adam
AVIATION...Adam