193
FXUS63 KABR 151747 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1247 PM CDT Tue Jul 15 2025

.KEY MESSAGES...

- A slight risk (level 2 out of 5) for severe thunderstorms will
  be possible this afternoon and evening south of a line from
  Wheaton, MN to Vivian, SD. A marginal risk (level 1 out of 5)
  for severe weather is in place elsewhere. The primary threats
  will be damaging winds, large hail, and heavy rain.

- Near-surface smoke moving through North Dakota will spread down
  into South Dakota by early this evening, potentially reducing
  visibility down to 2 to 4 miles.

- Heavy rain is possible along and east of the James River into
  west central Minnesota Tuesday into early Wednesday.

- There will be a noticeable cool-down midweek with highs
  potentially 15 to 20 degrees below normal Wednesday and 10 to 15
  degrees below normal Thursday.

&&

.UPDATE...
Issued at 1238 PM CDT Tue Jul 15 2025

See below for an aviation forecast discussion for the 18Z TAFs.

UPDATE Issued at 858 AM CDT Tue Jul 15 2025

No changes planned right now for the today periods forecast.
(Stationary for the moment) cold frontal boundary is analyzed over
this CWA from near Murdo up to Faulkton to Ortonville. There are
some scattered showers and a couple thunderstorms around the
region this morning, mainly along or north of the boundary. Over
the next 6 hours, instability along/south of the boundary could be
up to 1500J/kg CAPE with accompanying deep layer shear of around
30-35 knots. There are hints that a supercell storm mode could
exist for any storms that can develop over this CWA before the
boundary/forcing moves south and east of this area. Still thinking
there is mainly just a hail/wind threat with convection early this
afternoon. But low level/surface vorticity does increase notably
this afternoon along the boundary, so any convection that can
anchor on the front could incur a localized tornado risk.

&&

.DISCUSSION...
Issued at 427 AM CDT Tue Jul 15 2025

Showers continue to linger in and to the north of the low that
stretches from south central SD northeast toward the Sisseton Hills
early this morning. Hi-res CAMs keep this activity going through
morning and then begin to increase the coverage this afternoon.
General thinking is that CAPE will be high enough south of the cold
front (2000 to 3000 J/kg) to support severe storms. There is a
slight risk (level 2 of 5) south of a line from Wheaton to Vivian
this afternoon and evening mainly for strong, gusty winds and
quarter sized hail. There`s still some discrepancies on the exact
placement and timing of the front. Frontal forcing will be enhanced
by 7.5 to 8.5 degree/km lapse rates and shortwave activity again.
Additionally, the increased threat for localized heavy rain remains
for the James Valley east, especially around the Coteau and Sisseton
Hills. Storms may train or move very slowly in the axis of the low.

Much cooler temperatures are expected today behind the cold front
with temperatures falling in the afternoon into the 60s across the
northern tier. South of the front, highs in the 80s are forecast.
Rain continues through tonight with a brief lull on Wednesday
morning before another wave moves in from the west in the upper
trough. Highs on Wednesday will range 15 to 20 degrees below
average, topping out in the low to mid 60s. The diurnal range
between overnight lows and Wednesday`s highs may need a slight
adjustment given the expected cloud cover.

Surface high pressure builds in Wednesday night with drier
conditions. Southerly flow returns Thursday ahead of a lee side low
in Wyoming. This sets up the potential for further chances of
showers and thunderstorms Thursday night and then Friday into
Saturday as the low moves into SD and NE. The pattern remains active
through Tuesday.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1238 PM CDT Tue Jul 15 2025

Terminals KABR,KATY,KPIR,KMBG

Outside of thunderstorms, prevailing VFR conditions at KABR, KATY
and KPIR will be deteriorating to MVFR/IFR (joining KMBG)
conditions in low stratus over the next 6 to 12 hours behind a
cold front slinking southward toward Nebraska and southeast South
Dakota. Showers and thunderstorms continue across the region this
afternoon and are expected to last into this evening before moving
south and east out of this region. An additional round of showers
is expected to work into central South Dakota Wednesday morning.

&&

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

$$

UPDATE...10
DISCUSSION...20
AVIATION...10