880
FXUS63 KABR 260232 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
932 PM CDT Wed Jun 25 2025

.KEY MESSAGES...

- Showers and thunderstorms return to the area this evening
  through Thursday morning, with the highest chances (50-75%) over
  central SD. There is a marginal risk (level 1 out 5) for severe
  storms along and west of the Missouri River with the main
  threat being wind gusts to 60 mph and brief heavy downpours.

- 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.

- Heat and humidity return late this week through the weekend with
  additional chances for precipitation possible.

&&

.UPDATE...
Issued at 925 PM CDT Wed Jun 25 2025

The forecast appears to be in good shape. Thunderstorms are
developing across the far southern forecast area along a stalled
out frontal boundary, while ongoing convection over UNR`s forecast
area ever so slowly makes its way toward the western/southwestern
edge of this CWA. Given the set-up of 500-1000J/kg of MUCAPE and
25-30kts of deep layer shear over a surface boundary for forcing
and a stout upper level jet streak (100+knots) for lift, should
see thunderstorm potential persist throughout the night, and
mainly south of U.S. Highway 212. Cloudy conditions overnight
should help keep temperatures up. But, overall, lows in the mid to
upper 50s should suffice.

UPDATE Issued at 634 PM CDT Wed Jun 25 2025

See below for an aviation forecast discussion for the 00Z TAFs.

&&

.SHORT TERM /THIS EVENING THROUGH THURSDAY NIGHT/...
Issued at 254 PM CDT Wed Jun 25 2025

As of 230pm skies are overall cloudy, with the thickest/lowest
clouds over the eastern CWA closer to the low. Low stratus/fog has
reduced visibilities to around and less than 1/2 mile over the
higher elevations of the Prairie Coteau (very localized). Radar
indicates lingering light rain, pushing northeast, over
Deuel/Grant/Big Stone counties with overall dry conditions across
the rest of the CWA. Quite the heavy rain we have had since early
this morning over portions of northeastern SD. Rainfall reports
have ranged from 3-6 inches over portions of Grant, Day, Roberts,
and Spink counties, with the highest report of 6.3" near Garden
City in Codington County.

Southwest flow continues aloft as the Northern Plains is sandwiched
between a trough to our west and a ridge to our east with a mid
level high over the southeastern U.S. Short term models continue to
show waves of mid level energy in this southwest flow moving in over
the Northern Plains, with the strongest waves of energy over MT/ND
(associated with a deeper shortwave trough), this evening and a
continuous line of energy from NE, through southeastern SD, into MN
through Thursday morning. At the surface, the front will continue to
hover over the SD/NE border through the overnight as another low
travels across this boundary. This shortwave over MT/ND will shift
east/northeast through the night to help move this low and frontal
boundary to the east/northeast, with the low over southeastern
SD/northwestern IA (and its trailing cold front through NE) by 12Z.
We also have quite the ongoing monsoonal moisture as 12Z sounding
showed a saturated column pretty much from the surface through 200mb
with the freezing height at 12.7K feet! NAEFs indicates mean
specific humidity about 2-3 standard deviations above climo from 500-
925mb, highest over southeastern SD into MN through Thursday
morning. Also, this morning`s PWAT value was 1.76" with the record
for this day standing at 1.85", so we are well over the 90th
percentile. NAEFS indicates PWAT values around 1.50" up to 2.00",
with the highest value over far southeastern SD. This runs about run
2-3 standard deviations above climo. With the synoptic setup plus a
deep warm cloud layer and low level moisture advection, all of this
led to heavy rainfall over far northeastern SD into west central MN
(and training).

CAMs indicates additional showers and thunderstorms moving in off
the high terrain from the west and southwest with this front/low and
expected to move into central SD late this afternoon into this
evening, with this precip spreading east/northeastward across the
CWA through the night. However these models are struggling on exact
placement/timing between each other and on how this next round of
precip will track. So kept the pops broadbrushed ranging between 30
to 80%, highest over our southern half of the CWA. These may need to
be adjusted through the night. Latest HREF indicates instability
remaining on the marginal side (up to 1000 j/kg over central SD) and
shear around 30 kts. With this, SPC has backed off on the marginal
threat and now is only highlighting this risk mainly along and west
of the Missouri River, with the main threat being strong winds up to
60 mph. As the storms track east/northeast into the eastern CWA they
should remain below severe limits, due to the lack of instability.
Latest run of the models show the precip should exiting our far
eastern CWA by the midday. An additional few hundredths to a half
inch of rainfall (highest over south central SD) is possible this
evening through Thursday morning. However, any stronger storm
could produce heavier rainfall amounts. Dry conditions expected
Thursday night into Friday morning.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 254 PM CDT Wed Jun 25 2025

We start the long term Friday morning with westerly flow aloft that
will continue through Sunday evening before a trough moves in from
the northwest. This trough will build south and move west to east
across SD Monday, exiting the region Monday evening into early
Tuesday morning. We stay on the downwind side of a ridge through the
end of the period.

SPC has a slight risk (level 2 out of 5) for scattered severe
thunderstorms for central SD and areas west of the James River
Valley. ML lapse rates are between 7.5 and 8.5 C/km with MLCAPE
values between 1500 and 2500 J/kg and bulk shear between 35 and 45
kts. Far eastern SD and western MN are in a marginal risk (level 1
out of 5) for isolated severe storms. In this area, storms are
expected more in the evening, with MLCAPE values between 1000 and
2500 J/kg, bulk shear in the 25 to 40kt range, and slightly lower
lapse rates, between 7 and 8 C/km. A bit of a LLJ sets up Friday
night over eastern SD and may help support elevated overnight
storms. Main threats will be large hail and damaging wind gusts.
Storms may be possible again Saturday later afternoon and evening
with ample instability, though shear is more on the marginal side.
Confidence for storms on Saturday is low at this time.

Highs through the period are expected to be in the upper 80s to low
90s with Saturday as the hottest day. This will be about 5-10
degrees above normal. Winds are not expected to be anything out of
the ordinary through the period, although wind gusts may become
erratic in and around thunderstorms.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 634 PM CDT Wed Jun 25 2025

Terminals KABR,KATY,KPIR,KMBG

Cigs will remain between MVFR/IFR (with even drops to LIFR) due
to the low stratus clouds (and possibly fog) at KABR/KATY/KMBG
through, at least, 15Z Thursday of the TAF period. VFR conditions
at KPIR are forecast to drop to MVFR (low probability of reaching
IFR) overnight, before improving back to VFR Thursday morning.

Currently, there are no showers or thunderstorms near any
terminals. But, guidance suggests there is a low probability of
late night/early morning showers and/or weak thunderstorms passing
by/over the KPIR and KATY terminals. Prob30`s are preliminarily in
place there to account for this potential.

&&

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

$$

UPDATE...10
SHORT TERM...MMM
LONG TERM...13
AVIATION...10