058
FXUS63 KABR 251346 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
846 AM CDT Fri Jul 25 2025

.KEY MESSAGES...

- There is a 30 percent chance of showers and thunderstorms late
  this afternoon through tonight, mainly over central South
  Dakota. Then again Saturday night over north central SD. There
  is a Marginal Risk for severe storms (level 1 out of 5) in both
  of these areas. If storms develop, a few will be capable of
  producing hail to 1 inch in diameter and winds to around 60 mph.


- Hot and humid conditions are in store Saturday through Monday.
  Heat index values will be in the 100 to 105 degree range over
  portions of south central to east central SD.

- Cooler air (highs in the 70s to around 80) and drier, less
  humid, conditions will arrive Wednesday and continue through at
  least Friday.

&&

.UPDATE...
Issued at 844 AM CDT Fri Jul 25 2025

No changes planned to the today period forecast.

&&

.DISCUSSION...
Issued at 356 AM CDT Fri Jul 25 2025

We remain stuck in a pattern with low pressure to our west, pumping
in hot and humid conditions. Winds today will be increasing out of
the south with gusts 25 to 30kts west of the James River. Dewpoints
near 70F and temperatures in the 80s to low 90s (highest west of the
MO River) will result in heat index values staying just below 100F.

A change is in store for Saturday, with temperatures about 5F
higher. Dewpoints will be similar, but in the low 70s over eastern
SD. Heat index values will be closer to 100 to 105 Saturday
afternoon over portions of south central SD, and close to these
values over the James River Valley. A Heat Advisory has been issued
for 1-8pm CT Saturday afternoon for our 3 southwestern counties
(Jones/Lyman/Buffalo). Confidence is high on temperatures for the
entire forecast period, with the 25-75th percentiles from the NBM
being within a 5 degree range. Confidence is lowest on highs Sunday,
when heat index values are currently forecast to get to near 100 to
105 degrees over all of our southern counties. However, how long
they are in this range varies significantly. Additional heat
headlines may be needed Sunday.

As for precipitation and severe weather chances, there is a 30
percent chance of showers and thunderstorms late this afternoon
through tonight, mainly over central South Dakota. The low level jet
will strengthen to 30-40kts around 900mb 03-12Z Sunday, assisting in
thunderstorm maintenance. We`ll be watching on how storms developing
over eastern MT/WY and the western Dakotas evolve. We have to
potential for a couple of rounds of storms, the first late this
afternoon over central SD after 22Z into the early evening hours,
with the 2nd overnight with winds being more of a concern over our
northern counties with most of the storms staying in ND.

During the day Saturday, 700mb temperatures will be in the 12-14C
ranges, highest west, helping to limit storms to later in the
afternoon and into Saturday night. Given storms initiating again
over the western Dakotas and eastern WY, the highest chances will be
over central SD.

We`re still looking for the surface low to shift over southern SD
Sunday night. Strong high pressure over Canada will push a ridge
into our area behind the low, with drier and cooler air anticipated.
We expect the surface high to sink over the eastern Dakotas and MN
Wednesday night through Thursday night before slowly exiting east.
Temperatures Tuesday on will be much lower, topping out in the 70s
to low 80s (highest Tuesday over south central SD).

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 656 AM CDT Fri Jul 25 2025

Terminals KABR,KATY,KPIR,KMBG

5-6SM vis is at ABR and ATY this morning but should quickly mix
back to VFR by 13Z. Otherwise, isolated showers remain mainly over
ND this morning. Confidence is low on if/when showers or storms
will return, but the highest potential is for storms to be near
MBG 01-08Z. Still, that large of a TEMPO group seemed too much
when storms would be possible for 1-2 hours. A higher chance,
above 30% remains over ND this evening and overnight.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Heat Advisory from 1 PM to 8 PM CDT Saturday for SDZ045-048-051.

MN...None.
&&

$$

UPDATE...10
DISCUSSION...06
AVIATION...06