Area Forecast Discussion
Issued by NWS Aberdeen, SD

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS63 KABR 181906

Area Forecast Discussion
National Weather Service Aberdeen SD
106 PM CST Mon Dec 18 2017

.SHORT TERM...(This Evening through Tuesday Afternoon)
Issued at 105 PM CST Mon Dec 18 2017

Have been seeing an abundance of mid-high clouds streaming overhead
on the nose of an upper jet stretching southeast from British
Columbia. These clouds have tried to limit some of the mixing so far
today, but still seeing some stronger wind gusts in the downslope
region of the Coteau near Peever/Sisseton. Gusts earlier today
reached the upper 30s mph and have been fairly steady over the last
hour around 30mph.  Expect those gusty winds (up to 40 mph) to
continue into the early evening hours until the cold front currently
located near the Canadian/Montana border sweeps through.  Ahead of
that cold front, we`re likely seeing the warmest day for the rest of
2017 and temperatures have warmed into the 40s by 1pm for most of
the area.

The cold front will continue to slide to the southeast and across
the area this evening, shifting winds around to the northwest.
Models still showing brief hints of gusty winds behind the front (20-
30kts) for an hour or two, otherwise winds will gradually diminish
through the night. Think the frontal passage will largely be a dry
one, but there have been a few models showing light QPF as it moves
through during the evening hours. Contemplated adding a brief
period of sprinkles/flurries (llvl thermal profile is on the edge
of rain/snow) to account for that idea from hi-res models, but the
coverage/chances look to be fairly low.

A high pressure ridge will quickly move over the area tomorrow
morning before sliding to the east and into MN by evening. This will
lead to a sunny start to the day for much of the area. Moisture
spilling southeast from the developing low in the Northern Rockies
will lead to mid-high clouds over western SD and expect that to lift
northeast through the day. Behind this evenings cold front, highs
tomorrow will be around 10 degrees cooler than today, but still well
above normal for this time of year.

.LONG TERM...(Tuesday through Sunday)
Issued at 359 AM CST Mon Dec 18 2017

Upper level northwest flow will become more zonal by midweek ahead
of an approaching shortwave trough. This wave will move through late
Wednesday night into the day Thursday. Another wave then moves in
and broadens out to encompass the majority of the country. At the
surface, high pressure will keep conditions dry Tuesday and Tuesday
night. Attention then turns to an approaching low pressure system
that continues to look like the next potential significant weather
maker. The low looks to drop from Montana across eastern Wyoming and
across the Central Plains, bringing the best chance for snow to the
area late Wednesday night through Thursday evening. Models continue
to differ some on the exact timing of the precipitation, but do seem
to agree that the southern CWA will be the focus for somewhat higher
amounts during the day Thursday. Windy conditions are possible on
Wednesday ahead of the system, then again late Wednesday night and
Thursday in conjunction with the falling snow on the back side of
the system. Current indications are for less than an inch across the
north, to 3-4 inches across the south, but for the more significant
issue being the winds occurring with the falling snow. Visibilities
will likely be reduced at times across the CWA. The remainder of the
period will be mostly dry, with much colder air filtering into the
region under high pressure and in association with the strong upper

Tuesday and Wednesday will see a continuation of mild temperatures,
with highs in the 30s and 40s. The cooler air then moves in, with
highs mainly in the teens Thursday through the weekend.


.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1124 AM CST Mon Dec 18 2017

VFR conditions will prevail through the TAF period. Gusty west to
southwest winds today will shift to the northwest behind a cold
front this evening. Then high pressure will move into the area,
weakening winds and bringing a brief period of decreasing clouds.
Tomorrow, mid-high clouds will increase from the west ahead of
the next system to affect the area around mid week.




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