Area Forecast Discussion
Issued by NWS Aberdeen, SD

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FXUS63 KABR 061140 AAA

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
540 AM CST Wed Dec 6 2017

Issued at 533 AM CST Wed Dec 6 2017

Aviation discussion updated below for 12Z TAFs.


.SHORT TERM...(Today and Tonight)
Issued at 352 AM CST Wed Dec 6 2017

Continue to watch an area of light snow move south-southeast across
western ND, through central SD, then into the central James River
valley. Much of the snow has been on the light side, with only minor
reduction to visibility. Expect this area of snow to gradually shift
south through the first half of the day as the reinforcing shot of
cold air and frontal boundary continue to push things out of the
region. Models show the broad area of weak lift shifting south by
18Z as cold air takes over. Strongest push of cold air will occur
over the next 3 to 6 hours as evidenced by 925mb temps. In fact,
parts of central SD will likely see their high reached this morning,
with falling temps through the morning then steady temps this
afternoon. Breezy northwest winds will be felt across the area
today, with wind chills around 0 degrees over the eastern CWA.

Low temperatures tonight will get rather cold, with readings dipping
into the single digits for most areas. Winds will slacken off,
especially in valley areas, and it does appear skies will try to
clear for most areas.

.LONG TERM...(Thursday through Tuesday)
Issued at 352 AM CST Wed Dec 6 2017

The general longwave pattern remains in place for the next 7 days,
with a ridge over the western CONUS and a trough over the east. The
northern plains remains in more or less northerly flow aloft. This
will allow the arctic front to wobble across the Dakotas/Minnesota.
There is generally good agreement on the 925mb temperature progs
through the weekend and possibly the start next week. We start with
the core of coldest air overhead, with 925mb temperatures between -8
and -14C from west to east. West to northwest flow will erode the
cold air, allowing for temperatures to warm about +8C over the
course of 12 hours. The warm advection will also generate some cloud
cover so this may subdue warming somewhat. The warming trend
continues through the weekend before another surge of colder air
returns to the region Mondayish, with what looks like a glancing
blow from the next cold airmass. It also appears that we are looking
at a dry pattern with the next really minimal opportunity for any
moisture associated with stratus light snow that will come down with
the cold airmass next week.


.AVIATION...(For the 12Z TAFS through 12Z Thursday Morning)
Issued at 533 AM CST Wed Dec 6 2017

KPIR and KMBG will see some -SN and MVFR CIGs through the morning
hours. VSBY may reach MVFR at times as well in areas of more
moderate snowfall. CIGs will trend to VFR by late morning and into
the afternoon, with VFR forecast to prevail through the end of the
TAF period.

Further east over KABR and KATY, generally VFR is expected through
the period. Although, there are some indications that KATY may
have a period of MVFR CIGs this afternoon, although confidence in
this is not too high at this point. For right now, TAF includes a
SCT mention of MVFR, but this may need to be brought to BKN/OVC if
trends further upstream warrant the change.




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