222
FXUS63 KBIS 290537
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1237 AM CDT Sat Jun 29 2024

.KEY MESSAGES...

- Showers remain possible through late tonight.

- Expect breezy conditions at times overnight.

- Severe thunderstorm potential (a Level 2 of 5 Risk) in the
  form of large hail and damaging winds returns Sunday night.

- Severe thunderstorm potential could continue for Monday,
  especially in south central and southeastern North Dakota.

&&

.UPDATE...
Issued at 1236 AM CDT Sat Jun 29 2024

Minimal changes were made to the forecast for this update. The
lingering precipitation has begun to trend downwards, which is
still in line with what we are thinking for the next few hours.
Low clouds continue to slowly build south, with some drizzles
being reported at times in some locations where ceilings drop
down even further. Breezy conditions remain across the north,
with a brief period of breezy winds in the James River Valley
overnight on the back side of the surface low that is currently
making its way through northern Minnesota. Some areas across the
north central continue to see some patchy fog as well.

.UPDATE...
Issued at 938 PM CDT Fri Jun 28 2024

An upper level low continues to track east across the forecast
area. Showers continue to dissipate quickly this evening. Have
updated pops to account for this. Will allow the wind advisory
to expire at 9 PM MDT. Breezy conditions at times will continue
through the night. behind the exiting low. Late this evening
and overnight low level cloudiness will also increase from north
to south with low clouds forecast to cover much of the forecast
area by Saturday morning. We also added some patchy fog to
portions of the north central. Rolla already has some fog and
mesoscale models hint at some areas of fog in the north central
overnight.

.UPDATE...
Issued at 601 PM CDT Fri Jun 28 2024

Upper level low has moved into North Dakota and is situated
near Williston and moving to the east. An areas of 500-1000 J/kg
of CAPE is situated over northern ND which is within an area of
40-50kts of bulk shear. Showers continue to develop over central
ND and as this low impedes upon this area of instability, a few
strong to severe storms can not be ruled out this evening. there
is instability (500-1000J/KG MLCAPE) that does extend south
into south central ND, but forcing here is not as strong. Under
the upper low, scattered showers and isolated thunderstorms
will continue. The Non-supercell Tornado parameter remains high
over northwest ND and also portions of the north central. Low
level lapse rates remain high over central ND, and funnel clouds
or a possible landspout tornado can not be ruled out as well.

Updated sky cover and pops based on latest satellite and radar
analysis. A wind advisory remains in effect through 9 PM MDT.
Winds this last hour were gusting to 37 knots at Baker MT. Will
continue the advisory.

&&

.DISCUSSION...
Issued at 304 PM CDT Fri Jun 28 2024

Upper level low will push across North Dakota through tonight.
Late this afternoon through this evening will see widespread
showers with a isolated to scattered thunderstorms. SPC has
maintained a Marginal Risk across central and eastern ND. These
areas could see MUCAPE up to 1000 J/KG, while shear remains
quite robust around 50 knots, although does look to diminish as
the day goes on. Hodographs are not very curved but are fairly
straight which could help hail production. Given the adequate
amounts of instability and shear decided to add mention of
quarter size hail and 60 MPH wind gusts in areas in the Marginal
Risk. Of note is a high Non Supercell Tornado Parameter
currently in MT and Canada that will advect this way. Meso
analysis also shows fair amounts of low level cape and steep low
level lapse rates in the north this afternoon into the early
evening. Thus a funnel cloud to perhaps brief landspout tornado
are possible today. The north (Highway 2 corridor and north) to
the James River Valley may have a slightly better chance of
this occurring, although will be possible most anywhere with a
Marginal Risk. This wrapped up low has also brought some breezy
winds to ND and windy conditions in Montana. As this low
progresses through these stronger winds will also push through.
Confidence in the strongest winds still remains in the Wind
Advisory area, thus no expansion at this time. Tonight,
thunderstorms will diminish although a few showers will be
possible. Low clouds will be found through the night as well
from this low. Mixing looks to be enough to prevent fog,
although perhaps some mist or drizzle is possible from these
clouds. Surface high and upper level ridge will then push across
the state on North Dakota. This will gradually erode clouds,
with cooler temperatures in the 60s expected. Winds will also
diminish, although may be breezy across the east. High moves
eastward on Sunday with southwest flow aloft and southerly flow
at the surface moving in. Warming temperatures and breezy to
windy conditions will be found. Perhaps these winds get near
advisory level as the EFI is elevated in the southwest. Severe
weather then remains possible for Sunday evening through Sunday
night as an upper level wave moves through. A strong low level
jet will also help support the severe weather potential. Kept
the hazards generic for now, although this could be more of a
wind threat with the strong shear vector along the front axis.
There still could be enough elevate cape for a hail threat as
well. Will continue to monitor and SPC currently has a Marginal
to Slight risk for this threat. This wave remains across the
area on Monday. This could bring continued unsettled weather
with near normal temperatures. SPC has a Day 4 risk outlook for
south central and southeastern ND. This is where the highest
instability is currently forecast, although much of the CWA
sees at least modest instability and decent amounts of shear.
Something to monitor going forward.

The state then looks to remain in a broad to flattened trough
pattern through much of next week. Overall this brings an
unsettle pattern with temperatures near to slightly below
normal. Near daily chances for showers and thunderstorms will
also be found in this pattern. THE CSU-MLP also puts almost near
daily small chances for isolated severe weather each day. This
far out it is tough to pinpoint timing and location, yet those
with outdoor plans for next week will want to keep an eye on the
latest forecast.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1236 AM CDT Sat Jun 29 2024

IFR ceilings are present across much of the northern parts of
the state, as a large area of low clouds continues to slowly
expand south through the night. MVFR/IFR ceilings are
anticipated at all terminals through the overnight hours, with
these clouds clearing from north to south through the morning
hours on Saturday. Initially breezy winds in the north will
decrease overnight, with light and variable winds forecast
across the area through the second half of the TAF period. Some
drizzles and showers are possible overnight, especially in
locations where the cloud decks are the lowest. Patchy fog is
possible across the north central from roughly 09z to 12z as
well, which may reduce visibilities in localized areas.

&&

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

&&

$$

UPDATE...Besson
DISCUSSION...Anglin
AVIATION...Besson