Area Forecast Discussion
Issued by NWS Aberdeen, SD
FXUS63 KABR 300201 AAB
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
801 PM CST Tue Nov 29 2016
Issued at 755 PM CST Tue Nov 29 2016
Recent radar/sat pic loops suggest that best chance for
accumulating snow/blowing snow will be over the western CWA, or
along the MO valley as a s/w rotates south over the region. Vsby
occasionally getting down to 1/2 mile or less remains possible
although ASOS at KMBG/KPIR have generally been a mile or more.
Headlines appear appropriate out west. In the east it`s a bit more
confounding. Really haven`t seen much snow accumulation this
evening, but CAMS continue to show the potential for some up slow
snowfall enhancement on west edge of the Glacial Lakes region, so
will maintain headline for now.
.SHORT TERM...(This Evening through Wednesday)
Issued at 351 PM CST Tue Nov 29 2016
Forecast challenges tonight and Wednesday continue to swirl around
snow timing/coverage and amounts while strong northwest winds
persist over central and north central South Dakota.
Currently, under a cloudy sky and northwest winds, temperatures are
hovering anywhere from a few degrees below freezing to as much as 5
or 6 degrees above freezing. Northwest winds across the far eastern
forecast zones are just beginning to switch around to the northwest
around 10 to 15 mph. To the west over the Missouri River valley,
northwest winds of 20 to 40 mph with gusts to 50 mph are ongoing.
And, bands of snow continue to march around this parent upper level
low pressure circulation centered on central MN. Have also been
receiving reports today of near blizzard conditions in very poor
visibility and falling snow over portions of central and north
central South Dakota whenever an area of snow would move through.
Outside of the falling snow, visibility and blowing snow is not so
much an issue. Snow accumulations from last night through this
afternoon have varied anywhere from a trace to as much as 4 inches.
More of these very same conditions (occasional near blizzard) will
persist right into tonight/early Wednesday across the Missouri River
valley region as the next large batch of snow over North Dakota is
starting to enter into north central South Dakota. Further east in
the CWA over onto the prairie coteau and into west central MN, there
are additional s/w`s rotating north and west out of the western
Great Lakes region that are expected to produce their own additional
areas of falling snow from now through Wednesday afternoon. In fact,
with northwest winds of 15 to 30 mph with higher gusts expected to
persist over the eastern forecast area tonight and Wednesday, the
western slope and western half of the prairie coteau is expected to
see some locally enhanced snowfall. The SPC SSEO, NCAR 3km Ensemble
and ABRWRF 4km solutions all support this idea of locally enhanced
snowfall amounts on the coteau (to as much as 5 to 8 inches of snow)
while surrounding James River and Red River valley regions may only
see 24 hour snow accums of 1 to 3 inches.
Winter Weather Advisory continues (added Clark county) through the
first half of Wednesday across central/north central SoDak and
carries the strongest "near blizzard" wording, while northeast SoDak
maintains wording suggestive of slightly better visbies/conditions
in breezy winds and falling snow through Wednesday afternoon.
Will watch minimal changes in low level thermal advection yield
perhaps 3 to 6 degree cooler lows tonight and highs on Wednesday,
compared to last night`s lows and today`s highs.
.LONG TERM...(Wednesday Night through Tuesday) Issued at 351 PM
CST Tue Nov 29 2016
The low pressure that has been over the region the past couple days
will continue to move away from the area Wednesday night. On its
backside though, expect lingering light snow showers with minimal
accumulations. The rest of the forecast is mainly a dry one with
just some small chances for light snow Thursday night as the GFS
shows a weak backdoor cold front sliding south along with some upper
level shortwave energy.
Concerning temperatures, there was a collaborative effort to raise
MinT`s Wednesday night and Thursday night as there will likely still
be quite a bit of cloud cover across the region. SuperBlend temps
seemed a bit too cool given the expected cloud cover, so raised
temps a few degrees, more towards BCCONSRaw - or whatever set of
warmer guidance numbers. Overall, temps throughout the extended
period look to be near normal. Will be watching trends closely as we
head into Tuesday and Wednesday of next week in what appears to be a
change to much colder temperatures across the Northern Plains.
.AVIATION...(For the 00Z TAFS through 00Z Wednesday Evening)
Issued at 527 PM CST Tue Nov 29 2016
Light snow will continue to rotate south over the region through
the night, with occasional ifr vsbys and cigs, especially at
KMBG/KPIR. KATY/KABR should experience less ifr conditions are
more mvfr conditions through the night.
SD...Winter Weather Advisory until noon CST /11 AM MST/ Wednesday for
Winter Weather Advisory until 6 PM CST Wednesday for SDZ006-007-