000
FXUS63 KBIS 282341
AFDBIS

AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
641 PM CDT Sun May 28 2023

.UPDATE...
Issued at 622 PM CDT Sun May 28 2023

South to north streamers of scattered to numerous showers and
thunderstorms continue across much of western and central North
Dakota. The most favorable area for a few strong storms will
generally be along and just east of the Highway 83 corridor. This
area is where instability is currently maximized given less cloud
cover earlier in the day. That being said, deep layer shear
remains weak (20 to 30 knots) so storms will struggle to organize.
Still, a few stronger cells could produce some small hail with
gusty winds in the 40 to 50 mph range. Locally heavy rain will
also continue to be a threat under any training storm segments,
but at least the system has moved a bit further east today, away
from the more saturated areas that saw quite a bit of rain the
past few days.

&&

.SHORT TERM...(This Evening through Monday)
Issued at 230 PM CDT Sun May 28 2023

Forecast highlights in the short term period will again focus on
the chance for thunderstorms and the possibility for locally
heavy rain along with a few stronger storms possible south
central.

Currently, S/WV mid level trough slowly lifting north across the
western Dakotas, with multiple embedded impulses also moving
through or projected to do so through tonight. Area of showers
across western ND pushing north, associated with one of these
waves. Thus far no lightning in North Dakota, but a few cells have
recently popped up over central South Dakota as another embedded
impulse approaches and thanks to daytime heating.

Still expecting a pretty decent coverage of showers and storms
over central and portions of western ND to develop over the next
few hours, lasting into the evening before eventually moving off
to the north/northeast later tonight. PWATs remain elevated so
locally heavy rain will again be possible with any stronger storm.
Flow aloft isn`t as weak, so storm movement should limit the heavy
rain/flooding threat to some degree. SPC did increase the coverage
of the Marginal outlook into south central ND, mainly for forcing
aloft and MUCAPE. Bulk shear is weak (20-30knots), so wouldn`t
expect much more than hail to quarters with any stronger updraft
that can form, which is possible with a few CAMs showing some
updraft helicity tracks over the south central late afternoon
through mid evening.

.LONG TERM...(Monday Night through Sunday)
Issued at 230 PM CDT Sun May 28 2023

An active southwest/southerly flow aloft pattern persists through
much of the long term period.

Upper level ridge/area of high pressure lingers off to our east,
while persistent troughiness remains to the west. Each day next
week will see chances for showers and storms, with specific timing
dependent on when any embedded wave passes through the region or
during peak heating if we lack an inversion. Temperatures will be
fairly consistent, with lows in the 50s/lower 60s and highs in the
mid/upper 70s into the 80s overall.

Models do indicate the upper level high retrograding back west
over the Great Plains late in the period, though flow aloft looks
week so would not expect any trend towards drier weather at this
time.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday Evening)
Issued at 622 PM CDT Sun May 28 2023

Scattered to numerous showers and thunderstorms continue across
much of western and central North Dakota. KMOT will likely be
impacted by some stronger thunderstorms in the vicinity over the
next hour or two. Weaker showers and storms will remain possible
over the northwest over the next couple hours as well, potentially
impacting KXWA. More development will be possible later this
evening and could track near KBIS but this activity is less
certain. Thus, will keep VCTS in the forecast for KBIS but will
hold off on any prevailing groups at this time for precipitation.
There could be brief visibility reductions to MVFR or IFR
categories with any stronger storms that move overhead. Winds may
also become gusty and erratic under or around any storms. With
the exception of conditions underneath thunderstorms, VFR
conditions are expected.

&&

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

$$

UPDATE...ZH
SHORT TERM...NH
LONG TERM...NH
AVIATION...ZH