958
FXUS63 KBIS 120838
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
338 AM CDT Mon May 12 2025

.KEY MESSAGES...

- Scattered showers and isolated thunderstorms will continue to
  diminish this morning. Some gusty winds will remain possible
  under these showers and storms.

- Critical fire weather conditions expected to remain in place
  through early this evening across south central North Dakota
  and much of the James River Valley.

- Hot, dry, and breezy conditions to continue today, with
  record high temperatures possible once again.

- Near-critical to critical fire weather conditions may
  continue into Tuesday.

- Higher chances for rain and much cooler temperatures return
  for the second half of next week.

&&

.DISCUSSION...
Issued at 338 AM CDT Mon May 12 2025

As of early this morning, a weak upper level shortwave
continues to move through the northern Plains as a surface low
is located over north central North Dakota. A surface trough
extends to the south of the low and has been the main focus of
some scattered showers and isolated thunderstorms. While this
activity has diminished substantially since last night, we are
still seeing some periodic wind gusts in the 35 to 45 mph range.
Most of the CAMs snuff this activity out over the next hour or
two, but they have not had a great handle on it. So, wouldn`t be
surprised to see at least some isolated showers and storms
linger through the morning.

Yet again, the main story for today will be fire weather
concerns. The Red Flag Warning continues to be in good shape
with one more day of headlines possible on Tuesday. For
specifics, see the Fire Weather Discussion below.

Western and central North Dakota will remain in southwest flow
aloft through the day as another shortwave skirts the northwest
late this afternoon and into this evening. While most of the
forcing will remain west and north of our area, there could be
enough of a glancing influence to spark a couple of isolated
showers/storms across the far northwest or far north central.
Thus, we will carry low chances (20 percent) here from around
22z through 06z, matching the timing currently being advertised
by the few CAMs that develop convection in our area.

It will also be another hot and dry afternoon today with all
the usual signals describing anomalous heat for this time of
year. For highs today, we trended towards the NBM 75th
percentile again and the NBM 10th percentile for afternoon
dewpoints. Similar to yesterday, we should see highs in the 90s
across all of western and central North Dakota with possibly a
few sites reaching 100 over the north central. High temperature
records were broken at Minot and Jamestown yesterday and
Bismarck tied theirs. It seems likely that several more records
will be broken today. We will also see another round of gusty
southerly winds today across portions of the central and into
the east. The strongest winds will be over the James River
Valley where we could see some sustained values up to 30 mph and
gusts to 45 mph. Similar to yesterday, some consideration was
given to issuing a Wind Advisory, but will let the Red Flag
Warning continue to advertise the wind threat here.

A cold front will approach from the west tonight, moving across
the state from west to east through the day on Tuesday. This
will bring some relief to the heat across the west with highs
here forecast to be in the mid 70s to lower 80s. However, it
will remain hot ahead of the front with highs expected in the
upper 80s and lower 90s over the central and east. We could see
two areas of breezy to windy conditions on Tuesday, southerly
ahead of the front and northwesterly behind the front.

By late Tuesday afternoon or evening, showers and storms are
forecast to develop along the front but most of the day should
remain capped. Forecast soundings suggest some decent
instability along this boundary but the strongest shear is
forecast to lag behind. Thus, a stronger storm or two cannot be
ruled out but the severe weather threat appears to be low.
Most guidance develops more convection overnight as the core of
the trough approaches, providing strong lift for large scale
ascent.

Wednesday still appears to be the best day for some strong to
severe storms and much will depend on the evolution of early day
convection and subsequent cloud cover. The front will stall out
somewhere across the central or east and will be the focus for
later day convection. Guidance does show the best shear lagging
the best instability earlier in the day but we could see 500 to
1000 J/kg of MUCAPE overlapping 45 knots of deep layer shear by
the early evening. Shear vectors appear to be fairly parallel
to the boundary so quick upscale growth to linear structures
seems to be the most likely scenario for storm mode at the
moment. SPC has placed most of our central and east in a
Marginal Risk (level 1 of 5) of severe weather in their latest
Day 3 convective outlook so we will continue to monitor the
evolution of the threat as we move closer. Temperatures on
Wednesday will be cooler across the board, especially across the
west. Forecast highs are expected to range from the lower 60s
west to the mid to upper 80s over the James River Valley. Most
of the central will see highs in the 70s.

Widespread medium to high precipitation chances (60 to 90
percent) continue Wednesday night through at least Thursday
night, with low to medium chances (20 to 50 percent) diminishing
from west to east on Friday. Temperatures will be quite cool
Thursday through the weekend. Highs on Thursday will range from
the lower 50s northwest to the mid to upper 60s southeast.
Northwest winds are also forecast to be quite strong on Thursday
which could make it feel even cooler. Then, for Friday and
Saturday, the NBM suggests highs ranging from the mid to upper
40s over the Turtle Mountains, to the lower 60s southwest. On
Sunday, expect highs in the 50s pretty much everywhere. Lows
will be quite chilly each night Thursday through Sunday with
widespread readings in the low to mid 30s (possibly even some
upper 20s north). Thus, we may be talking about some
frost/freeze potential to end the week/weekend so stay tuned.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1224 AM CDT Mon May 12 2025

Scattered showers and isolated thunderstorms continue to move
through western and central North Dakota. Winds have been gusty
and erratic under this activity and will continue as showers and
storms move overhead, diminishing over the next few hours. Some
brief MVFR visibilities will be possible under the heaviest
showers/storms. VFR conditions are expected to prevail after
this activity moves out/diminishes. It will remain breezy to
windy through the period across much of the central and east.
Some enhanced low level wind shear will also remain possible at
KBIS and KJMS through the overnight hours.

&&

.FIRE WEATHER...
Issued at 338 AM CDT Mon May 12 2025

For today, hot and very dry conditions will continue across
much of western and central North Dakota, bringing more near-
critical to critical fire weather conditions. Portions of the south
central and much of the James River Valley are expected to see
gusty southerly winds once again, leading to more critical fire
weather conditions. Red Flag Warning remains in effect here
through early this evening. Elsewhere, expect near-critical fire
weather conditions. Look for somewhat improved humidity
recoveries tonight.

Near-critical to critical fire weather conditions may then
return on Tuesday. Timing of a cold front combined with
uncertainty in fuels has cause for holding off on additional
fire weather products at this time.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 9 PM CDT /8 PM MDT/ this evening for
NDZ022-023-025-035>037-045>048-050-051.

&&

$$

DISCUSSION...ZH
AVIATION...ZH
FIRE WEATHER...ZH/Anglin/JJS