853
FXUS63 KABR 091920
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
220 PM CDT Thu Oct 9 2025

.KEY MESSAGES...

- Light rain this weekend, mainly for the James River Valley and
eastward. Probability of rainfall of a half of an inch or more
ranges from 30 to 50 percent for this area, highest along and east
of the Sisseton Hills.

- Winds will increase out of the southeast Saturday with gusts of 30
to 40 mph through Sunday before diminishing Sunday night.

&&

.DISCUSSION...
Issued at 215 PM CDT Thu Oct 9 2025

Strong low-level jet and the associated surface gusts continue to
move out of the area ahead of a dry cold front passing this evening,
but some gusts to 30+ miles per hour could continue through this
afternoon over northeastern South Dakota. There may also be
localized fire weather concerns with these winds, particularly on
the eastern side of the Prairie Coteau where winds will be locally
enhanced through downsloping. The moisture advected into the region
over the past couple of days helps keep the area out of any
widespread fire weather concerns. Winds decrease and veer to the
north behind the front, and eventually a surface high pressure
center will build into the region. While low temperatures are
expected to remain in the low 40s to perhaps upper 30s, the presence
of the high pressure center, light winds, and clear skies may
provide an opportunity for isolated pockets of frost and/or fog to
form. Best chances for frost will be in western Corson county, and
is most likely on the western edge of the Prairie Coteau. Confidence
is low for both however, and only a weak signal is present for both
phenomena in model guidance.

Focus then shifts to this weekend, when models remain supportive of
the upper-level trough sitting over the western CONUS developing a
low pressure center to the west of the CWA. This low will proceed to
travel into North Dakota and southern Canada, dragging a cold front
across the Aberdeen forecast area. Precipitation will occur as a
result, mainly expected out ahead of the front Saturday night into
Sunday supported by a 50 knot low-level jet. Main impact areas for
this system are areas east of the James River Valley, with
accumulation along and west of the river generally expected to be
less than a quarter of an inch through the event. East of the James
there is still somewhat of a large spread in the accumulation
totals, with the latest NBM run showing a 25th/75th percentile range
of 0.1" to 1" through Sunday evening. A near-median QPF has been put
in today, peaking between 0.4"-0.5" in west central Minnesota, and
ensembles give a 30-50% chance to exceed 0.5" of rain in those
areas.

The low-level jet mentioned above will also bring the return
of strong southerly wind gusts both Saturday and Sunday. Peak winds
will be in the afternoon as heating will allow for a well-mixed
boundary layer to bring gusts from the jet down to the surface.
Sustained wind speeds will border on Wind Advisory criteria, but
chances still appear fairly marginal at this point. Latest ensemble
guidance highlights a 10-30% chance of wind speeds to 30 miles per
hour or greater over central and north central South Dakota both
Saturday and Sunday afternoon, with isolated pockets of chances up
to 40%. These isolated pockets seem to support the idea that at
least based on the current forecast, localized areas will get above
criteria, but it may not be widespread enough to warrant a headline.
Gusts tell a similar story, with low probability to hit criteria (45
miles per hour) at a widespread level, but isolated pockets may see
that threshold met.


&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1219 PM CDT Thu Oct 9 2025

Terminals KABR,KATY,KPIR,KMBG

Currently (~17Z) monitoring a low cloud deck moving over
northwestern South Dakota and western Minnesota this afternoon with
ceilings that, for the moment, are remaining just above MVFR status.
Outside of this cloud deck that is expected to move out of the area
this afternoon, VFR conditions are expected through the TAF period.
The main aviation concern is still the strong southerly winds over
northeastern South Dakota this afternoon. Gusts up to 30 miles per
hour have stuck around slightly longer than anticipated this morning
over the James River area, but winds have begun to decrease, a trend
that will continue over the next couple of hours. Dry cold front
will continue its progression this afternoon, pushing the strong
winds out of the area by this evening. Winds then turn northerly
behind the front, with gusts topping out at 10-15 knots. There is a
slight signal for fog on the west side of the Prairie Coteau this
morning, but confidence is low and winds will likely be high enough
to where significant drops in visibility due to fog development is
unlikely.


&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&

$$

DISCUSSION...BC
AVIATION...BC