482
FXUS63 KABR 121206
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
706 AM CDT Sun Apr 12 2026

.KEY MESSAGES...

- Isolated weak thunderstorms this morning.

- Warm, dry, and windy later today with record/near record highs
  and critical fire weather conditions for portions of
  central/south  central SD.

- Strong storms possible Monday afternoon. Slight Risk (level 2
  of 5) for severe weather along and east of the Interstate 29
  corridor.

&&

.UPDATE...
Issued at 705 AM CDT Sun Apr 12 2026

Update to get rid of dense fog headlines.

&&

.DISCUSSION...
Issued at 1245 AM CDT Sun Apr 12 2026

Isolated thunderstorms northwest of Aberdeen this morning associated
with a southwest flow shortwave to our northwest. Profiles indicate
a deep dry subcloud layer, with 850mb temperatures reaching their
peak during the morning. NAM BUFKIT profiles indicate as much as
20C dewpoint depressions where 850mb temperatures are close to
+20C. Thus, will include a 20-30% chance for thunder and watch
for isolated strong wind gusts.

Wrap around dry air this morning, helping to scour out remnant low
level moisture, however some higher mid level dewpoint air pivots
back around out of North Dakota. This sets up a gradient across the
CWA from north to south of higher to lower dewpoints respectively.
The main question is how low will these get, especially in areas
highlighted for Red Flag conditions. Otherwise we`re pretty
confident in winds achieving criteria as NAM BUFKIT profiles
continue to indicate deep mixing (up to 8-9kft) and mixed down winds
of 20-30kts. They actually start out the day stronger, but the
gradient weakens after 18Z as the low moves into northwest
Minnesota, especially out in central SD. As for temperatures,
deterministic NBM is still down around the 10th percentile,
with the 25th-75th range down to around 3-4F suggesting a high
confidence forecast which really has us questioning why
deterministic values are so low in comparison. Current
temperatures around 60F means it won`t take much to warm to
NBM deterministic. Will continue to use the NBM mean given
favorable mixing winds/ample sunshine and a lack of additional
mitigating factors.

Zonal flow aloft with a southwest flow shortwave ridge keeps us
clear of precipitation through Monday morning. A weak mid-level
trough comes into the northwestern part of the state late Monday.
There is a warm sector with 850mb temperatures up to +18C over
southeast South Dakota Monday morning, and that warm front weakens
then reforms as the wave comes in later in the day. Cant rule out
elevated convection with the first surge, but the second responds
more as the trough approaches from the west and that is what CAMS
are picking up on. Profiles suggest strong unidirectional flow above
an inversions with stable near surface flow out of the east northeast
for Watertown, though with more curved hodographs down towards
Brookings. NAM has the best CAPE well southeast of the CWA,
HREF puts the favorable area around highway 14 in eastern South
Dakota.

That shortwave heads out Tuesday morning. The next mid level wave of
note comes out of the Colorado Rockies region and pushes east
northeast into southeast South Dakota and Nebraska. Likewise, the
surface low also travels mainly to our south. Up this way, a weak
surface high ridge extends southwards out of Canada into the
Dakotas. This results in a brief mid-week cool down. Another surge
of mild air follows, with the core of the mildest air moving through
Thursday. A much cooler airmass follows for Friday/Saturday.
Temperatures late in the forecast drop to about 10 to 20F below
normal.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 608 AM CDT Sun Apr 12 2026

Terminals KABR,KATY,KPIR,KMBG

Fog and low level wind shear has mostly ended, with lingering 5
miles at MBG in fog for the first hour or so at MBG. Winds will
continue to increase this morning, with gusts of 25-30kts until
gusts end around 00Z Monday. Mainly MVFR ceilings and
visibility may return at MBG/ABR and potentially ATY after 09Z
Monday.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Red Flag Warning from noon CDT /11 AM MDT/ today to 7 PM CDT
     /6 PM MDT/ this evening for SDZ033-035-045-048-051.
MN...None.

&&

$$

UPDATE...06
DISCUSSION...07
AVIATION...06