295
FXUS63 KABR 191324
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
824 AM CDT Sun Jul 19 2026

.KEY MESSAGES...

- Heat advisory for the James Valley and points west this
  afternoon. Temperatures in the 90s to around 100 degrees and
  dewpoints in the 60s resulting in heat index values around 100
  to 105.

- Storms expected along a cold front late this evening into early
  Monday. A Slight Risk (2 of 5) covers most of the forecast area
  with a Marginal Risk (1 of 5) around and south of I-90. Main
  threat is high winds with hail up to 1 inch as a secondary
  threat. Not expecting a lot of moisture overall either.

- Heightened Fire Weather threat for Monday. Lightning starts
  from storms Monday morning are possible. Northwest winds of 25
  to 40 mph during the day, with drier air. Afternoon humidity
  down to around 20% across the Missouri Valley region, 30-40%
  across northeast South Dakota.

&&

.UPDATE...
Issued at 820 AM CDT Sun Jul 19 2026

Warm advection elevated convection continues to make a slow
progression across the James valley with some lighter showers
even back into the Missouri valley. We did get a radar
indicated (with decent ground truth) swath of 1/2 to 1 inch
from western Dewey down through Sully/Hughes county and down
towards Chamberlain area, roughly 15 miles width, with another
more broadly 1/2" up across Edmunds/McPherson counties. Overall
trends in convective intensity have generally been downwards
here recently as should be expected with warm advection
nocturnally enhanced convection and likewise suggested by CAMS.
There is a lot of convective debris which will have an impact
on daytime heating. For now, will leave headlines in place as
cloud cover limited sunshine will be replaced by a equivalent
bump up in humidity. Deterministic values for highs today do
show a slight tick downwards between the Missouri and James
valley though. Will have to wait another hour or two to compare
NBM/HREF to the current forecast to assess if highs should be
lowered.

Still looking at storms tonight. Timing has shifted and CAMS are
a lot less consistent. Will have more details in the afternoon
AFD.

Again fire weather for Monday remains a concern. Likewise will
address in the afternoon AFD.



&&

.DISCUSSION...
Issued at 123 AM CDT Sun Jul 19 2026

As of 1 AM CDT, temperatures around the area are in the upper 60s to
low 70s with winds out of the southeast. Heat will return today with
highs in the 90s to near 100 and heat index values in the upper 90s
to low 100s. A Heat Advisory is in effect for areas along and west
of the James Valley from 1 PM to 9 PM CDT. There is also a Slight
Risk (level 2 out of 5) for severe storms this evening across
most of the forecast area with a Marginal Risk (level 1 out of 5)
around and south of I-90. The main threat will be mainly strong
wind gusts of 60-75 mph, with hail up to an inch in diameter as a
secondary threat. There are some showers/thunderstorms expected
this morning, but no severe weather is expected from these storms.

Looking ahead, heat continues Monday with similar highs and heat
index values. Winds will also increase Monday with a low pressure
system and cold front moving across the area. Winds are forecast to
gust 30-35 mph mainly north of Hwy 14. This will increase fire
danger concerns due to continued warm temperatures and dry fuels.
Tuesday through the end of the work week, temperatures return to
normal for this time of year. Models are starting to show a signal
for a return of above average temperatures for the weekend. There
are a couple chances for storms during the second half of the week,
although chances are generally less than 50%. A plume of rather
concentrated smoke moves in aloft Monday afternoon which will create
milky skies. HRRR smoke shows a bit of surface level smoke moving in
as well. This could result in a slight reduction in visibilities.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 634 AM CDT Sun Jul 19 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are expected to prevail today. Two rounds of
showers and thunderstorms wll affect the region today. The first
is moving through this morning. The next will move into central
SD thsi evening before progressing eastward overnight. Storms
this evening may be severe with strong winds the primary threat.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Heat Advisory from 1 PM CDT /noon MDT/ this afternoon to 9 PM
     CDT /8 PM MDT/ this evening for SDZ003>006-009-010-
     015>018-033>037-045-048-051.
MN...None.

&&

$$

UPDATE...07
DISCUSSION...13
AVIATION...20