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Area forecast discussion 
National Weather Service Bismarck ND
1234 PM CST Friday Feb 12 2016

issued at 1234 PM CST Friday Feb 12 2016

We let the Wind Chill Advisory for Rolette County expire at noon
CST as observed wind chills are above -25 f at Rolla at 18 UTC. No
significant changes were needed with the midday forecast update as
cold high pressure yields light winds...and sunshine over all but
southwestern ND /where it will be cloudy/ this afternoon.

Update issued at 1001 am CST Friday Feb 12 2016

We added a few flurries into the forecast through the morning over
southwest ND with this update based on observations at Dickinson
and and Hettinger the last hour...and refined sky cover a bit over
the southern James River Valley and south central ND where stratus
between Bismarck and Jamestown is beginning to shrink. The Wind
Chill Advisory continues until 18 UTC for Rolette County with
observed wind chills around -35 f there this morning.

Update issued at 625 am CST Friday Feb 12 2016

Lowered high temperatures a few degrees from the previous forecast
with little to no temperature recovery expected today as Arctic
high pressure builds across North Dakota. Forecast blended to
observed trends through 12 UTC.


Short term...(today and tonight)
issued at 325 am CST Friday Feb 12 2016

Main concerns in the short term include temperatures (and associated
wind chill values) as well as a chance of light snow tonight west
and central...possibly mixed with or changing to freezing rain for a
brief time in the southwest.

Currently...Arctic high pressure was centered over northern
Saskatchewan...with its axis pushing southward into the eastern
Dakotas. Temperatures were already below zero in northeastern North
Dakota...and skies had cleared there as well. Farther south and west
low cloud cover has helped keep temperatures in the 20s above zero
in southwestern North Dakota.

The Arctic high is forecast to continue pushing southeast
today...with the center reaching the Red River valley over Manitoba
and ND/SD/MN. Low temperatures this morning are forecast to be
around 5 to 10 below zero in The Turtle mountains with a north wind
around 10 to 15 miles per hour...resulting in wind chill values of 20 to 30
below zero. A Wind Chill Advisory is currently in effect for Rolette
County until noon today. High temperatures today are expected to
range from around zero in The Turtle mountains and northern James
Valley to the 20s above zero in the far southwest.

Tonight the Arctic high center is forecast to continue sliding
southeast to central Minnesota/Iowa by Saturday morning. As the high
moves southeast...this will allow southerly winds to develop over
the western Dakotas and warm advection along with it. Isentropic
lift aided by h925-h850 southerly winds of 20-30 knots will produce
enough instability for light snow to develop over eastern Montana
Friday afternoon...spreading into the western Dakotas Friday night.
Forecast BUFKIT soundings indicate a temperature profile that favors
light snow mixing with or changing over to freezing rain in the far
southwest - just as the isentropic lift begins to weaken late

Long term...(saturday through thursday)
issued at 325 am CST Friday Feb 12 2016

A wintry mix and accumulating snow Saturday into Sunday highlights
the extended forecast.

The 00 and incoming 06 UTC deterministic and ensemble suites are
in general agreement on a strong shortwave to propagate across
the northern plains Saturday into Sunday. The 00 and 06 UTC
NAM/NAM nest...and 00 UTC GFS/Gem have trended stronger with the
depth of the wave with greater quantitative precipitation forecast...all supported by the 00 UTC
gefs/sref means. However...uncertainty in details remains given
the fluctuation in model solutions over the past 24 hours. At this
time...a wintry mix of freezing rain...sleet and snow is possible
across western North Dakota where a warm layer aloft of +2 to +4 c
is forecast to reside late Saturday morning and through the
afternoon. A change over to all snow is possible by evening as
cold air advection begins to erode the warm layer. Across central
North Dakota...snow is expected to be the dominant precipitation
type. Moderate snowfall accumulations are possible central by
Sunday morning. However...should the stronger trends in the
remainder of the 06 UTC and 12 UTC solutions continue...winter
weather headlines may be needed for both snow and ice potential
across the area.


Aviation...(for the 18z tafs through 18z Saturday afternoon)
issued at 1234 PM CST Friday Feb 12 2016

A few patches of MVFR ceilings may persist in southwest ND this
afternoon...but VFR conditions will prevail elsewhere. We expect
MVFR ceilings to develop from west to east tonight and Saturday
morning...along with a band of light snow as a warm front crosses
the area. There is also a chance of light freezing rain or perhaps
sleet in far western ND late tonight and Saturday morning.


Bis watches/warnings/advisories...


short term...jv
long term...ayd

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