Hail and Damaging Winds in South Dakota, August 28, 2021

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1224 AM CDT Sat Aug 28 2021

.UPDATE...
Issued at 1223 AM CDT Sat Aug 28 2021

Updated for 06Z TAF discussion.

UPDATE Issued at 924 PM CDT Fri Aug 27 2021

No major changes made to the forecast this evening. Have seen an
area of light precipitation move over the northwestern CWA this
evening, and most of the CAMs continue to indicate the potential
for thunderstorm development in that same area during the
overnight hours, with the storms then spreading eastward.
Therefore, did make a few adjustments to POPs this evening, but
none after about 06Z. No changes made to winds or temperatures at
this time.

&&

.SHORT TERM...(This Evening through Saturday Night)
Issued at 252 PM CDT Fri Aug 27 2021

More showers and thunderstorms expected for the short range. S/W
trof evident in sat pix over MT will slide east into the western
Dakotas tonight. Increasing moisture and instability per
forecast HREF MUCAPES is expected ahead of this feature, transported
by light to moderate LLJ development across the High Plains this
evening. Meanwhile, mid-level winds will be increasing as H5 trof
approaches tonight. So, there will be fair amount of shear and
instability to work with in producing thunderstorms overnight, some
probably severe. However, curiously, latest CAMS have backed off on
coverage of storms overnight. Nonetheless will maintain overnight
POPs but limit to less than likely given latest hi-res model
output.

On Saturday a synoptic scale cold front will be pushing across the
CWA, and should be near the eastern border with MN by late
afternoon/early evening. This area is where we'll have the highest
chances for convection and even severe weather. Any storms that form
in eastern SD should move off into MN relatively quickly early in
the evening. Saturday night looks mild and relatively calm once
early storms push out of the forecast area. Overall, temperatures
should favor near to slightly below normal for the period.

.LONG TERM...(Sunday through Friday)
Issued at 252 PM CDT Fri Aug 27 2021

An upper trough axis will be pushing east and exiting our area by
the time this period gets underway Sunday morning. Sfc high pressure
will be overspreading the CWA which will give us dry conditions and
mild temps. This high will slip off to the east-southeast as the new
work begins on Monday and our area gets back into return flow and
richer low-level moisture. An upper ridge will build in across the
northern High Plains at the same time with perhaps some weaker s/w
energy sliding down the front-side into the Dakotas. This may
promote an uptick in pcpn chances Monday into Monday night. This
upper ridge is progged to amplify over our region going into the
middle of next week. Thereafter, models prog a southwesterly flow
pattern to resume across the region. This will be conducive to
seeing passing shortwave energy rotate through the area. Combined
with sfc disturbances and/or passing frontal boundaries, our
forecast area will continue to see additional pcpn chances through
the end of the work week.

&&

.AVIATION...(For the 06Z TAFS through 06Z Saturday Night)
Issued at 1223 AM CDT Sat Aug 28 2021

Terminals KABR,KATY,KPIR,KMBG

For the most part, VFR conditions will prevail across the area
tonight and through the day Saturday, with the exception of the
potential for some IFR/MVFR cigs across the east during the day
Saturday, including at KATY and KABR. Scattered showers and
thunderstorms are possible late tonight and Saturday, with periods
of MVFR cigs and vsbys expected with the thunderstorms.

&&

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

UPDATE...Parkin
SHORT TERM...TDK
LONG TERM...Vipond
AVIATION...Parkin

Hazardous Weather Outlook
National Weather Service Aberdeen SD
455 AM CDT Fri Aug 27 2021

MNZ039-046-SDZ003>011-015>023-033>037-045-048-051-281000-
Traverse-Big Stone-Corson-Campbell-McPherson-Brown-Marshall-Roberts-
Walworth-Edmunds-Day-Dewey-Potter-Faulk-Spink-Clark-Codington-Grant-
Hamlin-Deuel-Stanley-Sully-Hughes-Hyde-Hand-Jones-Lyman-Buffalo-
455 AM CDT Fri Aug 27 2021 /355 AM MDT Fri Aug 27 2021/

This Hazardous Weather Outlook is for west central Minnesota,
central South Dakota, north central South Dakota and northeast
South Dakota.

.DAY ONE...Today and tonight.

Showers and thunderstorms will move through the region this morning.
There is still potential for a few strong to severe storms, with
strong winds around 60 mph and hail to quarter size. Later this
evening, the next disturbance will move in, with potential for strong
to severe storms over north central South Dakota. Large hail and
strong winds will be possible.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday.

Strong to severe storms are possible on Saturday over northeast South
Dakota and west central Minnesota.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be requested. Weather spotters are encouraged
to submit reports to the National Weather Service in Aberdeen. The
public can submit reports on our web page, Facebook page, or our
Twitter feed.

TMT