Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 151956

Area Forecast Discussion
National Weather Service Bismarck ND
256 PM CDT Thu Mar 15 2018

.SHORT TERM...(This evening through Friday)
Issued at 207 PM CDT Thu Mar 15 2018

Light snow and a wintry mix in the far western counties will be
the main forecast concern for the short term period.

Water vapor imagery depicted a large upper level trough centered
off the coast of Oregon. Embedded shortwaves were moving through
meridional flow over eastern Wyoming and Montana. An associated
surface low was centered over northern Wyoming with a surface high
to the northeast centered over Manitoba. Cloud cover was observed
over the west and south central associated with the active
south/southwest flow. Clear skies were to the north central and

With the upper low almost stationary and flow over Montana
shifting to the northwest, the focus for synoptic forcing was
focused to the west of our border. High-resolution models indicate
a north-south oriented area of precipitation forming this evening
along and west of the Montana/North Dakota border. A few radar
returns were detected over Slope/Billings/Stark counties at the
time of this discussion however there was no evidence of
precipitation reaching the ground. Model soundings for our far
west indicated a persistent 850-700mb dry layer through this
evening, supporting the sporadic chances for precipitation this
evening depicted by high-res guidance. Precipitation that does
reach the ground will have the chance to be any type
rain/snow/sleet given a warm mid-level nose shown by forecast
soundings in the west. The mid-levels cool through the night
switching any light precipitation to all snow through Friday

Through the day Friday a more potent shortwave moves northeast
through Wyoming with associated isentropic lift bringing light
snow to southwest and south-central North Dakota. A rain-snow mix
may be possible in the west where temperatures rise above freezing
in the afternoon hours. East-southeast flow keeps temperatures
mild on Friday with highs in the low to upper 30s.

.LONG TERM...(Friday night through Thursday)
Issued at 207 PM CDT Thu Mar 15 2018

Friday night the aforementioned shortwave lifts north dragging the
associated moisture plume and light snow into northwest North
Dakota before exiting early Saturday morning.

Southwest flow aloft over the Wyoming/Montana sets up after the
previous wave passage, deepening a surface low to our southwest on
Saturday. In the warm sector of the low, southerly flow brings
high temperatures into the upper 30s and low 40s for southwest
North Dakota with low to mid 30s in central and northwest North

The next chance for precipitation arrives with a northerly flow
Canadian low on Sunday. Temperature profiles indicate a rain/snow
wintry mix is possible with this system, however placement,
timing, and amounts of precipitation still has some moderate
disagreement from 12Z model guidance. A blend of guidance brings a
long period of light snow Sunday night through Monday night in the

Ensemble guidance indicates a western ridge building beginning
Tuesday, bringing a gradual warming trend to the area.


.AVIATION...(For the 18Z TAFS through 18Z Friday afternoon)
Issued at 1155 AM CDT Thu Mar 15 2018

VFR conditions are expected through the 18Z TAF period. High
pressure over the Great Lakes Region and low pressure over the
central and northern Rockies will maintain a southeast flow through
the period. Increasing moisture will bring lowering ceilings and
slight precipitation chances into far western ND and eastern
Montana, but should remain west of KDIK and KISN through 18 UTC




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