756
FXUS63 KBIS 080606
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
106 AM CDT Sat Jun 8 2024

.KEY MESSAGES...

- Isolated showers (20 percent chance for rain) are forecast for
  Saturday. High temperatures to remain near to slightly below
  seasonable normals. There is a 30 percent chance of showers
  Sunday night.


- Widespread chances (20 to 50 percent) for showers and
  thunderstorms to be found Monday.

- Cooler temperatures expected Sunday and Monday. How much
  cooler still remains uncertain. Moderate to high confidence
  remains for warmer temperatures during the middle of next
  week with high temperatures into the 80s.

&&

.UPDATE...
Issued at 100 AM CDT Sat Jun 8 2024

Light showers over the southeast, LaMoure, Dickey and McIntosh
counties, continued to move southeast and will be out of the
area by 215 am. Surface high pressure ridging into the west will
result in decreasing clouds central and east as those showers
move out. Winds were light and variable for the most part,
except near showers were speeds were 10 to 15 mph. That too
will decrease after the showers move out.

UPDATE
Issued at 834 PM CDT Fri Jun 7 2024

Showers continue mainly in the center through east central
parts of the state. These showers will continue moving east
through the evening hours. There are also scattered popcorn
showers in southern Canada heading towards northern parts of the
state. However, these will likely dissipate as the sun continues
to set. No lightning strikes have been observed for about 45
minutes as of this time. A few more lightning strikes aren`t
totally out of the question, though no instability is being
analyzed on the mesoanalysis page. This suggests less than 250
J/kg of MUCAPE is present, and any limited instability that does
remain will continue to decrease as the sun sets.

UPDATE
Issued at 646 PM CDT Fri Jun 7 2024

Previously quasi-stationary frontal boundary has steadily been
sinking south and is presently over the southernmost tier of
counties. A couple of weak thunderstorms had developed in
eastern Adams and southern Grant counties. The former moved into
South Dakota and the latter has weakened. It remains possible
that a brief strong thunderstorm could develop in far southern
ND, though is looking less and less likely. As the frontal
boundary continues into South Dakota, any remaining threat for
strong storms will diminish over the next hour or so.

Otherwise, scattered showers continue in central North Dakota.
Recently, there were a few lightning strikes in southern McLean
County. However, with the lack of instability, any embedded
thundershowers should be few and far between. These showers will
continue working through to the east southeast and exit the
forecast area late this evening, or shortly after midnight.

&&

.DISCUSSION...
Issued at 255 PM CDT Fri Jun 7 2024

A weak disturbance in northwest flow could still bring showers
and thunderstorms through this evening. SPC maintains a
Marginal Risk of severe weather in southcentral and portions of
southwestern North Dakota through this evening. The threat for
severe weather overall looks very isolated today. Some HRRR
CAMS are showing an isolated stronger storm later this afternoon
into this evening across these marginal risk areas. There is
abundant shear in this area during this time period. The bigger
concern though is the lack of instability. HREF ensemble data
showing MUCAPE up to 500 J/KG. While surface based CAPE is
higher in some instances, the elevated nature of today`s
convection would be tough to tap into this. A quick change from
easterly flow at the surface to westerly flow aloft could be
adding some SRH and perhaps promote weak rotation in isolated
storms, yet again this would require surface based storms. More
looking into the elevated storm environment the hodographs
become more straight. This could still help with hail
production, especially given the high amounts of shear. The
concern still remains the lack of instability. There is a weak
warm front boundary setting up as well in these Marginal Risk
areas. If a stronger storm can get going along this boundary and
pulse up, then perhaps hail up to an inch in diameter and wind
gusts up to 60 mph are possible. For now kept messaging sub
severe as this is where our highest confidence currently
resides given the lack of instability. Precipitation activity
should diminish shortly after midnight tonight. Look for
overnight lows to be in the 40s, and light winds tonight as they
switch back to a westerly direction. A broad upper low then
looks to linger in southern Canada for Saturday maintaining the
near to slightly below normal temperatures across the CWA. The
unsettled northwest flow could result in a few isolated showers
Saturday, with the higher confidence areas coming in the north
where a weak frontal boundary may help with lift. Instability
lacks even more than today, thus left our mention of
thunderstorms for Saturday. Northwest winds may increase
slightly for Saturday, yet be below advisory criteria. Sunday
still remains a day of uncertainty as temperature and
precipitation chances will highly depend on how far south this
cut off low can progress. Clusters are about 50/50 on the low`s
location which brings quite the spread in temperatures. There is
somewhat of consensus that below normal temperatures will be
found. How cold will depend on this location. NBM may have
raised slightly today compared to last night, although this may
be the trend until more model consensus can be found. NBM also
keeps Sunday mainly dry for the time being, again dependent on
the lows placement. A wave moving across the Pacific North West
could then lift across the area Sunday night through Monday.
This will linger cooler temperatures, yet make the next chance
for widespread showers and thunderstorms. There is a high amount
of shear during this time period, although instability looks
limited. The chance for severe weather perhaps will need to be
monitored going forward given the amount of shear available. One
last note for the weekend, cooler temperatures could also be
found in the morning with perhaps some upper 30s possible Sunday
morning.

Ridging to flat ridging could then be found through mid next
week. This westerly flow could bring some warming temperatures,
with NBM placing highs in the mid 70s to mid 80s for much of the
CWA. Flat ridging could promote a few weak waves in the flow and
possibly bring a shower or thunderstorm at times. Predictability
is low for this pattern at this time and left in NBM PoPs for
now. Clusters then indicate perhaps a return to a broad trough
or at least northwest flow pattern. This may slightly cool the
temperatures and bring more chances for showers and
thunderstorms. CSU-MLP putting in some slight chances for severe
weather mid to late next week. These chances are isolated to scattered
and will have to be monitored going forward.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 100 AM CDT Sat Jun 8 2024

South and east of KJMS -SHRA will continue to move southeast and
be out of the area by 08/0715Z. Clouds there will then decrease
with SKC expected over the entire forecast area by 08/09Z.
During the day Saturday -SHRA will be developing but the
coverage of them will be isolated. With relatively dry air at
the surface, as surface high pressure ridges in from Montana,
much of the rain will not be reaching the ground (Virga). With
that, gusty winds as high as G20 knots could result with
variable wind directions.

&&

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

&&

$$

UPDATE...JPM
DISCUSSION...
AVIATION...JPM