657
FXUS63 KBIS 300006
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
706 PM CDT Sun Jun 29 2025

.KEY MESSAGES...

- Breezy through Monday, with slightly cooler temperatures and
  lower humidity.

- Other than a 20 percent chance of showers and perhaps a
  thunderstorm in northern parts of the state late this
  afternoon and this evening, dry weather is expected through
  Tuesday afternoon.

- Above normal temperatures are favored Wednesday and Thursday,
  with highs possibly reaching 90 degrees.

- Low chances for showers and thunderstorms during the evening
  and overnight hours Tuesday and Wednesday, then medium
  chances late Thursday. Widespread severe storms are not
  expected at this time.

&&

.UPDATE...
Issued at 640 PM CDT Sun Jun 29 2025

We made some minor adjustments to pops, extending them down a
little farther south over the northern CWA. We had some gusts to
40-45 mph early on after this shower activity developed, but
coverage has backed off and gusts haven`t been as high. Also
added some slight chance for thunderstorms over the far south
central into the James River Valley, in an area of modest CAPE
and effective shear. Updated text products will be transmitted
shortly.

&&

.DISCUSSION...
Issued at 229 PM CDT Sun Jun 29 2025

Latest satellite imagery shows a broad cyclonic upper level flow
from the southern Canadian Prairie Provinces, into the Northern
High Plains with a number of impulses tracking through the
general upper level flow. At the surface, low pressure extended
from the northern Great Lakes into the Central Plains, with high
pressure over the Northern Rockies.

For tonight, surface high pressure will track east from the
Northern Rockies, into the Northern Plains. An impulse moving
through the Northern Rockies has sparked convection for
southeast Montana, south to the Black Hills. This thunderstorm
activity is moving pretty much due east, and should remain
south of the state line, in South Dakota. Additional impulses
were located from southeast Saskatchewan into eastern Montana.
These impulses have produced isolated showers from northeast
Montana, east into far north central ND. This shower activity
will persist over the northern tier counties of western and
central ND into this evening. The overall general cyclonic flow
from southern Canada will drop southeast overnight, pulling
more widespread cloudiness from southern Canada, at least into
the northern and eastern portions of the forecast area. A decent
surface pressure gradient should also help keep it on the
breezy side overnight.

On Monday, the Canadian shortwave trough drops southeast into
the Upper Great Lakes region. This could keep a chance of shower
activity in the far eastern portions of central ND, but most
activity should remain over eastern ND and into northwest
Minnesota. A stray shower or two can not be ruled out though
from the Turtle Mountains into the James River Valley. It will
be breezy again Monday, moreso over central ND, compared to the
west. In general, temperatures will be similar to today, but a
little cooler southeast and a bit warm north and west.

We remain within a northwest upper flow pattern Tuesday and
Wednesday with increasing temperatures each day. By Wednesday we
should be well into the 80s most areas, with some 90 degree
readings possible in the west. Impulses propagating through the
northwest upper flow will provide small chances (20 percent) for
showers and thunderstorms.

On Thursday we shift from a northwest to a southwest upper level
flow with a building thermal ridge and a noticeable increase in
moisture. Although there is not a distinct signal for severe
weather, the increasing instability should yield at least some
chances for thunderstorms as we head into the Independence day
Holiday. The CSU machine learning page is hinting at low
probabilities for severe storms on both the 3rd and 4th of
July. The envelope of ensemble solutions remains broad at this
time but NBM ensemble Pops have increased to widespread chance
and even some likely Pops Thursday night through Friday night.
We`ll see how things evolve as we move through the upcoming
short work week.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 640 PM CDT Sun Jun 29 2025

VFR conditions are expected through the 00Z TAF period. Shower
activity, too isolated in nature to include in any one TAF will
diminish this evening. Showers may linger along the
International border north of KMOT through the evening, but
should generally stay north of KMOT. Winds will diminish later
this evening, but may remain a little breezy at times
overnight, especially at higher elevations. Winds will pick up
again mid to late morning on Tuesday from the west to northwest.
MVFR ceilings dropping south from Canada may clip eastern
portions of the forecast area for a brief period Monday morning,
including KJMS, but uncertainty too high to mention attim.

&&

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

&&

$$

UPDATE...TWH
DISCUSSION...TWH
AVIATION...TWH