243
FXUS63 KBIS 151801
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
101 PM CDT Tue Jul 15 2025

.KEY MESSAGES...

- Medium to high chances for showers and storms will continue
  through late Wednesday.

- Well below normal temperatures Tuesday through Thursday, with
  near-record cold highs in the 60s Tuesday and Wednesday.

- Dry Thursday, then more chances for showers and storms through
  the end of the week.

&&

.UPDATE...
Issued at 100 PM CDT Tue Jul 15 2025

With the high pressure moving into northern North Dakota, the
showers are mainly just along and south of the Interstate. More
showers in a few hours will move into the southwest from Montana
ahead of another shortwave.

UPDATE
Issued at 945 AM CDT Tue Jul 15 2025

Widespread showers continue across the southwest and central
parts of North Dakota. The thunder chances have now diminished
to mainly south of the Interstate through the rest of the day.
Updated the PoP forecast, and the latest observations have been
blended in.

UPDATE
Issued at 650 AM CDT Tue Jul 15 2025

Widespread showers and a few rumbles of thunder are found across
northwestern and north central North Dakota this morning.
Further south, more isolated to scattered showers can instead be
found. Showers are anticipated to generally build in across the
south through the late morning and early afternoon period.
Otherwise this morning, temperatures are generally from the
upper 50s north to the mid to upper 60s south. Northwest winds
are breezy, with sustained speeds up to 15 MPH and gusts up to
25 MPH, though areas under the heaviest showers have been known
to gusts as high as 30-35 MPH. Have tweaked PoPs and cloud cover
with this update to account for the latest trends, but otherwise
the forecast remains on track.

&&

.DISCUSSION...
Issued at 400 AM CDT Tue Jul 15 2025

Near zonal flow is found aloft over the northern Plains this
morning, though is expected to become increasingly southwesterly
through the late morning and afternoon as a series of depending
shortwaves move eastward. A quasi-stational front lingers
across south central North Dakota this morning, promoting on-going
showers and a few thunderstorms across this area. This front is
expected to continue to be pushed further south through this
morning, potentially exiting to the south of the forecast area
as a cold front by the early afternoon. Showers and embedded
thunderstorms have also developed across much of northwestern
and north central North Dakota, with medium to high chances (45
to 85 percent) spreading widely across the forecast area through
the afternoon. Severe weather is generally not expected today,
though a stronger storm or two capable of producing small hail
is not impossible in the far southern James River Valley as the
aforementioned front exits to the south. On the backside of this
cold front temperatures today are much cooler than the day
before, with high temperatures forecast broadly in the 60s and
70s this afternoon. Moderate CAA across the forecast area and a
tight W-E orientated pressure gradient will help keep
northwesterly winds breezy through much of the day today, with
sustained gusts up to 20 MPH and gusts up to around 30 MPH.

With high pressure starting to build into the region out of the
southern Canadian Prairies this evening and overnight, chances
for showers and thunderstorms will start to diminish across
eastern and central North Dakota overnight into Wednesday.
Medium to high chances (40 to 70 percent) will linger across
western North Dakota as low pressure system associated with a
moderately upper level trough cuts across Wyoming and western
South Dakota. These chances are expected to expand to include
south central North Dakota as showers and storms develop along
an surface trough trailing behind the aforementioned low
pressure system. With the ongoing showers expected in the
southwest and the cooler airmass over the forecast area, high
temperatures on Wednesday are expected to be unseasonably
cooler, broadly in the 60s though portions of the southwest may
struggle to break through the upper 50s.

With high pressure settling over the northern Plains through
Wednesday afternoon, all showers and storms are expected to move
off to the south by late afternoon, early evening period. When
it`s all said and done, additional rainfall totals approaching
another 0.5 inch are possible, with the best chances (30 to 50
percent) found south of Highway 2. In the southwest, where
showers are expected to linger throughout the whole period,
there is a small chance that additional rainfall totals could
exceed 1 inch overall (~30 percent chance).

A transient upper level ridge17 is then expected to build in
behind the upper level trough on Thursday, helping keep
conditions dry across the forecast area and kick starting a
warming trend that will continue through the end of the week,
with highs broadly back into the 70s Thursday afternoon. A
return to near zonal flow is then favored by the ensemble,
sustaining the warming trend while reintroducing off and on
chances for showers and thunderstorms through the end of the
week. With another positively tilted upper level trough progged
to cut across the southern Canadian Prairies Thursday night
through Friday, medium to high chances (40 to 70 percent) for
showers and storms are expected. With this pattern, there is a
non-zero chance for some stronger to severe storms to develop,
though any details about potential timing and hazards is hazy
this far out. The CSU machine learning algorithm does paint a
low potential for severe weather across the southwest on
Wednesday. On the backside of this trough, generally zonal to
northwesterly flow is expected to develop as a transient upper
level ridge slides across the northern Plains, drying conditions
out somewhat for Saturday. The ensemble then diverges somewhat
at this point, with the majority of members (~80 percent)
favoring a much more quickly moving ridge, subjecting the
forecast the southwesterly flow Saturday night through Sunday,
and according an uptick in precipitation chances (30 to 50
percent) broadly across the area. CSU machine learning lightly
paint southwestern North Dakota again on Sunday with a low
potential for severe weather, which would be associated with
this pattern. This solution is the cooler of the two, with high
temperatures peaking into the 80s by Sunday. A minor cluster
also exists (~20 percent), which instead favors a much more
slowly moving upper level ridge, which would help limit PoP
chances on Sunday and the limit the potential for severe weather
even further. Additionally, this pattern would also promote the
warmest temperatures across the forecast area, with highs
peaking in the 90s. The ensemble gets increasing discordant
beyond this point, though a general agreement a slight cooling
trends through the early portions of next week is evident. The
CPC 6 to 10 day outlook reflects this, with near normal to
slightly below normal temperatures anticipated for July 20th
through the 24th.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 100 PM CDT Tue Jul 15 2025

IFR to VFR through tonight. Lower CIGs with the rain showers.
CIGs should lift from north to south. Breezy through most of the
period with northerly winds around 20kts. Winds will switch to
the northeast Wednesday afternoon. Rain showers will stay in
the south for the most part this afternoon and evening.


&&

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

&&

$$

UPDATE...Smith
DISCUSSION...Adam
AVIATION...Smith