282
FXUS63 KBIS 161931
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
231 PM CDT Thu Jul 16 2026

.KEY MESSAGES...

- One more day of very hot conditions across southern North
  Dakota, with heat index values and temperatures around 95 to
  100 this afternoon.

- Low chances (10 to 30 percent) for isolated thunderstorms from
  south central North Dakota to the Turtle Mountains late this
  afternoon and evening. A strong to severe storm or two are
  possible.

- Patchy fog is possible in northwest North Dakota tonight
  through mid Friday morning.

- Slightly cooler Friday and Saturday, then hot again for most
  areas on Sunday. Temperatures are then favored to fall closer
  to normal next week, with forecast highs mostly in the 80s.

&&

.DISCUSSION...
Issued at 230 PM CDT Thu Jul 16 2026

Increasingly zonal flow is found over the northern Plains this
afternoon as low amplitude shortwave moving across Canada
flattens the upper level ridge that has been prevalent over much
of the CONUS over the past week. At the surface, a center of
low pressure has been steady lofted toward northeast North
Dakota by the passage of the previously mentioned shortwave,
dragging an inverted surface trough / cold front across the
forecast area this afternoon. An interrogating of BUFKIT model
soundings across portions of central North Dakota reveals a
somewhat robust convective environment developing through the
early evening, with model MUCAPE values approaching 3000 to 3500
J/KG overlapping with 0-6KM shear values around 30 to 35 knots
over portions of the north central and the north east. The
biggest obstacle to CI would be a fairly robust low level
capping inversion over much of the forecast area, with 850mb
temps roughly 5 degrees higher than the surface. That being
said, with forecast surface temperatures expected to approach
convective temperatures by the early evening, it wouldn`t be
overly surprising to see this cap erode enough to allow for some
isolated thunderstorms to develop. With orientation of BULK
shear vectors generally perpendicular to the inverted
trough/cold front, discrete storms can generally be
anticipated, while sufficient shear and with at least somewhat
curved hodographs could promote a transient supercell or two.
The primary hazard associated with any severe storm would be
large hail up to 2 inches in diameter, though high DCAPE values
approaching 1500 J/KG would also suggest strong winds up to 70
MPH are also possible. The overall potential for tornadoes
remains low, with near surface SRH and shear values remain well
below expected norms. That being said, conditions across north
central North Dakota are analogous to previous events where
we`ve had had high-based hybrid tornadoes, where a developing
landspout along a surface boundary becomes anchored to a
supercell (with research suggesting these types of hybrid
tornadoes occur when you have an overlap of very high cape
values exceeding 3000 J/KG, strong deep layer sheer around 30 to
40 knots, low near surface SRH, and developing supercells along
a cold front). With that in mind, we will need to keep a close
eye on any supercells that do end up developing this evening.
Also of note is the above normal PWATs over much of central and
eastern North Dakota today, around 1.5 to 1.75 inches, which
means that heavy rainfall can also be anticipated with any storm
that does develop. With a discrete storm mode, this heavy
rainfall is expected to be fairly brief, and thus flash flood
concerns remains low at this time. For today, the SPC has placed
portions of north central North Dakota and the northern James
River Valley into a Marginal (level 1 of 5) risk for isolated
severe thunderstorms.

Above normal high temperatures in the mid 90s to lower 100s
continue along the south half of the state today, while
conditions across the normal remain slightly cooler with highs
from the lower 80s to lower 90s. Along with dewpoints generally
in the upper 60s to lower 70s, apparent temperatures across
portions of the southwest and south central are expected to be
around 100F this afternoon into early this evening. A Heat
Advisory remains in effect along and south of Highway 200
through 10 PM CDT tonight. With low temperatures forecast mainly
in the lower 60s to lower 70s, better overnight recovery is
expected across western and central North Dakota than we have
seen all week, which is help alleviate further heat concerns
moving into the start of the weekend. Otherwise for tonight,
patchy fog will be possible across portions of the far northwest
through Friday morning as a near surface temperature inversion
develops, and as northeasterly winds become very light
overnight.

Northwesterly flow is then generally expected across western
and central North Dakota as we head into the weekend, promoting
a slight cooling trend that will promote highs from the lower to
mid 80s along the International Border, up to the mid 90s and
lower 100s. This synoptic pattern is also more conducive for
precipitation, with at least low chances for showers and a few
storms expected late Friday into Saturday morning across the far
west. A more robust Canadian trough is then expected Saturday
night into Sunday, turning flow aloft more zonal and promoting
low to medium chances for precpitation across much of western
and central North Dakota. Overall QPF is expected to be fairly
limited due to the transient nature of these showers and storms,
though high PWATs through the weekend would allow for brief
period of moderate to heavy rainfall when and where
thunderstorms develop. CSU machine learning has begun to
highlight portions of the forecast on Sunday, which is expected
to be associated with storms in the afternoon. We will monitor
forecast trends through the weekend.

A return to northwesterly flow as we head into early next week
will again allow the cooling trend to continue, bringing highs
back down toward near normal by the midweek. With this synoptic
pattern, low chances for showers and thunderstorms can be
expected somewhere in North Dakota just about any given day,
though the ensemble does not advertise a strong precpitation or
severe signal at this time.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 230 PM CDT Thu Jul 16 2026

VFR ceilings and visibility found at most terminals to begin the
18Z TAF period. MVFR ceilings are expected to linger at KXWA
over the next few hours, but will improve to VFR heights by the
mid afternoon. Late this afternoon into the this evening,
isolated showers and thunderstorms may develop across portions
of central North Dakota. Predictability in timing and location
is low at the time of this update. Where thunderstorms do
develop, expect gusty and erratic winds. Tonight into Friday
morning, low MVFR to IFR ceilings are expected to develop across
portions of the area, including the terminals of KMOT, KDIK,
and KJMS. IFR to LIFR ceilings and patchy fog is possible at
KXWA overnight through mid Friday morning. Low stratus and fog
is expected to lift by the mid to late Friday morning, leaving
VFR ceilings and visibility at all terminals through the end of
the TAF period. Light winds at the start of the TAF period are
expected to strengthen and organize out of the north to
northwest as an inverted surface trough lifts across the
forecast area, before again weakening and becoming variable
this evening. Winds are then expected to reorganize out of the
north and strengthen Friday morning and afternoon.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Heat Advisory until 10 PM CDT /9 PM MDT/ this evening for
NDZ017>020-022-023-025-031>033-035>037-040>044-046>048-050-051-
057>062.

&&

$$

DISCUSSION...Adam
AVIATION...Adam