Area Forecast Discussion
Issued by NWS Grand Forks, ND

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FXUS63 KFGF 121007

Area Forecast Discussion
National Weather Service Grand Forks ND
407 AM CST Tue Dec 12 2017

.SHORT TERM...(Today through Wednesday)
Issued at 407 AM CST Tue Dec 12 2017

Main concerns will revolve around the next clipper system tonight
into Wednesday. The potential for freezing rain and then strong
winds will be the main impacts.

Water vapor imagery shows a strong upper wave crashing onshore
across western Canada. The track and strength of this feature is
very similar to the system that affected the region Sunday night
into Monday. The main difference is that the initial band of warm
air advection snowfall is a bit further east, which means the low
level airmass will be warmer across the region. Upper level
forcing (associated with the upper level circulation/jet streak)
will lead to precipitation later this evening and overnight.
Temperatures aloft support liquid across the majority of the
region. Surface temperatures should rise above freezing along and
west of the valley, but remain below freezing east of the valley.
Road temperature forecast supports road surface temperatures
remaining below freezing most areas. Thus, freezing rain potential
exists across the region tonight. Impacts will be dependent on
actual surface temperatures, how quickly road temperatures rise,
and precipitation amounts/coverage. Still some questions, but
will be ramping up the messaging for icing impacts. The next
concern will be strong wind potential following the cold frontal
passage. Strong wind ingredients (mixing, winds aloft, pressure
rise, etc) support wind advisory criteria Wednesday morning into
the early afternoon hours. Any existing snowpack will not be
blowable, but there is the potential for post frontal snow
showers with another upper wave/jet streak quickly following the
initial system (which would occasionally limit visibility).

.LONG TERM...(Thursday through Monday)
Issued at 407 AM CST Tue Dec 12 2017

Will be issued soon.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1142 PM CST Mon Dec 11 2017

As winds turn south-southwest as the high slides east expect an
area of the MVFR/low end VFR spread east
through the fcst area overnight into Tuesday. Clearing of these
clouds expected from the west Tuesday late.




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