320
FXUS63 KABR 141758 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1258 PM CDT Sat Jun 14 2025

.KEY MESSAGES...

- There is a Marginal risk (1 out of 5) for severe thunderstorms
  over most of the forecast area today/tonight. Main threat is
  marginally severe hail around quarter size.

- Strong to severe storms possible Sunday and Monday as Slight risk
  area (threat level 2 of 5) pushes eastward through the region.

&&

.UPDATE...
Issued at 1252 PM CDT Sat Jun 14 2025

Aviation discussion updated below for the 18Z TAFs.

UPDATE Issued at 1025 AM CDT Sat Jun 14 2025

Watching the MCV/vort max moving eastward along the ND/SD border
this morning, and it continues to generate isolated showers, with
an occasional thundershower. Adjusted PoPs through the morning to
better reflect overall trends, which looks to be limited coverage
through a good part of the day before rain chances increase for
the overnight hours. Also seeing lingering areas of fog across the
region, more so over the Coteau, with another area along the I-90
corridor across Jones/Lyman counties. Did issue an SPS earlier for
Jones/Lyman to account for what appears to be (based on web cams
and a report) a bit more dense fog down that way. Otherwise,
clouds and resultant high temperatures will be the big challenge
today. Going to have to clear out somewhat to realize our forecast
high temperatures. Models still do suggest partial clearing
throughout the afternoon, but will have to monitor trends and
there remains some "bust potential" for high temps today.

&&

.DISCUSSION...
Issued at 245 AM CDT Sat Jun 14 2025

As of 2 AM CDT, some thunderstorms are starting to move into our
western CWA. At this point, these storms are not severe.
Temperatures around the region are in the 50s with winds out of the
east between 10 and 15 mph.

We open the forecast period this morning with an upper level ridge
over the area. This will generally remain in place through the
day Thursday before transitioning to more zonal flow Friday with
another ridge building in Saturday. The biggest story of the 7 day
is several days of severe weather potential linked to our parade
of shortwaves.

Today, we have a marginal risk (level 1 out of 5) for severe
thunderstorms across almost our entire CWA. Jones county is in a
Slight risk (level 2 out of 5) CAMs show some showers developing to
our west during the morning hours, however, the storms with severe
potential don`t develop until the late afternoon, potentially
lasting into the overnight hours (this would be mainly eastern SD)
as a LLJ sets up. CAMs are showing the majority of the activity in
our southern CWA, mainly along and south of Hwy 14, with some
activity possible east of the James River. The best MLCAPE is mainly
south of our CWA, although some models show areas of around 1500
J/kg in our southern CWA. Lapse rates in this area are 7 C/km or
greater. Main threats with these storms will be large hail and
damaging wind gusts, if they become severe, which is not guaranteed.

Sunday, we are again outlooked for severe thunderstorms: a Slight
risk (level 2 out of 5) over central SD and a Marginal risk (level 1
out of 5) for the rest of northeastern SD. Again, this looks to be a
late afternoon to potentially overnight event. The NAM Nest and FV3
are the main CAMs at this time and both show potential for storms
entering the western CWA after midnight and moving east into early
Monday morning. Looking at deterministic models for severe
parameters, the NAM is definitely the most excited about this,
bringing MLCAPE values of almost 4000 J/kg to eastern SD by Sunday
evening, this is a serious outlier, the other 3 main deterministic
models show closer to 2000-2500 J/kg at this time. As for other
parameters, bulk shear looks better over southern SD for the most
part, not too much above 30 kts really. Lapse rates are above 7
C/km, with some closer to 8 in our southern CWA and southern SD.
Again, with this the main threats would be large hail and damaging
wind gusts.

Monday, has a 15% area for severe thunderstorms already at Day 4.
Details are more limited since it is still a few days out, but
basically, instability and moisture hang around and as a surface
front moves through, this will provide some lift to potentially pop
off some storms. Chances for showers and storms continue through at
least Wednesday. Temperatures through the period are still expected
to be in the 70s and 80s, or about normal for this time of year.
Some elevated smoke is anticipated for today, but nothing near the
surface.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1252 PM CDT Sat Jun 14 2025

Terminals KABR,KATY,KPIR,KMBG

Still quite a bit of coverage of MVFR CIGs to start off the TAF
period, and these lower clouds will continue to some degree
through the TAF period, although breaks are expected at times this
afternoon. Overnight, CIGs are forecast to lower into IFR again,
with a return of FG/BR for at least the KABR/KATY regions, but did
include mention for KPIR/KMBG as well. Scattered -TSRA/TSRA also
expected during the overnight hours, but low confidence on exactly
when and where, although models suggest northeastern SD likely the
best area for this. Included a PROB30 mention for this across
KABR/KATY.

&&

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

$$

UPDATE...TMT
DISCUSSION...13
AVIATION...TMT