557
FXUS63 KABR 060602
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
102 AM CDT Wed May 6 2026

.KEY MESSAGES...

- An overall dry forecast for the rest of the week into the weekend.

- 10 to 20 degrees below normal for temperatures today and near
normal Thursday through Saturday.

&&

.DISCUSSION...
Issued at 1258 AM CDT Wed May 6 2026

As of 1am, temps are ranging in the mid 20s to the mid 30s with the
coldest temps over north central SD and winds under 10 mph.
Satellite indicates broken stratus over northeastern SD into west
central MN with more widespread stratus upstream further into ND/MN
tracking southeast. The main highlight will be the ongoing colder
temps once again today and tonight with temps warming back up to
near average for the end of the week. Otherwise, moisture looks to
be minimal.

Northwest flow continues aloft over the Northern Plains within a
troughing pattern on the backside of a cutoff low over eastern
Canada and a highly amplified ridge over the Western Conus/Pacific
Ocean. The region sits on the northeastern/eastern side of high
pressure over MT/WY this morning (12Z) with this high shifting
eastward and centered over the region by this afternoon. It will
continue to shift off towards the east/southeast later on this
evening through tonight. Any diurnal convective showers per
HREF/CAMs look to stay northeast of the CWA but still may see some
afternoon fair wx cumulus over the CWA. RAP indicates another shot
of dry air to move in from the west and northwest this
afternoon/evening over central SD and spreading eastward across the
CWA Thursday before exiting Thursday evening. Due to this, locations
along and west of the Mo River`s RH is forecast to drop between 20-
30% with the lowest along the ABR/UNR CWA. Luckily winds will be
under RFW criteria.

A shortwave out of the Gulf of Alaska will ride down along the
eastern side of the ridge, and its surface low, where the low will
center itself over ~Canada/MT border by 12Z Thursday. It will
continue to track southeast and broaden over WY/SD/NE border
Thursday afternoon and continue to track into the Central Plains
Thursday evening. This is a fairly weak and disorganized system with
the bulk of the light precip expected over western SD/NE into WY,
closer to the center of the low. NBM has backed off on precip
chances that were over our western CWA and pushed them more westward
as Cams show this well with portions of south central SD being
clipped by the rain at most as the low tracks southeastward with
NAMnest the most aggressive in rain chances and a further track
eastward. With still a slight difference in track, went with the NBM
for now. Closer to time and future run of the CAMs will determine if
we need to add pops back in. NBM probability of QPF>0.01 is 30-45%
over our extreme western CWA with prob of 0.10 at 15% or less.

Another weak shortwave coming off the Pacific and riding up and over
the ridge into the Northern Plains, and its very weak surface low,
will position itself over southwestern SD/northwestern NE by 12Z
Saturday. Track and intensity still varies a bit between GEFS/ENS.
Once again, the bulk of the precip will stay to our west and south
(unless we see a further track eastward) with NBM pops of 20% or
less west of the Mo River for now. NBM prob of precip 0.10" is 20-
45% west of the Mo River. This clipper train continues with another
potential system tracking southeast out of Canada and over the
Northern Plains that could bring the potential for light moisture
Monday/Tuesday over far NESD/MN. As as of now, NBM pops are minimal
at 20% or less here with low confidence on exact setup this far out.

Otherwise, Clusters continues with this +PNA pattern, with the CWA
in northwest flow through the weekend into the middle of next week.
Ensembles indicate the ridge staying highly amplified through Sunday
and starting to flatten and broaden a bit early next week. There is
a difference between the Clusters on this as Canadian ensembles keep
it more amplified and ENS more flattened and a shift east with the
low. If we do see more of a flattening of the ridge, winds aloft
would then turn westerly. Confidence is low on the exact setup this
far out.

850mb temps this afternoon will range a couple degrees above and
below 0C (running in the 20 to 35th percentile) as winds at this
level continue out of the northwest and at the surface. Highs for
today may be a few degrees warmer then yesterday but still running
10-20 degrees below normal, ranging in the upper 40s to the mid
50s. 850mb winds will turn more zonal overnight and southerly at the
surface with lows a few degrees warmer at any location ranging int
in the upper 20s to the lower 30s. More milder air filters in from
western Canada for the end of the week. Depending on what the
ridge does, warmer air is forecast to move in early next week,
back in the 70s and 80s by Tuesday. NBM 25-75th spread is 6-10+
degrees this weekend into next week depending on the pattern
aloft which will determine surface features.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1235 AM CDT Wed May 6 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will continue to prevail through the next 24
hours. BKN/OVC VFR CIGs will continue to remain an on/off trend
at KABR/KATY through this forecast cycle. Any periods of
clearing at these northeast SD terminals will likely occur
during the pre-dawn hours through mid morning before clouds
thicken and increase through the remainder of today. KPIR/KMBG
terminals will have a better chance to see longer periods of
clearing to SCT/BKN VFR CIGs.

&&

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

&&

$$

DISCUSSION...MMM
AVIATION...Vipond