Area Forecast Discussion
Issued by NWS Bismarck, ND

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FXUS63 KBIS 210623

Area Forecast Discussion
National Weather Service Bismarck ND
123 AM CDT Sat Oct 21 2017


Issued at 123 AM CDT Sat Oct 21 2017

Strong pressure rises over western ND continue to spread east into
my central counties. Models water down the pressure rises as the
front continues east now through 12Z, though think even my eastern
areas will see an uptick in winds by sunrise if models are correct
so upped winds over my east a bit. Otherwise the inherited wind
grids have captured things rather well early this morning. Will
maintain wind headlines as is despite wind gusting briefly outside
of the advisory to 45 MPH. Outside of the higher terrain of the
southwest, we do not expect winds to last much longer than an hour
or two so went with a special weather statement to cover this
brief surge in winds associated with the pressure rise bubble west
and central.

UPDATE Issued at 935 PM CDT Fri Oct 20 2017

Not too much to change. Current winds gusting as high as 55 mph in
a rain shower at Miles City Montana this past hour. Passage of
the cold front, pressure rise, and shower mixing the winds. Will
leave winds in the wind advisory area 30 to 45 mph for now but a
few higher gusts are possible to 50 mph. Otherwise current
forecast ok.

UPDATE Issued at 632 PM CDT Fri Oct 20 2017

At 6 PM CDT a cold front extended across eastern Montana and will
move into western North Dakota this evening. A wind shift to the
northwest will accompany the front by mid evening. Southwest
North Dakota still appears to be the best place for gusty winds
this associated with the pressure rise behind the front as well as
the gradient winds later this evening. Current forecast looks


.SHORT TERM...(This evening through Saturday)
Issued at 342 PM CDT Fri Oct 20 2017

Strong winds expected tonight through Saturday.

Tonight, an upper level trough begins an eastward progression across
the Northern Plains. A strong associated cold front will move
east ahead of the upper trough into western North Dakota tonight,
then into central ND by 06Z Saturday. Strong cold air advection
and strong winds are expected with this system. A strong pressure
rise bubble, with a 3-HR rise max of 10MB, is advertised by the
12Z GFS/NAM to enter southwest ND between 02-04Z. The pressure
rise bubble decreases in intensity as it moves into central ND.
BUFKIT soundings are indicating peak winds at the top of the mixed
layer around 45kts in the southwest and around 30kts in central
and eastern areas of the CWA. Momentum transfer is expected,
especially in the west, as phasing between surface and 850mb winds
is expected; highlighted well within the 12Z model suite.
Although uncertainly remains as to how much energy will transfer
to the surface, there is enough confidence to issue a Wind
Advisory for the southwest.

A Wind Advisory has been issued for Southwest North Dakota
from Friday 9 PM (MDT) through Saturday 6 PM (MDT).

.LONG TERM...(Saturday night through Friday)
Issued at 342 PM CDT Fri Oct 20 2017

Progressive flow aloft is projected for the long term.

A series of upper level troughs are forecast to move across the
Northern Plains through the extended. Chances for precipitation will
accompany each disturbance though overall chances look
underwhelming. Wind will be the bigger impact with each system.
Breezy/windy conditions are expected to persist throughout the long
term. Monday has the potential for strong winds, as another surface
front is expected to move across the area.

Wednesday night-Thursday the 12Z GFS/ECMWF push a strong cold front
across the state. Another strong wind event looks to unfold if
models stay their present course. -4 to -10C 850mb temperatures are
also advertised for Thursday to advect into the area on the backside
of this potential front. Though the timing of the front remains
questionable, below average temperatures are forecast for the latter
days of the period.


.AVIATION...(For the 06Z TAFS through 06Z Saturday night)

Issued at 123 AM CDT Sat Oct 21 2017

Hazards to aviation include gusty northwest winds and low level
wind shear as a strong cold front sweeps through the region. VFR
conditions will prevail through the 00Z TAF period. The cold front
had already reached KISN, KDIK, KHEI with west winds gusting to
around 30-40 knots. KISN ASOS has power issues. Observations being
taken by a contract observer Friday evening, but not expected to
continue overnight. NOTAM issued and amendments to the KISN TAF are
not planned.


Wind Advisory until 6 PM MDT this evening for NDZ031>033-040-041-



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