Lake Williams State Game Management Area North Dakota Weather Forecast Discussion

342
FXUS63 KBIS 140257
AFDBIS
Area Forecast Discussion
National Weather Service Bismarck ND
957 PM CDT Mon Oct 13 2025
.KEY MESSAGES...
- Subfreezing temperatures are expected across portions of
  northwest and north central North Dakota tonight into Tuesday
  morning.
- Continued cool Tuesday, then warming back up to near or
  slightly above average mid to late week.
- Medium to high chances for rain Wednesday through Friday.
&&
.UPDATE...
Issued at 955 PM CDT Mon Oct 13 2025
No significant changes were needed for the late evening update.
Mid and high level cloudiness will continue to increase from the
south overnight, with low to medium rain chances moving into
the south late tonight. Scattered rain showers will then spread
northeast across the forecast areas during the day on Tuesday,
with very light rainfall amounts expected. QPF amounts will
range from a couple of hundredth of an inch most areas, up to
maybe a tenth of an inch in few locations.
No changes to the current Freeze Warning. Updated text products
will be transmitted shortly.
UPDATE
Issued at 545 PM CDT Mon Oct 13 2025
Clouds remain over northwest North Dakota late this afternoon.
With the clouds, temperatures have only climbed into the mid and
upper 30s. Elsewhere, skies were clear to partly cloudy with
only a few high clouds working their way into the area from the
southwest. Updated sky cover and temperatures to account for the
increased clouds and lower temperatures in the northwest,
otherwise no updates were needed.
&&
.DISCUSSION...
Issued at 230 PM CDT Mon Oct 13 2025
Another quiet weather day is due for the books as Canadian high
pressure settles over the northern Plains through the day
today. With this, generally calm winds and clearing skies from
south to north are anticipated across North Dakota through this
afternoon and into early this evening. With a much cooler
airmass draped over the region today, and with low level clouds
lingering across the far northwest, high temperatures are
broadly anticipated to broadly peak only into the 40s and 50s
this afternoon, with some upper 30s possible in the far
northwest. With this setup, low temperatures across the north
are anticipated to drop to or slightly below freezing again
tonight. Thus, a Freeze Warning is again in effect for the 2
northern most tiers of counties from 8 PM CDT tonight through 10
AM CDT Tuesday morning.
Flow over the northern Plains is expected to turn increasingly
southwesterly through the late afternoon and evening today as an
aggressive upper level trough/closed low makes landfall into
the western CONUS. A weak shortwave impulse ejecting off of this
low is progged to break over the northern Plains tonight
through much of Tuesday, promoting an increase in cloud cover
and medium chances (25 to 55 percent) for rain across much of
western and central North Dakota through the day on Tuesday.
Overall rainfall amounts from this wave of precipitation are
anticipated to be fairly low, below a tenth of an inch
everywhere. Otherwise, for Tuesday, cool highs mainly in the
mid 40s to lower 50s are anticipated.
Looking ahead to the later half of the workweek, the northern
Plains will fall increasingly under the influence of the upper
level low as it moves eastward through Saturday. Ahead of this
low, a transient upper level ridge late Tuesday through
Wednesday will help dry conditions out, a instigate a slight
warming trend through Friday that will bring much of the
forecast area back in to the 50s and lower 60s. Notably, with
this heating occurring just before the main wave moves into the
northern Great Plains late Wednesday, the development of
thunderstorms is not out of the question. An interrogation of
model soundings during this period reveals an elevated and
skinny CAPE profile, with MUCAPE values approaching 500 to 750
J/KG across the southwest and south central Wednesday evening.
With high bulk shear values, broadly from 45 to 55 knots across
the same area, an isolated strong to marginally severe
thunderstorm is not out of the question during this period. The
SPC currently has a level 1 of 5 risk for isolated severe
thunderstorms for Wednesday, while the CSU paints a low
potential highlight for severe hail for this same period across
far southwestern and far south central North Dakota.
In any scenario, medium to high chances (60 to 90 percent) for
widespread rain increases Wednesday through Thursday as the
upper level low skirts across the western half of the state,
with medium chances (30 to 50 percent) lingering through much of
Friday. The rainfall totals during this period are somewhat
dependent on what forecast scenario that plays out, with two
ensemble clusters evident at the time of this forecast. The
first is a plurality solution (45 percent of ensemble members),
which favors a comparably stronger and faster upper level low
arriving Wednesday evening. This scenario would be the wetter of
the two, with rainfall totals approaching 0.75 to 1 inch across
much of the forecast overall by late Friday, with portions of
the north potentially even exceeding 1 inch. The second of the
two clusters has slightly lower buy-in (35 percent membership),
and is comparably dry, with the much broader/opening upper level
low that only starts to arrive some time Thursday morning. As
the drier of the two scenarios, much of the forecast area would
struggle to exceed 0.25 to 0.5 an inch of rainfall overall. Of
note is that this clustering run did not include any members of
the GEPs, which accounts for the missing 20 percent of ensemble
members, and that each cluster is highly biased toward one
ensemble family or another, with the wet solution mainly
belonging to ENS members, and the dry solution main comprised of
GEFs members. In either scenario, rainfall totals could be
bolstered by convectively-enhanceed precipitation across the the
southwest and south central on Wednesday, and possibly again
across central North Dakota on Thursday.
Looking ahead to this weekend, conditions are anticipated to
start drying out from west to east through early Saturday as a
the inciting upper level low moves off to the east, and an upper
level ridge builds in across the northern Plains. While morning
low temperatures do tickle freezing both Saturday and Sunday
morning, more broadly a slight warming trend is anticipated
through the weekend and into early next week, with highs broadly
in the mid 50s to mid 60s Sunday and Monday. The ensemble
becomes increasingly discordant through the end of the forecast
period, with some uncertainty as to how quickly the upper level
ridge moves off to the east. Long-term models generally agree on
the development of another transient upper level trough digging
down out of the Canadian Prairies some time in the first half
of next week, which could signal a return of cooler and wetter
temperatures, but the timing and location of such is fairly
uncertain this far ahead of time.
&&
.AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/...
Issued at 545 PM CDT Mon Oct 13 2025
MVFR ceilings continue to hold on over far northwest ND,
including at KXWA. Therefore, MVFR ceilings here to begin the
00Z TAF period. MVFR ceilings are expected to lift at KXWA this
evening with VFR ceilings through the remainder of the TAF
period. Elsewhere only a few high clouds and VFR conditions
expected this evening and overnight. We will see increasing
clouds tonight and lowering ceilings late tonight through the
day Tuesday. A band of shower activity is expected to lift
north through the forecast area during the day Tuesday. Covered
this with a PROB30 at all TAF sites except KXWA. Currently
precip is more focused on central ND so kept precip chances out
of KXWA and only a brief PROB30 at KDIK. MVFR ceilings are
expected to increase across the forecast area Tuesday afternoon
but there are some uncertainties in how quickly this will occur.
For now kept timing a bit later that NBM guidance would
suggest, but will continue to monitor. Generally light north to
east flow to begin the TAF period will become east to southeast
on Tuesday and increase, with winds 15 to 25 mph by Tuesday
afternoon.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
Freeze Warning until 10 AM CDT Tuesday for NDZ001>005-009>013.
&&
$$
UPDATE...TWH
DISCUSSION...Adam
AVIATION...TWH

NWS BIS Office Area Forecast Discussion