142
FXUS63 KBIS 020036
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
736 PM CDT Mon Jul 1 2024

.KEY MESSAGES...

- There is a Marginal Risk (level 1 of 5) to Slight Risk (level
  2 of 5) for severe thunderstorms through this evening for
  portions of the south central into the James River Valley. The
  main hazards are hail up to quarter size and wind gusts up to
  60 mph.

- Isolated to scattered thunderstorms possible Tuesday and
  Wednesday. An isolated severe thunderstorm is possible
  Wednesday, mainly in the southwest.

- The chance for showers and thunderstorms on Independence Day
  is 60 to 80 percent across all of western and central North
  Dakota.

&&

.UPDATE...
Issued at 733 PM CDT Mon Jul 1 2024

We have cancelled the severe thunderstorms watch for a good
portion of south central ND. Will leave it going, at least for a
while over Emmons county and into the James River Valley.
However the severe threat looks to continue to diminish. Will
monitor.

UPDATE
Issued at 618 PM CDT Mon Jul 1 2024

Thunderstorms have exited the Bismarck Mandan metro area.
However, the 00Z sounding indicates little to no CIN behind the
convection. Therefore, until the secondary boundary over western
Morton and Grant counties, there remains at least a small severe
threat. Will hold on to the watch west of the river for a while.

For areas to the east, including the James River Valley, the
greatest threat could be very heavy rain. Fortunately so far
this evening, with a strong shortwave, the convection has
progressed quickly to the east. Which is good given the very
high PWATS over the area this evening. The convection is moving
into a more capped environment so the threat for severe storms
may diminish as the convection moves east. Will continue to
monitor.

&&

.DISCUSSION...
Issued at 314 PM CDT Mon Jul 1 2024

Cold front is still expected to bring showers and thunderstorms
through this evening. Isolated to scattered severe thunderstorms
are still expected. Main threats will be hail up to ping pong
ball size and wind up to 60 MPH. These threats could be high if
storm mode takes on more discrete characteristics. For the
latest breakdown on the environment see the mesoscale
discussion. Timing wise look for these stronger storms to get
going mid to late afternoon then pushing eastward through the
evening. Some breezy southerly winds are possible through this
evening ahead of this front, although winds have generally
trended lower than previous forecast today. Most of the severe
weather will exit or dissipate tonight. A broad trough lingering
in the north could bring an isolated shower or perhaps
thunderstorm in these areas tonight, with a low threat for
severe weather. Low temperatures tonight will generally be in
the 50s.

This broad trough then looks to linger across the state on
Tuesday, and perhaps bring a secondary cold front Tuesday
afternoon through the evening. The result will be isolated to
scattered thunderstorm chances through the day, with higher
chances in the north. Instability and shear are limited for
Tuesday, thus severe weather is not expected at this time. Look
for temperatures in the 70s. Breezy northwest winds are also
possible for Tuesday. The upper level winds are not
particularly strong, and ECMWF EFI values are fairly low. Thus
advisory level winds are not expected at this time. A quiet
night with lows in the 50s are then expected for Tuesday night.
Another broad trough still looks to push across the state on
Wednesday. This could bring more scattered chances for showers
and thunderstorms. Instability still looks somewhat limited
although shear is increased on this day. Perhaps an isolated
stronger storm is possible, especially in the south. SPC
currently has a Marginal Risk in the southwest. High
temperatures on Wednesday will warm slightly in the mid 70s to
mid 80s.

The broad trough could still develop a cutoff low across the
region on Independence Day. This could still bring widespread
showers and thunderstorms. Of note that some clusters have this
low further south which would bring less rain to the are. This
southern solution equates to about a 40% chance of occurring,
with a 60% chance of the low maintaining a similar track that
has been forecasted. Either solution would bring cooler
temperatures to the area in the low to mid 70s. Clusters then
show northwest flow through the Holiday weekend, although a
building ridge in the west could attempt to push more eastward
later in the weekend. Temperatures could warm to near normal as
a result, and perhaps slightly warm if the ridge can build
further inland. Chances for showers and thunderstorms will be
found each day, with the potential for waves to traverse through
this northwest flow. CSU-MLP pops for severe weather are low
for severe weather during this time period.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 618 PM CDT Mon Jul 1 2024

Scattered to numerous showers and thunderstorms currently over
central ND will track east across central and into into eastern
ND this evening. A cold front over western ND will move east
through central and eventually the JRV later tonight, ending the
threat of thunderstorms. Through teh rest of the evening the
greatest threat for strong to severe storms will be over KJMS,
but at least a small threat of thunderstorms will exist until
the cold front passes, and it has passed through KDIK and KXWA.
Southerly winds 15 to 25 mph will shift westerly behind the cold
front 5 to 15 mph. VFR conditions are expected behind the cold
front tonight. On Tuesday MVFR ceilings are possible across
northern ND, including KXWA and KMOT. Otherwise VFR conditions
are expected with a westerly wind becoming gusty in the
afternoon around 15 to 25 mph.

&&

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

&&

$$

UPDATE...
DISCUSSION...
AVIATION...TWH