Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 151227

Area Forecast Discussion
National Weather Service Bismarck ND
627 AM CST Thu Feb 15 2018

Issued at 623 AM CST Thu Feb 15 2018

Quick update for observed trends through 12 UTC. Falling
temperatures are expected through the day as cold high pressure
builds across western and central North Dakota.


.SHORT TERM...(Today and tonight)
Issued at 331 AM CST Thu Feb 15 2018

Currently, an upper level longwave trough extended from the Hudson
Bay Low southwestward across the Canadian prairies to the Desert
Southwest. Meanwhile at the surface, an arctic cold front extended
from a surface low over Lake Superior westward across Minnesota and
along the border of ND/SD, with the center of the arctic high over
Alberta. Widespread light snow continued along the upper level
trough and mainly along and north of the surface cold front.

The upper level longwave trough is forecast to move southeast across
the Northern Plains today and tonight. As this occurs, the arctic
high is forecast to move south into eastern Montana/western Dakotas
this afternoon, and continue its path southeastward into the central
Plains by daybreak Friday morning. The strongest upper level
shortwave impulse within the longwave trough was over
Montana/Wyoming this morning, and should move into South Dakota this
afternoon. This is where the best forcing occurs today, and where
the most snowfall is expected. The snowfall intensity was the
greatest early this morning over Montana, and this should shift into
northern Wyoming and South Dakota during the day. The northern
extent of the better forcing will clip southwestern North Dakota
this morning.

For western and central ND: Early this morning, the snow has mostly
ended across the far north central, but light snow continued west
and the southern 2/3 of the state. We expect light snow to end from
north to south across central ND, but continue in southwestern North
Dakota through the remainder of this morning. Snow should taper off
in the far southwest corner of the state this afternoon.

Decreasing clouds from north to south today, with clear skies
tonight as the arctic high moves in. Falling temperatures through
the day today, with overnight lows tonight from around zero to 5
below. Low temps tonight will need to be re-evaluated, depending on
temperature trends and later model runs. Those temps may need to be

.LONG TERM...(Friday through Wednesday)
Issued at 331 AM CST Thu Feb 15 2018

The established upper level Hudson Bay Low will keep a general
cyclonic flow aloft over the Northern Plains through the long term.

A minor shortwave in the flow aloft clips southwestern ND Friday
night, bringing a chance of light snow to this area.

A more potent shortwave moves into the Pacific Northwest on
Saturday, and moves across the Rockies and Dakotas Saturday night
and Sunday before exiting to Minnesota. In response, a surface low
develops over Wyoming/Colorado/South Dakota, and sets up an area of
precipitation in the form of light snow across Montana/North Dakota
Saturday night...and North Dakota and Minnesota on Sunday. As of
now, the global model consensus favors southern North Dakota for an
inch or two of snow during this period.

An upper level trough becomes established over the Rockies next
week, keeping chances of light snow over much of the US. At this
time it appears that most of the precipitation with this system
would be south of our area, but this also sets up a period of below
average temperatures with highs in the single digits above zero and
lows from 5 to 15 below zero.


.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 623 AM CST Thu Feb 15 2018

Widespread MVFR ceilings across western and central North Dakota
this morning with IFR visibility across the southwest and far
south central in light snow. Snow will slowly diminish through the
morning and into the afternoon. Skies will clear late this morning
and through the afternoon from north to south.




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