513
FXUS63 KBIS 102151
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
451 PM CDT Mon Jun 10 2024

.KEY MESSAGES...

- Showers and thunderstorms will continue to expand eastward
  through the day today before ending from west to east this
  evening through tonight. Isolated strong thunderstorms are
  possible across south central North Dakota through this
  afternoon.

- Near average temperatures expected today and Tuesday. Highs on
  Wednesday will reach a crescendo with most locations reaching
  the 80s. 90 degree readings are possible in the southern James
  River Valley of North Dakota.

- A 20 to 40 percent chance of showers returns Wednesday
  evening. Higher precipitation chances are then forecast
  Friday night through the weekend.

&&

.UPDATE...
Issued at 449 PM CDT Mon Jun 10 2024

Allowed the Severe Thunderstorm Watch to expire. Storms are
moving into a much less favorable environment as they move
east, with instability expected to greatly diminish elsewhere
southwest with time now through early this evening. ALl products
have been updates.

&&

.DISCUSSION...
Issued at 229 PM CDT Mon Jun 10 2024

The bottom line up front is that a Severe Thunderstorm Watch has
been issued for Bowman and Adams County until 9 pm MDT. As such,
the main forecast challenge for today is the potential for
severe weather this afternoon and early evening especially for
far southwestern ND.

Presently, an embedded surface low circulation is located in eastern
Montana into northeastern Wyoming within an area of elongated
low pressure from Alberta, through eastern Montana, and into
western South Dakota. Aloft, a shortwave sliding through the
Dakotas is resulting in continued WAA across the forecast area
this afternoon, which should be the primary forcing mechanism
for continued showers and thunderstorms.

The aforementioned surface low pressure circulation will drift east
northeast through North Dakota today. Associated warm frontal
boundary on a north to south axis, along with trailing cold
frontal boundary, will slide across South Dakota. As a result,
the front northern extent will quickly become occluded. Factors
that favor severe weather in the southwest are that the RAP
suggests a narrow swath of 1500 J/kg of MUCAPE in the southwest,
along with adequate shear of 30 to 35 kts of 0 to 6 km bulk
shear. In addition, DCAPE values are generally not impressive,
but a narrow ribbon in excess of 900 J/kg is possible as well in
the far southwest. Besides the southwest, the RAP also suggests
up to 1000 J/kg of MUCAPE in the west central and northwest.
However, with excess cloud cover present and having been so all
day, along with morning and early afternoon showers and
thunderstorms working the atmosphere, sufficient instability
may be hard to find in the west central and northwest. Therefore
the severe weather threat seems very low in all but the far
southwest.

Any severe weather threat should end by late evening. At that
point, showers, along with a few thunderstorms, will end from
west to east. Skies will also clear out and Tuesday will feature
a mostly sunny and dry day with highs in the 70s to low 80s.
Other than a 20 to 40 percent chance of showers in the far south
Wednesday evening through Wednesday night, mostly dry
conditions are expected through the remainder of the workweek.
More widespread precipitation chances then return to the area
Friday night, through the weekend, and into next week. Models
are not in full agreement as to how this will play out, but the
potential exists for southwesterly flow aloft as strong upper
low pressure slides through southern Canada, potentially with
troughing into the southwestern CONUS.

Overall, expect temperatures to gradually increase before
reaching a crescendo on Wednesday with highs in the upper 70s to
upper 80s (possibly with a few 90 degree readings). Temperatures
will then become seasonable again for the latter half of the
week. Lows in the 50s will prevail through the period, though
occasional drops into the 40s or remnants in the low 60s are
possible various nights.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 106 PM CDT Mon Jun 10 2024

Widespread showers are occurring in much of western and north
central ND. These will continue moving/expanding eastward
through the day. Presently, most of the instability has been
lost and therefore lightning strikes are now few and far in
between. However, anywhere showers are present, there is a
greater than 25 percent chance of seeing lighting within the
next hour. Therefore, vicinity thunderstorms with occasional
thunderstorms are mentioned at most terminals. Another line of
showers and thunderstorms is expected to develop west of any
ongoing showers this afternoon. These storms have the potential
to become strong to severe this afternoon through the early
evening. While VFR ceilings and visibility are generally
expected to prevail most of the time, conditions will
deteriorate during any showers and thunderstorms. This includes
lowered ceilings, reduced visibility, and erratic winds.

&&

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

&&

$$

UPDATE...NH
DISCUSSION...Telken
AVIATION...Telken