044
FXUS63 KBIS 191943
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
243 PM CDT Wed Jun 19 2024

.KEY MESSAGES...

- Hit or miss showers (20 to 30 percent) are possible today
  through Thursday. Better chances for showers and thunderstorms
  (40 to 70 percent) return Thursday night through Saturday.

- A slow warming trend is expected heading into the weekend and
  early next week, with highs approaching the upper 80s and
  lower 90s by Monday.

&&

.DISCUSSION...
Issued at 239 PM CDT Wed Jun 19 2024

Surface high pressure is positioned across north central North
Dakota, slowly drifting east through the day, as southwesterly flow
aloft remains across the Northern Plains. Mostly clear skies and
relatively light winds are present across much of western and
central North Dakota as a result, with a few fair weather cumulus
clouds forming and moving north across the far northwestern corner
of the state. As the surface high pressure drifts east, southerly
flow across the far western portions of the state will increase
enough to provide some low chances for showers later tonight, with
the highest chances across the southwest and northwest corners (both
roughly 15 to 25 percent). CAMs don`t show much when it comes to
these little waves of precipitation, but its certainly a possibility
that some areas may see a sprinkle, and possibly even some thunder.
Probabilities for anything producing any lightning is near zero, but
not completely out of the question.

This southerly low level flow continues on Thursday, as cloud
coverage and chances for showers slowly increase across the area,
from south to north. As such, high temperatures across the south
will be tempered just a bit, with values in the upper 60s across the
south, ranging to the mid 70s across the north. With the continued
southwesterly flow aloft, messy shortwaves embedded within the flow
will lead to disorganized showers across the area. PoPs across the
the area will be in the 30 to 60 percent range across the southern
half of the area, with the highest chances arriving later Thursday
night. There will also be a corridor of increased instability just
north of the International Border, due to the warmer temperatures up
there, which could lead to some isolated thunderstorms near the
border. The highest CAPE values are positioned entirely outside of
our area, so the chance for these storms are once again rather low.

Showers and possible some thunderstorms continue through the day
Friday, covering nearly the entire area with at least a 40 percent
chance for showers by Friday evening, with the southern half of the
area seeing chances from 60 to 70 percent. Thunderstorms are once
again possible, given the marginal instability and very pronounced
shear, but the instability maximum once again resides just outside
of our area, this time to our southeast. The SPC has outlined much
of eastern South Dakota in a Marginal Risk (level 1 of 5) for severe
thunderstorms, but this risk stops right before it reaches the North
Dakota border, near the southern James River Valley region. We will
continue monitoring this situation in case some of the ingredients
needed for severe weather begin to shift north. Regardless, much of
the area will see a slight chance for some thunder Friday evening.

Saturday will see the beginning of a drying trend, as an upper level
trough to our northwest begins to shift eastward, placing North
Dakota under more of a zonal flow aloft. Model ensembles are still
not very tight from this weekend onward, but the general consensus
is that this weekend and the start of next week will be mostly dry,
with weak embedded impulses bringing low chances for precipitation
nearly daily (with chances around 15 to 30 percent). Upper
level ridging to our west may begin to slide east through Sunday
and Monday, with NBM high temperatures suggesting the
possibility for widespread highs in the upper 80s to lower 90s
by Monday. NBM spreads for Monday in particular are rather low,
which indicates increased confidence that pretty warm
temperatures are expected that day. These spreads then begin to
increase quite a bit from Tuesday onward. Despite the spreads
and uncertainty increasing during that period, the general trend
of temperatures gradually decreasing is prevalent. The
continued mostly zonal westerly flow aloft is expected to remain
through the middle of next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1236 PM CDT Wed Jun 19 2024

VFR conditions are present across all terminals, and will remain
VFR through the TAF period. Surface high pressure sits across
the area, with light winds across all sites except KXWA, and some
fair weather cumulus beginning to form in the northwest. KXWA
will see some slightly gusty southerly winds, with some gusts to
around 20 kts possible at times during the day. Lower clouds and
chances for rain begin to build into the far south near the end
of the TAF period.

&&

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

&&

$$

DISCUSSION...Besson
AVIATION...Besson