Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 200632

Area Forecast Discussion
National Weather Service Bismarck ND
1232 AM CST Mon Nov 20 2017

Issued at 1231 AM CST Mon Nov 20 2017

Warm advection has begun in the west with southwesterly surface winds
around 10 to 15 mph with the approach of the next clipper system.
The clipper low was over southwestern Saskatchewan at midnight, and
is expected to move southeast across south central Canada on Monday.
Temperatures remain steady or were rising a bit into the mid and
upper 30s southwest. Meanwhile temperatures were in the 20-30F range
over much of central ND. We expect southwest winds to develop/expand
eastward into central ND overnight, with temperatures in the upper
20s/lower 30s by sunrise in eastern portions of central ND. Only
minor changes to previous forecast for hourly temperature trend and

UPDATE Issued at 932 PM CST Sun Nov 19 2017

Areas of patchy fog have developed over northeast ND. As of yet
nothing in the Turtle mountains area, but current dewpoint
depressions are nil. Previous forecast had a mention of patchy fog
tonight until southwest flow increases behind warm front that
moves through around 09 UTC, and this still looks reasonable.
Temperatures quite a bit warmer tonight with the warm front and
increasing high clouds. Did bump up sky cover with the increase in
high level cloudiness.

UPDATE Issued at 541 PM CST Sun Nov 19 2017

Bumped up sky cover a little with quite a bit of high thin
cloudiness over the region this evening. Otherwise no significant
changes to the going forecast.


.SHORT TERM...(This evening through Tuesday)
Issued at 458 PM CST Sun Nov 19 2017

Quiet and mild weather will continue through the night as a surface
warm front continues to loiter in north central/northeast areas of
ND. Southwesterly surface winds will also assist in advecting warm
air into western and central ND, keeping overnight lows above

Monday, mild conditions will continue and northwest winds will
become strong as a clipper scoots east across southern Canada. Winds
will increase through the morning and gradually taper off from west-
to-east through Tuesday. The strongest winds are expected overnight
Monday in north central areas into the upper James River Valley. 12Z
BUFKIT soundings are indicating peak winds at the top of the mixed
layer around 50kts. Momentum transfer is likely as strong cold air
advection and steep low-level lapse rates of around 7.5C/Km will
accompany this system. A Wind Advisory may be possible.
Precipitation accompanying this system is favored by the 12Z model
suite to stay north and east of the CWA. Although the GFS is placing
light QPE over the north central. A few flakes early Tuesday
morning, on the back side of the clipper, wouldn`t be surprising.
Tuesday, high pressure slides southeast into ND behind the clipper.
Cold Arctic air will tag along resulting in below average
temperatures through Tuesday. Very cold conditions early Tuesday
morning with wind chill values across the north round -15 degrees.

.LONG TERM...(Wednesday through Sunday)
Issued at 458 PM CST Sun Nov 19 2017

Holiday travel impacts are possible Wednesday as confidence
increases for a wintry mix of precipitation across northwest and
central ND.

Ensemble and deterministic models are providing good agreement on
ridging building into the Plains Wednesday. At the surface, low
pressure will advance across the area bringing chances for
precipitation. A wintry mix of rain, snow, sleet, and freezing rain
will be possible as a baroclinic zone over ND creates a northeast-to-
southwest temperature gradient. Early Wednesday morning a period of
freezing rain or sleet is possible in northwest areas. Chances for
freezing precipitation will shift east through the morning and
afternoon. The likelihood of slick roads Wednesday are increasing as
models become more aligned.

Weather for Thanksgiving looks fairly quiet. Thereafter a slightly
unsettled pattern sets up with occasional disturbances moving
through the region resulting in precipitation chances Friday.


.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1231 AM CST Mon Nov 20 2017

VFR conditions expected through the 06Z TAF period. High clouds
tonight and Monday morning with low pressure to our north. Light
south to southwest winds expected. A cold front moves through Monday
afternoon with winds shifting west to northwest and becoming gusty.
Decided to add LLWS late tonight into Monday morning for KISN and
KMOT due to light surface winds and increasing westerly winds aloft.




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