000
FXUS63 KBIS 130322
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1022 PM CDT Fri Apr 12 2024

.KEY MESSAGES...

- Warmer today and continued mild through the weekend and to
  start the work week.

- Increasing rain chances next week, especially Monday night and
  Tuesday, with greatest chances (60 to 80 percent) coming to
  central and into eastern North Dakota.

- Colder temperatures mid to late in the work week with
  lingering chances (30 to 60 percent) for rain and snow.

&&

.UPDATE...
Issued at 1017 PM CDT Fri Apr 12 2024

Showers will continue to move in from eastern Montana to western
North Dakota. Rain has been reported at Glendive in the last
hour, therefore PoPs were added to portions of western North
Dakota. The warm front is the lifting mechanism for the showers
out west. The warm front is also ushering in a wind shift. Other
then updating PoPs, no other updates are needed at this time as
the forecast remains on track.

UPDATE
Issued at 621 PM CDT Fri Apr 12 2024

Quiet weather continues across the region. A warm front
continues to move through western North Dakota with temperatures
above 70 in eastern Montana. No updates are needed at this time
as the forecast remains on track.

&&

.DISCUSSION...
Issued at 255 PM CDT Fri Apr 12 2024

An upper level ridge continues to push across the Central Plains
today, with northwesterly flow becoming increasingly zonal through
this afternoon and overnight. A weak bundle of shortwave energy is
moving down this ridge, with an attendant low center at the surface
moving across Montana this afternoon. With high pressure lingering
over southern Manitoba, a modest pressure gradient across western
North Dakota will promote breezy south winds this afternoon that
will shift eastward overnight. Paired with minimum relative
humidities in the upper teens to lower 20s, near critical fire
weather conditions will be present across portions of western
and central North Dakota this afternoon. Otherwise, the sky
remains sunny across the south, with some mid to high level
clouds moving across the northern counties. Highs today range
from around 60 east to the lower 70s west.

Overnight tonight, the low center currently over Montana will push
eastward across the International Border, and with it an associated
warm front. Mid level forcing along with the WAA ahead of this front
will promote some low chances (15-25%) for rain across the north
overnight through Saturday morning. A following weak cold front will
then push across North Dakota through the day Saturday and into
Sunday, with winds veering toward the north through the afternoon.
Otherwise, unseasonable warm temperatures are on tap over the next
few days, with highs in the upper 60s and 70s forecast for Saturday,
Sunday, and Monday.

Chances (40 to 60 percent) for precipitation return late Saturday
into early Monday, as the formation of low center in the lee of the
Rockies pulls another warm front across the northern Plains. With
some models resolving on modest instability being available across
portions of northern and central North Dakota, there are some
chances (10 to 20 percent) for thunder overnight during this period.

Behind this initial wave of precipitation, a much more active
pattern returns to the Central Plains for much of next week. The
overall ridging pattern we experience through the weekend is
diminished and shunted north and east out of the region ahead of a
strong southern stream low. The lifetime of this upper low, and its
interaction with another stream low moving out of north from
Canada will generally characterize how the system will behave.

The surface low forming off the lee of the rockies is currently
favored to take a path out from northeastern Colorado late
Monday, across Nebraska and southeastern North Dakota on
Tuesday, then through Minnesota and into the Great Lakes Region
by the end of the Day Wednesday. With it, widespread chances (60
to 80 percent) for precipitation track across western and
central North Dakota Monday evening through late Tuesday night.
Cluster analysis reveals two scenarios depending on the
interaction of the two upper level lows. Scenario 1 has slightly
higher membership buy in (~60 percent of ensemble members), and
is the wetter of the two scenarios. In this solution, the two
upper level lows begin to merge together early on Tuesday, and
result in a slower, more northerly surface low. Scenario 2 (~40
percent membership) is the drier of the two, and results in the
lows either merging much later on Tuesday, resulting in a much
more progressive low moving further to our south and east. In
either scenario, the heaviest precipitation is currently
tracking across the south central/ James River Valley area.
Potential instability becomes increasingly available through the
day Tuesday, allowing for the possibility for thunderstorms
across the south and into the James River Valley. Where
convection does occur, locally enhanced precipitation would be
expected.

As the surface low continues tracking to our east Wednesday and
Thursday, wrap around precipitation chances (30 to 60 percent)
continue. With a cooling trend accompanying this system, with highs
forecast broadly in the 30s by Thursday, the favored precipitation
type transitions from rain to snow through the morning on Wednesday.
Light accumulations are possible through the end of the week, with 1
to 2 inches possible across the southwest and central, and 2 to 3
inches possible across the northwest. Temperatures are then favored
to begin recovering on Friday as modest upper level ridging begins to
build in from the west, meaning any snow accumulations are not
likely to last beyond the end of the workweek, if even that
long.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 621 PM CDT Fri Apr 12 2024

VFR conditions will continues through the period. Southerly
winds will veer out of the northwest by tomorrow afternoon as a
front moves through region. Low level wind shear is possible
across the central half of the state tonight.

&&

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

&&

$$

UPDATE...Johnson
DISCUSSION...Adam
AVIATION...Johnson