144
FXUS63 KBIS 101749
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1249 PM CDT Thu Jul 10 2025

.KEY MESSAGES...

- Isolated severe thunderstorms are possible this afternoon and
  evening across parts of southwest and central North Dakota.

- Temperatures will cool down to the 70s for most locations on
  Friday, before warming back up again for the weekend.

- A more active pattern returns for the start of next work week.

&&

.UPDATE...
Issued at 1237 PM CDT Thu Jul 10 2025

Some showers and thunderstorms are forming across the eastern
half of the state into the James River Valley. No updates are
needed at this time as the forecast remains on track.

UPDATE
Issued at 932 AM CDT Thu Jul 10 2025

Quiet weather continues across the region this morning. A cold
front continues to slowly progress out of southern Saskatchewan
this morning shifting the winds out of the north. No updates are
needed at this time as the forecast remains on track.

UPDATE
Issued at 638 AM CDT Thu Jul 10 2025

Isolated showers and a few rumbles of thunder have been ongoing
across the north central, slowly moving east, with any one
shower not lasting particularly long before diminishing. Surface
trough is oriented more north-south and is moving into western
North Dakota, while the cold front is more west-east and is
north of the International Border.

Latest high-res guidance paints a similar picture for this
afternoon and evening. As the surface trough drifts east, could
see some scattered convection across the south central and east,
with the environment becoming more unstable the further east you
go. Then, the cold front sweeping through brings additional
chances of showers and thunderstorms to the north, which we
still think is almost a more favorable environment for strong to
severe storms as bulk shear is projected to increase across the
north as the front moves through. Guidance is beginning to more
consistently advertise precipitation across the north late this
evening, although could be too capped for too robust of
development. Main change was to update POPs for latest blended
guidance, otherwise going forecast looks good for now.

&&

.DISCUSSION...
Issued at 352 AM CDT Thu Jul 10 2025

This morning, a closed low was analyzed in northern Saskatchewan
with quasi-zonal flow across North Dakota. A second, shallower
trough was located in southern Idaho, with downstream troughing
across the Ohio Valley region. A surface low was centered in
northern Manitoba with a trailing surface trough extending
southwest across the northwest corner of the state into eastern
Montana. Light, scattered radar returns have been consistent
across the forecast area and into Montana, but no evidence of
any rain at the surface, and ceilings are quite high. We are
starting to see some flashes of lightning in the northwest,
where it is uncapped but with limited instability. It`s a
seasonably warm night, with some stations in western North
Dakota seeing temperature spikes as winds increase and mix down
the warm 850mb temps.

The approaching trough base to our north will slowly shift
south, with the aforementioned surface trough then a cold front
moving through the forecast area that will provide forcing for
showers and thunderstorms today and tonight. There are two main
areas to focus on for precipitation -- south central /
southeast this afternoon and evening with the trough, and then
this evening/tonight with the cold front. The likelihood of
severe weather continues to decrease, with only isolated severe
thunderstorms possible (level 1 out of 5) with this update.
Instability is projected to be lower than previously thought
across the forecast area, ranging from around 1000-2000 J/kg
central to 3000 J/kg east (which is still notable, just not
extreme bouyancy like we had been seeing in previous model
runs). Bulk shear continues to be the limiting factor, with many
locations seeing those higher instability values also only
having 20 to 25 knots of 0-6km shear. There is perhaps a
slightly higher threat ceiling across the north central where by
late this evening, deterministic guidance increases shear to 30
to 35 knots. The 00Z HREF paints a few longer UH tracks through
this area, and some CAMs want to have at least scattered
convection at a similar time and area, so worth watching for a
later window of stronger storms. Machine learning guidance has
trended down for today, with CSU advertising low probabilities
for severe hail generally central and east, with a slight
increase for the northeast corner of the state. NSSL is also
advertising lower probabilities compared to previous, echoing
the theme that model guidance is not sold on the environment
today.

Opted to broad-brush low POPs this afternoon and evening south
central and then north, with widely scattered showers and
thunderstorms expected. Highs will be in the mid 80s northwest,
where cold air advection will arrive first, and in the upper 80s
to mid 90s elsewhere. Humidity will still be high central and
especially east, with dew points approaching 70 degrees in the
James River Valley.

Scattered showers and thunderstorms are likely to continue
through Friday morning and into the afternoon as the upper
trough base moves across the state, while surface high pressure
attempts to build in behind the cold front. Temperatures will be
much cooler, with highs generally in the 70s, and could see some
lower 80s southeast. A northwest breeze will keep winds
sustained around 15 to 20 mph, diminishing in the evening.

Flow aloft turns northwesterly on Saturday, with a passing
impulse progged to bring an increase in cloud cover but no
precipitation chances. Highs will be in the upper 70s to mid
80s, quite seasonable, warming further on Sunday as a low level
thermal ridge moves in and boosts temperatures back into the mid
80s to lower 90s.

A more active pattern begins for the start of next work week,
with increasing precipitation chances and temperatures cooling
down through midweek, before a warming signal returns for next
weekend.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1237 PM CDT Thu Jul 10 2025

VFR conditions will continue across the region today with a low
chance of thunderstorms forming this afternoon and evening. The
models are beginning to agree on a cluster of thunderstorms
moving out of southern Saskatchewan into the northern half of
the state tonight so the prob 30s for KXWA will remain and a
new prob 30 was added to KMOT. There are also some showers
trying to go up in the James River Valley right now (18Z), so
the prob 30 will remain for KJMS as thunderstorms could still
form in the vicinity of the terminal. Winds will switch out of
the north to northwest tonight as a cold front moves through the
region.

&&

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

&&

$$

UPDATE...Johnson
DISCUSSION...Jones
AVIATION...Johnson