FXUS63 KBIS 312050
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
350 PM CDT Sun May 31 2026

.KEY MESSAGES...

- Marginal Risk (level 1 out of 5) severe weather through this
  evening over much of south central North Dakota.

- Marginal (level 1 out of 5) to Slight Risk (level 2 out of 5)
  of severe weather on Tuesday.

- Low to medium chances of showers and thunderstorms Wednesday
  through the remainder of the week.

&&

.DISCUSSION...
Issued at 350 PM CDT Sun May 31 2026

Surface low will retreat into southern Canada tonight, pushing a
cold front across the state from west to east this evening
through tonight. Isolated to scattered thunderstorms are
expected as this front moves through. SPC has maintained a
Marginal Risk for severe weather in south central North Dakota.
This area has modest CAPE 1000 to 2000 J/Kg with ample heating
and increased dewpoints in the 60s today. Shear is lacking
today, with effective shear 25 to 30 knots. Shear vector is
angled to the front indicating multicluster storms the likely
storm mode today. Mid level lapse rates also look lacking today,
although steep lapse rates are found in the lower levels. Given
modest CAPE and some shear, pulse multi cell storms could bring
winds gusts up to 60 MPH winds and hail up to quarter size
through this evening. With steep low level lapse rates and
increased CAPE in these lower levels, perhaps a non-supercell
funnel cloud is possible through this evening. The lack of low
level shear should limit this threat. Otherwise look for a
breezy southeast wind to become a breezy westerly wind during
front passage. Precipitation will push eastward through the
night. Cooler temperatures will move in behind this front
tonight with lows in the 40s west to lower 50s east. A cooler
post frontal day is then expected for Monday. Look for breezy
westerly winds through the day, especially in the northwest.
Precipitation chances should be minimal with perhaps some light
chances in the north along the stalled front. Look for highs in
the 60s northwest to near 80 southeast. Upper upper low stalled
in Canada approaches western ND Monday night. This could return
chances for showers and thunderstorms in the west. Lows will
remain cool in the 40s to lower 50s.

Upper low remains in the area for Tuesday and Wednesday. Warming
temperatures and increase moisture from a southerly flow will
bring modest instability to the area. Shear will also be
increased from the upper level low aloft. The result could be
one to two days of severe weather across the state. Tuesday
currently has a Marginal to Slight Risk across much of the
state. Strong wind and large hail are the likely main threats
for Tuesday. A shear vector angled to parallel to the frontal
boundary could limit the discrete supercell potential and the
stronger hazards associated with that. Although that could
change given this setup is still a few days out. The increased
amounts of instability with this system could also provide for a
prolonged severe weather threat, with some CAMS starting
convection late morning and continuing through the evening.
Increased Pwats over an inch are also forecast for Tuesday.
With near saturated soils this could lead to some localized
flooding especially in central and eastern portions. WPC
currently has a marginal risk for excessive rain. Similar
conditions may be found on Wednesday although severe weather and
heavy rain threat may shift eastward with the upper low
shifting eastward. Lows through mid week will remain in the
upper 40s to upper 50s, while high in the 70s to lower 80s can
be expected.

Zonal flow aloft could continue the summer like pattern for
late in the week as temperatures remain above normal. This
combined with weak disturbances in the westerly flow could bring
daily chances for showers and thunderstorms. CSU-MLP showing
limited threat for severe weather, with perhaps some isolated
activity possible during the upcoming weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1245 PM CDT Sun May 31 2026

Partly to mostly cloudy skies today will bring low VFR to MVFR
ceilings. Chances for showers and thunderstorms will increase
this afternoon through this evening, further spreading MVFR
conditions and perhaps some brief IFR ceilings. Most sites have
PROB30 mention for thunderstorms with some higher confidence
sites having prevailing lines for showers. MVFR to perhaps some
IFR ceilings could then linger tonight, with chances for showers
and thunderstorms diminishing from west to east. Generally VFR
conditions are then expected for Monday. Breezy southerly wind
today will become a breezy westerly wind tomorrow, continuing
into Monday.

&&

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

&&

$$

DISCUSSION...Anglin
AVIATION...Anglin