Aberdeen, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

104
FXUS63 KABR 301125
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
625 AM CDT Fri May 30 2025

.KEY MESSAGES...

- Wildfire smoke from Canada will continue to plunge southward into
the region today and tonight and is expected to remain aloft.
Saturday both smoke aloft and near the surface is expected, which
could reduce visibilities.

- 15 to 20% chance of showers and thunderstorms this evening through
early Saturday morning, mainly for portions of central South Dakota.
No severe weather is expected.

- Temperatures will continue to warmup with highs in the upper
70s/80s today, and peaking Monday in the 80s to near 90 (5 to 15
above). Then, much cooler high temperatures are in store for Tuesday
through Thursday of next week.

- Precipitation chances peak at 60 to 80% Monday night and Tuesday.
Probability of rainfall amounts at or over a quarter of an inch is
55 to 80%, highest east of the Missouri River.

&&

.DISCUSSION...
Issued at 306 AM CDT Fri May 30 2025

As of 2AM, no clouds are present, however, a milky sky continues
due to the smoke aloft. Winds remain fairly light between 5-10 mph
with temperatures in the upper 40s to the mid 50s. The main
takeaway for the next several days will be the ongoing wildfire
smoke affecting the region through at least Saturday, above
average temps Sunday and Monday, and the return of showers and
thunderstorms/severe potential early next week.

Northerly flow aloft will turn more north/northwesterly this evening
as the Northern Plains is on the downstream side of a ridge over the
western CONUS. A weak shortwave originating from the Pacific
Northwest will continue its track through and down the ridge and
over the leeside of Rockies/Northern Plains tonight into Saturday
morning. It will continue its track south/southeast and over the
Central Plains through Saturday evening. At the surface, ridging is
over the area, being on the northern fringe of a high pressure
system positioned over the Southern Plains, keeping the area dry.
HRRR VI Smoke Model continues to indicate widespread smoke aloft
(thick at times) over the region today, with the thicker smoke
mainly east of the Missouri River tonight. With this shortwave,
either a very weak cold front, or more likely a surface trough, will
pass over the area late this afternoon through tonight and should be
southeast of the CWA by Saturday morning. Several of the CAMs do
indicate the possibility of spotty light showers/storms with this
weak disturbance, however, timing and placement differ a bit between
the models. So I blended in HRRR/RAP/ECAM to NBM (and capped at 20%
pop due to low confidence) to show for the possible outcomes if they
occur between 00-12Z Saturday. Behind the trough, surface winds will
be shifting from the northwest then northerly towards Saturday
evening as winds aloft will remain northerly. This allows for
ongoing smoke aloft and for smoke to reach the surface as HRRR Near
Surface Smoke Density does indicate this southward plunge starting
Saturday morning and continuing through the day and into the evening
over the CWA. Some of this smoke could be thick at times which could
decrease visibilities.

Clusters agree on this ridge shifting eastward, becoming positively
tilted, Sunday as a trough will setup over the Pacific Coast. As it
progresses eastward Monday/Tuesday, we see more of a messy split
flow with the northern wave advancing eastward a bit quicker than
the southern wave with several shortwaves/vortices within this
pattern. Beyond Monday, Clusters diverge a bit on the actual setup
as hints that the waves merge back together. At the surface, this
will bring in our next low/cold front from the northwest and
tracking southeast through the region Monday through Tuesday, with
the highest pops of 65-80% Monday night into Tuesday morning over
the CWA and 60-80% east of the Missouri River Tuesday. Probability
of NBM 24hr QPF> 0.25", ending 00Z Wednesday is 55-80%, highest east
of the Mo River. Probability of 0.50" is 60-70% east of the Mo
River. We also are watching the possibility of severe weather with
this frontal passing Monday afternoon and evening. In the warm
sector ahead of the cold front, highs will be well in the 80s to 90
and dewpoints in the upper 50s to the lower 60s. SBCAPE values look
to increase to anywhere from 1000 up to 1500-1600 j/kg over south
central SD with MUCAPE possibly over 2000 j/kg in this same area!
Shear, for now, will not be anything impressive around 20-30kts. So
probability of MUCAPE>500 and shear>30 is 40-60% from northeastern
SD through south central SD which is where the SPC has highlighted a
15% chance for severe weather. This is several days out so timing
and track of low may change along with location of mesoscale
parameters. With this system, wind gusts will increase between 20-
30kts both Monday and Tuesday afternoon and evenings. High pressure
will be dominant over the area for the middle of next week.

Temperatures will gradually warm today and through the weekend, with
highs on Sunday and Monday well into the 80s to maybe even around 90
(10-15 degrees above average). There is lower confidence today and
Saturday on how warm we will get with the smoke, which may decrease
the overall highs a few degrees if thick enough. Behind the cold
front, temps will cool back into the 60s and 70s for Tuesday and
Wednesday (5-10 degrees below average).

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 623 AM CDT Fri May 30 2025

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will continue over the next 24 hours. Smoke from
Canadian wildfires may occasionally lower visibility across the
region, mainly Saturday into Sunday but confidence remains where
at to what extent.


&&

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

$$

DISCUSSION...MMM
AVIATION...06