Area Forecast Discussion
Issued by NWS Aberdeen, SD

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FXUS63 KABR 151127 AAA

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
527 AM CST Fri Dec 15 2017

Issued at 523 AM CST Fri Dec 15 2017

See updated aviation discussion below.


.SHORT TERM...(Today and Tonight)
Issued at 208 AM CST Fri Dec 15 2017

Northwest flow continues aloft today before beginning to flatten
out and bring slight ridging in at 500mb as the trough off the
Pacific Coast moves onshore this afternoon and stretch from
Saskatchewan through western MT through central CA by daybreak
Saturday. At the sfc, this period will be marked by low pressure
over the Canadian Northwest Territories pushing into ND this
evening and sinking across the eastern Dakotas and western MN
overnight, as the parent low moves into northern Saskatchewan. The
best chance of precipitation will stay to our north and northwest.
However, very light precipitation can`t be completely ruled out.

Temperatures will remain near or below freezing through 17Z, causing
issues in type if precipitation exists. Our eastern counties and
northern border with ND will not only see the best chance of
precipitation, but is the location of less confidence in mode.
Soundings continue to show limited ice production, giving to a
potential for freezing drizzle. Light freezing drizzle on the back
end of the snow has been reported as late as 07Z east of ABR.

Otherwise, temperatures will rebound into the mid 30s to upper 40s,.
A few low 50 degree readings will be possible west of the Missouri
River. Fire weather conditions will be elevated west of the Missouri
River, as these temperatures of 10 to near 20 degrees above normal
combine with relative humidity values in the 30 percent range west
of the Missouri River. on a positive note, winds should stay around
or less than 15 mph.

Next chance of precip could come in Saturday afternoon over our
western counties. Most operational runs do indicate some light
precip in our area, with the better chance staying to our southwest
Saturday night. Will keep much of our area in the slight chance
range. Dry weather should be the rule Sunday. Weekend highs should
be in the upper 30s to low 40s, with relatively light winds

.LONG TERM...(Saturday through Thursday)
Issued at 208 AM CST Fri Dec 15 2017

The early part of the extended period starts off with an upper level
trough sliding across the region Sunday night through the day
Tuesday. Weak ridging then sets up until a fairly deep trough
approaches and tracks across the Plains on Thursday.

The majority of the period will be dry, beginning with high pressure
over the region Sunday night. A frontal boundary looks to track
across the area Monday afternoon and evening, but the better
moisture and mid level dynamics look to stay to the north of the
CWA, so at this time, expect the front to move through dry. High
pressure then settles in once again until a low pressure system
approaches from the west/northwest and looks to bring a decent
chance of snow to the area on Thursday. Current model runs are in
decent agreement, with the system not producing huge amounts of
snow, but that strong winds will occur in conjunction with the snow.
With this system still being six days away, will stick with the in-
house model blend POPs and continue to monitor.

Temperatures will remain mild through the majority of the period,
with highs in the 30s and 40s Monday, Tuesday and Wednesday. Will
then see a big change in temperatures beginning Wednesday night as
colder air filters into the region. Lows on Wednesday night will
drop into the lower to mid teens, with highs only in the upper teens
and 20s on Thursday.


.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 523 AM CST Fri Dec 15 2017

An area of MVFR cigs will drift across the far eastern CWA through
the mid morning hours, along with the potential for some light
snow or light freezing drizzle. At this time, the precipitation
is not expected to affect any of the TAF sites. Otherwise, VFR
conditions will prevail across the area today and tonight.




LONG TERM...Parkin
AVIATION...Parkin is the U.S. government's official web portal to all federal, state and local government web resources and services.