535
FXUS63 KABR 170542 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1242 AM CDT Tue Jun 17 2025

.KEY MESSAGES...

- The front has moved east of the CWA. Severe weather is no longer
  expected for far northeast South Dakota, nor Big Stone or
  Traverse counties.

- The next round of showers and weak storms (30-60% chance) comes
  in from the west late this evening and overnight. An isolated
  stronger storm or two out by the Pierre area could contain hail
  to 1" and wind gusts to 60mph.

- Temperatures are forecast to warm to 10 to 20 degrees above
  normal by the end of the week, where there is a 40 to 60 percent
  chance temperatures could climb to or above 100F degrees.

&&

.UPDATE...
Issued at 1236 AM CDT Tue Jun 17 2025

See below for an aviation forecast discussion for the 06Z TAFs.

UPDATE Issued at 710 PM CDT Mon Jun 16 2025

The afternoon fair weather cumulus over northeastern SD and west
central MN will diminish shortly with the loss of daytime heating.
We`ll be monitoring for shower and thunderstorm development over
our southwestern counties of central SD after around 04Z that may
bring moderate rain to that area. If a couple of strong to severe
storms, it would be most likely between 06-09Z Tuesday. Only minor
adjustments have been made to the ongoing forecast.

&&

.DISCUSSION...

Issued at 315 PM CDT Mon Jun 16 2025

The front is now on the SD/MN state line and moving quickly east
rapidly diminishing the severe weather risk for the area, though
satellite does show some bubbling cumulus along the boundary and SPC
mesoanalysis suggesting its uncapped in Traverse county. Will need
to watch this area for the next hour or two as severe weather
indicies increase the farther east into Minnesota. Once that window
is closed however, should be dry through the afternoon/evening. At
00Z, a shortwave will have lifted out of the intermountain west into
eastern Wyoming and far western South Dakota.  CAMS highlight
convection across western SD/Nebraska this afternoon/evening
associated with the wave. No suggestion of a low level jet to keep
this supported and organized with loss of daytime heating, so the
wave making its wave across the southern half of South Dakota means
only scattered to isolated elevated storms in a primarily
unidirectional southwesterly to westerly mid-level shear profile,
meaning a low risk for hail and straight line winds.

CAMS continue to move showers/storms east into Tuesday, with re-
invigoration due to diabatic heating. The shear profiles is weaker
(0-6km roughly 25-30kts) with winds 10kts or less in the lowest
10kft, meaning a limited severe weather threat if any.  Looks like
there are two weak waves in the NAM with the next coming through
late Tuesday for additional chances for weak storms into Wednesday,
however we start to see ridging out west on the increase helping to
support limited moisture Wednesday night/Thursday.

A southwest flow oriented wave over the intermountain west lifts
into the region Friday, with a plume of mid/high level moisture and
a surge in very warm mild level air. 700mb temperatures are nearing
3 standard deviations above climo, with the EC up to +20C. In the
low levels, low confidence with regards to how hot and humid it will
get, with weak frontal systems evident in the 850/925mb temperature
fields, though handled differently between deterministic models.
Regardless, surface based convection east river will be impossibly
capped, though we cant rule out elevated convection with the subtle
southwest flow waves. This very mild air aloft will persist into
Sunday/Monday as an upper low sits across the intermountain west.

Current NBM deterministic values may be underdoing the degree of this
heat, with forecast values at the bottom end of the 25/75th
percentile box and whisker plots - which also shows a 8-10 degree F
range for highs Thursday-Monday. If we were to lean closer to the
higher range of the percentiles, the forecast would call for highs in
the mid/upper 90s to possibly over 100F for Pierre. As models get
into better alignment expect forecast highs to increase.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1236 AM CDT Tue Jun 17 2025

Terminals KABR,KATY,KPIR,KMBG

While mainly VFR conditions are expected over most of the next 24
hours, fog and showers or a thunderstorm could bring lower ceilings
or visibilities overnight into mid-morning Tuesday, particularly at
ATY, ABR, and PIR. MVFR to IFR ceilings are expected at ATY and ABR
07-15Z Tuesday. Confidence is low at ABR if they will get to IFR
visibility, but the latest trend is for lower clouds to slide in
overnight. For PIR, VCSH and TEMPO thunderstorms have been included
from around 07-12Z Tuesday, with another potential for showers or a
thunderstorm in the afternoon.

&&

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

$$

UPDATE...10
DISCUSSION...07
AVIATION...10