Area Forecast Discussion
Issued by NWS Aberdeen, SD
FXUS63 KABR 021702 AAA
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1102 AM CST Fri Dec 2 2016
Issued at 1102 AM CST Fri Dec 2 2016
Weak shear axis/short wave trough helping to bring some flurries
to the region this morning. Radars showing some weak returns along
with a few obs showing some light snow flurries. Thus, have
included flurries into the afternoon. Otherwise, it will remain
cloudy with only a few degrees rise in temperatures.
UPDATE Issued at 559 AM CST Fri Dec 2 2016
See below for an aviation forecast discussion for the 12Z TAFs.
.SHORT TERM...(Today through Sunday)
Issued at 400 AM CST Fri Dec 2 2016
Stratus remains, but as winds shift to the southwest this evening,
gradual clearing will move in from the southwest. It might take some
time to cross the entirety of the CWA however, with the last of the
stratus lingering in western Minnesota into the late morning
Saturday. This is in advance of milder air ahead of a weak wave
that moves through late Saturday. There will be a band of warm
advection mid clouds, but with a dry/warming subcloud layer the
low pops Saturday are more than likely to be just some flurries.
There may also be some Coteau downslope winds under this regime
Saturday night, ahead of a north south oriented surface trough with a
surface low moving across southern Canada. Winds in the warm
advection layer only top out around 30kts so winds will be well
below advisory criteria. Favorable mixing winds behind this feature
will result in continued mild conditions for Sunday.
.LONG TERM...(Monday through Thursday)
Issued at 400 AM CST Fri Dec 2 2016
Things that should continue to be monitored in the out periods
include surface low/cold front timing into Monday/Monday night and
any precip chances associated with the system that lifts enewd
across the Dakotas on Monday, along with strength of winds/cold air
and their resulting wind chill values, especially from Tuesday
through Thursday night.
It looks like Sunday night is the warmest period in the forecast
next week. 00Z GFS/ECMWF solutions are much similar in timing the
surface low/onset of low level caa into the cwa during the day on
Monday placing the surface cold front over the far
eastern/southeastern forecast zones by the end of the day on Monday.
The 00Z Canadian remains a bit slower (by appx 6 to 12 hours) than
the other two deterministic GSM`s timing of this feature, but does
bring in the same strength of low level cold air as the GFS/ECMWF by
mid-week. As for precipitation chances heading into Monday, all
three models continue to trend the vast majority of precipitation
coverage/chances north of this cwa when the early week low pressure
system works out of the Rockies and moves over the region.
That said, if precipitation does develop over this cwa Monday into
Monday night, currently, it is likely being confined to along and
north of a line from Eagle Butte, SD to Ortonville, MN.
Timing/Coverage of precip is a big deal because the GFS/ECMWF prog
some breezy/windy conditions to spread from west to east across
SoDak during the day Monday and on into western MN Monday evening.
And, typically, round these parts combining falling snow with
breezy/windy conditions tends to create the potential for hazardous
The mid-week system is currently progged to work out of the Rockies
and traverse the central plains states, remaining south of this CWA.
But, it appears that one thing that doesn`t miss this region is the
potential for some areas to see wind chill values falling below 20
below zero by Wednesday night of next week. Models maintain a
notable pressure gradient and west-northwesterly mixing wind
throughout the week next week while below normal cold air is over
the forecast area, and Superblend guidance this morning actually
didn`t do too bad a job capturing 13 to 17 knot winds in the wind
grids. Will continue to monitor precip potential right at the tail
end of the period and just beyond, as there appears to be some
potential for one or more clipper-type low pressure systems to work
through the region (latest 8 to 14 day Temp/Precip outlook
highlights much below normal temperature potential and above normal
.AVIATION...(For the 12Z TAFS through 12Z Saturday Morning)
Issued at 559 AM CST Fri Dec 2 2016
A persistent low overcast event is ongoing over this forecast
area, including all four terminals. Radar, observations and road
reports indicate there are areas of freezing drizzle and/or
flurries falling out of these clouds this morning as well.
Short range guidance suggests the western edge of these clouds
may erode/dissipate with daytime heating/mixing. KPIR and possibly
KMBG could see some clearing by early evening. But if that`s the
case, those two terminals could be facing sub-vfr visbies in fog
by late tonight, given the amount of available surface/boundary
layer moisture, light winds and clear sky expected to be around.