284
FXUS63 KABR 261734 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1234 PM CDT Thu Jun 26 2025

.KEY MESSAGES...

- Showers and thunderstorms persist across the area today.
  Precipitation will end from east to west through the day with
  lingering showers and clouds holding tough the longest through
  the late afternoon across northeast SD and west central MN.

- Severe storm chances return Friday/Friday night, with a slight
  risk (level 2 of 5) for severe weather across most of central
  and northeast South Dakota. Additional chances for severe
  weather continue on Saturday with a slight risk (level 2 of 5)
  for severe weather across northeast South Dakota and west
  central Minnesota.

- Temperatures will remain rather warm along with higher levels of
  humidity on Friday through the weekend. Drier conditions will be
  possible early next week as warm temperatures continue.

&&

.UPDATE...
Issued at 1226 PM CDT Thu Jun 26 2025

Updated forecast for the 18Z TAFs below.

UPDATE Issued at 1000 AM CDT Thu Jun 26 2025

With ongoing low to near zero visibility over portions of the
Sisseton Hills, per several webcams in this area, the Fog
Advisory has been extended until noon. Otherwise, radar continues
to indicate a broad area of ongoing light to moderate rain
showers, east of the Missouri River, slowly pushing
northeastward. Models indicate this rain should exit the eastern
portions of the CWA by this evening. With this slow moving rain
and still reports of minor flooding issues, the Flood Warning has
been extending until 7PM just to be on the safe side. Additional
rainfall amounts up to an inch are possible through this evening.
Otherwise the forecast remains on track.

UPDATE Issued at 606 AM CDT Thu Jun 26 2025

The aviation discussion has been updated for the 12Z TAFS.

&&

.DISCUSSION...
Issued at 510 AM CDT Thu Jun 26 2025

An unsettled weather pattern continues to affect this forecast area
early this morning as scattered showers and thunderstorms dot parts
of central and northeast SD. Most of this activity has been tame or
sub-severe, but it has been putting out some locally heavy rain at
times. Based on latest guidance/CAMs, this activity will continue to
evolve eastward from central SD into the James Valley this morning
before shifting into the remainder of northeast SD and west central
Minnesota closer to midday into the afternoon hours. Foggy
conditions have also developed in parts of the forecast area. This
is especially true in our eastern zones including the the I-29
corridor west into the Glacial Lakes region. Area webcams in these
areas indicate some widespread fog occurring and is dense in some
locations from Deuel and Grant Counties north into Roberts, Marshall
and Day Counties. Visibilities are not expected to improve anytime
soon, at least until around 14Z-15Z and as a result have issued
issue a dense fog advisory for these areas.

The upper flow pattern today will feature an upper trough axis
shifting west to east across SD. This will aid in kicking out a
quasi-stationary sfc boundary and its associated sfc low pressure
system that has stubbornly remained in place across southern
sections of SD for the last couple of days. As the precipitation in
central SD moves east, it will be running into sfc ridging nosing
into our northeast zones from a sfc high pressure system in Ontario.
So, coverage may become limited or scattered with time. With the
expected timing of the passage of the upper trough axis late this
afternoon across our eastern zones, precip chances will linger in
those areas into the afternoon hours before either waning or pushing
east out of our area. Would anticipate just generic showers and/or
storms as the atmosphere remains stable. Clouds will really be tough
to break from the James Valley and points east through most of the
day. Any potential for clearing will be confined to central SD
closer to midday and afternoon.

Low amplitude shortwave ridging is progged to shift into the Dakotas
by the end of today into Friday. This will give our area a respite
from the precip, but it will be brief. The aforementioned sfc ridge
shifts east into MN on Friday while lee side sfc troughing develops
across the Northern High Plains in response to mid level shortwave
energy tracking into the region from the Great Basin. Strengthening
low level flow across our forecast area on Friday will advect in
richer gulf moisture with dew point temperatures returning to the
mid to upper 60s F by the afternoon hours. Modest to strong daytime
heating will take place with 850mb temperatures returning to the
upper teens C to the low 20s C in the afternoon. This will yield
daytime highs mid 80s to low 90s from the James Valley and points
west across central SD. All these ingredients combine to lead to
moderate to strong instability in the afternoon. Strengthening mid
level flow will result in very efficient deep layer shear. As the
sfc trough shifts into the western Dakotas during the afternoon,
anticipate convection to break out. Supercells will be possible
capable of producing large hail and damaging winds and possibly a
tornado or two. SPC currently highlights a slight risk (level 2 of
5) for severe weather across most of central into northeast SD
Friday afternoon into Friday night. This activity is progged to work
east and southeast downstream through central and northeast areas of
SD by the late afternoon through the evening. As of now, consensus
indicates there could be two areas of convection. One would be
across ND and if this verifies, those complex of storms could shift
southeast into our forecast area affecting our northeast zones. The
other could potentially be around the Black Hills region where
storms could initiate and shift off east to southeast into the
Plains perhaps affecting our southern zones. Just will have to
monitor trends the next 24 to 36 hours to see how this event plays
out.

For the weekend into early next week, an unsettled pattern will
persist. More storms are expected on Saturday with the focus for
severe weather shifting a bit farther east than Friday`s outlook.
SPC currently highlights a slight risk (level 2 of 5) for severe
weather across northeast SD and west central MN on Saturday. A
similar setup to Friday`s activity is anticipated with convection
firing in the vicinity of a sfc boundary and shifting east and
southeast with time Saturday afternoon into Saturday night. All
modes of severe weather threats will again be possible during this
time. Beyond the weekend, early next week it could begin to dry out
again and turn more quiet although temperature trends appear they
will remain rather warm and summer-like the first half of next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1226 PM CDT Thu Jun 26 2025

Terminals KABR,KATY,KPIR,KMBG

Light to moderate rain showers continue over the James River
Valley and eastward, with the rain continuing its path northeast
into ND/MN.The last of the rain should exit the eastern portions
of SD by this evening with dry conditions tonight into Friday
morning. With ongoing low level moisture and post rain, fog is
possible (could be dense in some areas of the James River
Valley/Coteau) Friday morning. Cigs remain at IFR/MVFR at
KPIR/KMBG with KABR improving to MVFR/VFR later on this afternoon.
KABR may fall back to lower cigs if the fog forms early Friday
with KATY remaining in IFR to possibly LIFR tonight into early
Friday morning.

&&

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

$$

UPDATE...MMM
DISCUSSION...Vipond
AVIATION...MMM