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000
FXUS63 KBIS 271916
AFDBIS

AREA FORECAST DISCUSSION
National Weather Service Bismarck ND
216 PM CDT Sat May 27 2023

.SHORT TERM...(This Evening through Sunday night)
Issued at 216 PM CDT Sat May 27 2023

An active period of weather continues through the short term as
blocking high pressure remains over the Great Lakes region, and a
west CONUS trough persists. As Gulf moisture continues flowing
into the western North Dakota, models suggest plenty of
instability will be present late this afternoon and evening in the
west. Up to 2000 J/kg of MLCAPE will be available along with 30
to even 40 kts of 0 to 6 km bulk shear. The question, however, is
whether or not there will be enough forcing to take advantage of
these otherwise favorable severe weather conditions. The next
shortwave doesn`t really look to come through until Sunday, while
the quasi-stationary surface frontal boundary looks likely to
wobble into southern Canada and northeastern Montana. The LLJ does
appear to ramp up after midnight, but the nose appears to be more
along the Canadian border, if not in southern Canada.

All that said, forecast soundings suggest the cap in western ND
isn`t that stout and will likely break by mid-afternoon. Thus,
it`s entirely possible that daytime heating alone will be enough
to fire off thunderstorms. It looks like then, at this point in
time, the best chance for severe weather is late this afternoon
and into the early evening before storms weaken as instability
diminishes and the best forcing is lost. Expect scattered strong
to severe thunderstorms with initial cells potentially producing
hail up to the size of golf balls. The window for that large of
hail will likely be narrow before storms cluster and quarter size
hail becomes the biggest threat.

For Sunday, instability doesn`t look quite as impressive, although
varies a lot model to model. Just as importantly, co-located
shear looks to return to weaker levels similar to prior systems the
past few days with maximum 0 to 6 km bulk shear closer to the 20
to 25 kt range. Showers and thunderstorms will probably initiate a
little earlier than this afternoon as well as shortwave energy
begins passing through the Dakotas by mid-afternoon. However, they
should once again diminish quickly as the sun sets. Isolated,
pulsey severe thunderstorms are possible with quarter size hail
being the biggest threat.

Expect highs to generally range in the upper 70s to low 80s this
afternoon and Sunday. Lows tonight will mainly drop into the 50s,
although some locations may remain in the low 60s. These values
are approximately 10 degrees above average for this time of the
year.

.LONG TERM...(Monday through Saturday)
Issued at 216 PM CDT Sat May 27 2023

The extended period is essentially more of the same with blocking
high pressure over the east CONUS keeping the west CONUS trough in
place. There will be some wobbles through the week. For example,
surface high over the Great Lakes region will meander a bit to
the northeast through mid-week. This will keep the Gulf open, but
result in moist air penetrating further east and also shifting any
severe weather potential further east as well. Monday, illustrates
this well with a marginal severe risk over the eastern two thirds
or so of the state. By the end of the week, however, high
pressure may wobble back towards the Great Lakes region
potentially shifting any severe weather threat a bit further west
and potentially centering over the entire state.

With shower and severe thunderstorm activity possible throughout
the short term, won`t dig too deep into any long range parameters
at this time. However, a very quick glance doesn`t contain any
days with eye popping shear. Should that remain the case, periodic
severe weather may be possible, but will be more limited in
nature.

Temperatures also remain more of the same through the extended.
Highs generally look to be in the 80s, with some locations
occasionally only reaching the upper 70s (namely the west on
Monday). Lows appear to consistently remain in the 50s to low 60s
as well. Similarly to the short term period, these temperatures
are generally around 10 to 15 degrees above average for this time
of the year.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1252 PM CDT Sat May 27 2023

Shower and thunderstorms should begin to develop mid and more so
towards late this afternoon. The terminals most likely impacted
will be KXWA and especially KDIK, however, thunderstorms may also
impact KMOT and KBIS this evening. Shower and thunderstorm
activity should remain west of KJMS. Most activity should end
shortly after midnight. Additional showers and thunderstorms are
not expected to develop through the remainder of the TAF period,
but are likely to develop within a few hours after 18Z Sunday. And
although VFR ceilings and visibility are expected to prevail,
reductions to both are always possible during any shower and
thunderstorm activity.


&&

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

$$

SHORT TERM...Telken
LONG TERM...Telken
AVIATION...Telken