Area Forecast Discussion
Issued by NWS Bismarck, ND

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000
FXUS63 KBIS 191826
AFDBIS

Area Forecast Discussion
National Weather Service Bismarck ND
1226 PM CST Mon Feb 19 2018

.UPDATE...

Issued at 1225 PM CST Mon Feb 19 2018

Snow developing southwest as scheduled. Made a few tweaks to POPs
otherwise no major changes in the near term period.


UPDATE
Issued at 1005 AM CST Mon Feb 19 2018

Adjusted POPs based on latest radar and near term trends. This
resulted in pushing back the timing a bit. Also increased POPs
later today and tonight when snow will expand north and east
across western and central ND. This is again based on latest model
output. Other changes were minimal with this update.

UPDATE Issued at 732 AM CST Mon Feb 19 2018

Extended the Winter Weather Advisory across southwest North Dakota
through 06 UTC tonight. The 06 UTC GFS/NAM, 09 UTC SREF, and the
12 UTC HRRR/RAP all continue accumulating snow southwest this
evening with the arrival of a series of impulses propagating out
of the intermountain west longwave trough.

&&

.SHORT TERM...(Today and tonight)
Issued at 254 AM CST Mon Feb 19 2018

Accumulating snowfall across southwestern and south central North
Dakota highlights the short term forecast.

A trough over the western CONUS continues to dig south as it
propagates east towards the region. An initial upper level
shortwave ejected from the trough was noted on water vapor
satellite imagery. This wave has been producing light snow over
parts of southwestern and south central North Dakota. Expect 1 to
3 inches with 5 inches possible locally in some of these areas.

Another stronger wave will eject later this afternoon and spread
snow further east and north through the day. Accumulating snow
associated with this upper level feature will be maximized over
the southern James River Valley, where 2 to 4 inches can be
expected with totals up 6 inches possible locally. Totals will
drop off quickly to the north, but aerial extent of the snow may
reach all the way up into the Turtle Mountains. Will be issuing
another winter weather advisory for my far south central and the
southern James River Valley with this package.

Finally, breezy winds over the James River Valley tomorrow will
promote the potential for some patchy blowing snow, reducing
visibilities, especially in open country. Colder temperatures
overspread the region Monday night as surface high pressure slides
in. Dangerous wind chills will be possible overnight, especially
across the west.

.LONG TERM...(Tuesday through Sunday)
Issued at 254 AM CST Mon Feb 19 2018

Arctic air will be in place on Tuesday as much of the forecast
area will struggle to rise above single digits for highs. Tuesday
night and Wednesday morning will see widespread lows in the
double digits below zero. Dangerous wind chills, as low as 30
below zero, are likely across all of western and central North
Dakota.

Late Tuesday through the end of the work week, the upper level
trough weakens and merges with the already established Hudson Bay
Low, keeping cyclonic flow aloft over North Dakota. This flow
pattern will keep the forecast area generally in a below average
temperature regime with some slight chances of light snow off and
on throughout the week. A slight warmup is possible by the end of
the work week.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 1139 AM CST Mon Feb 19 2018

Snow had begun at Hettinger in far southwest ND with MVFR vsbys but
lower VFR cigs. VFR at all TAF sites at 18z today, but snow with
MVFR cigs and vsbys expected to develop across southwestern ND at
KDIK early this afternoon, then spread north and east into KISN/KBIS
by late afternoon, and reaching KMOT aft 00z and KJMS aft 06z.
Conditions becoming IFR mainly at southern TAF sites of KDIK/KBIS
mainly aft 00z and at KJMS aft 06z. Improving conditions to VFR late
Tuesday morning and into the afternoon.


&&

.BIS WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 9 AM CST /8 AM MST/ Tuesday for
NDZ045>048-050-051.

Winter Weather Advisory until 11 PM MST this evening for NDZ040-
043-044.

&&

$$

UPDATE...NH
SHORT TERM...ZH
LONG TERM...ZH
AVIATION...JV



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