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325
FXUS63 KBIS 192034
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
334 PM CDT Sat Aug 19 2017

.SHORT TERM...(This evening through Sunday)
Issued at 330 PM CDT Sat Aug 19 2017

Concerns for the short term include the critical fire weather
conditions southwest for low humidity and gusty west winds today.
For this a red flag warning continues for the southwest. Later
tonight there is a chance of showers and thunderstorms south that
may linger into Sunday morning.

Currently at the surface, a low was at the central border of
Saskatchewan/Manitoba with a trough extending south to Stanley/Minot
to between New Salem/Bismarck. More humid air with dewpoints in the
upper 50s and lower 60s were ahead of the trough, with drier air
behind it with dewpoints lowering into the lower 50s and 40s. This
trough will continue moving east tonight, with a cold front
following with winds becoming northwest and gusty. This cold front
extended from the Canadian low to near Williston, approaching
Dickinson, and through Bowman as of 2 pm CDT. This front will
continue moving east tonight. No showers or thunderstorms are
expected with either of these surface features. Relative humidity
values were around 20 percent or just below in parts of far
southwestern ND where the current red flag warning is in effect.
Temperatures were in the mid to upper 80s and should be on the rise
for the rest of the afternoon. The red flag warning remains valid
into the early evening hours.

At upper levels, an upper low was over northern Saskatchewan with a
trough extending south across Saskatchewan. Meanwhile fast zonal
flow aloft was over the Northern Plains states with a series of
minor shortwave impulses moving east across Montana/Wyoming. These
shortwaves will move east across the Dakotas tonight and Sunday.
This will be associated with some scattered showers and isolated
thunderstorms across southwest and south central North Dakota.
Decent 0-6km shear of 40-50 knots, but minimal available CAPE. Thus
severe weather is not anticipated.

The dry air moving into the state today will allow overnight lows to
dip into the upper 40s far northwest, with upper 50s in the far
south central and southeast.

.LONG TERM...(Sunday night through Saturday)
Issued at 330 PM CDT Sat Aug 19 2017

Relatively fast cyclonic flow associated with the upper level
Canadian low will bring more weak upper level impulses across our
region Sunday night and Monday, bringing scattered to isolated
thunderstorms across North Dakota Sunday night and Monday. At this
time it appears that partly to mostly cloudy skies are possible for
the eclipse viewing on Monday, with the best chances of clearer
skies in northwestern North Dakota for late morning and early
afternoon.

The Canadian low moves southeast towards the Great Lakes on Tuesday,
and an upper level ridge builds across the western US Tuesday
through thursday. For the most part the northern plains will remain
on the eastern flank of this ridge maintaining moderate temperatures
in the 70s and mid 80s with low chances for precipitation.

Friday and Saturday look like active weather days with chances of
showers and thunderstorms. The upper ridge breaks down and moves
east as the next upper low moves from southern British Columbia into
the Canadian Prairies, allowing increasing low level moisture riding
up the plains with the help of a southerly low level jet.

&&

.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
Issued at 1223 PM CDT Sat Aug 19 2017

VFR conditions expected through the forecast period.


&&

.FIRE WEATHER...
Issued at 330 PM CDT Sat Aug 19 2017

A surface trough had passed through western North Dakota, with
west winds and drier air moving into the region. The following
cold front had moved into northwestern and far southwestern North
Dakota, with northwest winds gusting to around 30 mph at times.
Dry air continues to push into the region with relative humidity
values of 20 percent or less across most of the warned area. The
red flag warning will remain in effect through the afternoon and
into early evening.

&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 8 PM MDT this evening for NDZ031>033-040-
041-043-044.

&&

$$

SHORT TERM...JV
LONG TERM...JV
AVIATION...JJS
FIRE WEATHER...JV