134
FXUS63 KBIS 161934
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
234 PM CDT Mon Sep 16 2024

.KEY MESSAGES...

- Thunderstorm chances continue through tonight, with an
  isolated to scattered severe thunderstorms possible, along
  with very heavy rain.

- An active pattern continues through the week, with strong to
  severe storms again possible Tuesday night.

- Temperatures will trend cooler through the week, after
  Tuesday, with forecast highs in the 60s to lower 70s by next
  weekend.

&&

.DISCUSSION...
Issued at 230 PM CDT Mon Sep 16 2024

Currently, large cutoff upper level low pressure centered over
central California, with a broad southwest flow aloft pattern
over the Dakotas. Well defined embedded wave continues to lift
northeast across the region (now over mainly northeastern ND),
along with all associated showers and thunderstorms north of
I-94 and mainly across northern areas of the state.

We remain fairly unstable this afternoon, with Mixed Layer CAPE
near 2500 and MUCAPE up to 3000, especially for those areas
that cleared this afternoon across much of the south. 0-6km wind
shear is modest, around 30-40 knots. CAMs have been consistent
(as the midnight shift last night pointed out) of most if not
all convective activity across north central into the Turtle
Mountains later today into the evening, along with some members
showing signs of activity in the James River Valley. This is
where the Slight Risk is maintained by SPC. Still, with the
amount of unstable air, the amount of moisture, and the
potential forcing with any subtle mid level wave lifting
through, will keep at least a slight chance of thunderstorms all
areas through this evening.

S/WV ridge momentarily builds over the Northern Plains later
tonight through most of Tuesday, as the aforementioned upper low
starts to meander east-northeast into the Intermountain West.
This will result in a warm and dry day for tomorrow, along with
ample sunshine.

Later on Tuesday and into Tuesday night, a warm frontal boundary
will be lifting north across the region, as the upper low swings
northeast into the Northern High Plains of eastern Wyoming and
Montana. This will result in another round of showers and
thunderstorms (some strong to severe) across the region during
this timeframe.

We will remain in an active upper level pattern through the work
week, with multiple periods of showers and potential
thunderstorms. There is also a very favorable probability for
temperatures trending cooler, with highs in the 60s to lower 70s
by next weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1244 PM CDT Mon Sep 16 2024

Chances for showers and thunderstorms will continue across
central North Dakota through much of the day while slowly
drifting north and eastward. Overall, VFR conditions are likely
to prevail, though some lower ceilings cannot be ruled out in
and around areas of showers and storms. Easterly winds around 5
to 10 kts will turn to the southeast and increase to 10 to 15
kts this afternoon, with some higher gusts possible, before
diminishing by early evening. Low IFR stratus will be possible
at KMOT later tonight, and possibly at KXWA. Low level wind
shear is also forecast for late tonight for KJMS.

&&

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

&&

$$

DISCUSSION...NH
AVIATION...NH