115
FXUS63 KABR 161521
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
1021 AM CDT Thu Jul 16 2026

.KEY MESSAGES...

- Hot temperatures and dry conditions are expected through the end
  of the week into the upcoming weekend with readings around 10
  degrees above normal.

- A Heat Advisory remains in effect for central and portions of
  northeast SD today as afternoon heat index values top out around
  100 degrees.

- A pattern change next week could potentially return temperatures
  closer to normal along with increasing chances for precipitation.

&&

.UPDATE...
Issued at 926 AM CDT Thu Jul 16 2026

Smoke has backed into western Big Stone and northern half of
Traverse counties, but as south winds become better organized,
better quality air in eastern South Dakota and southwest
Minnesota will shift northwards.

Otherwise, while dewpoints are a touch high in comparison to the
forecast for later today, they similarly mixed out into the mid
50s to mid 60s yesterday (west to east respectively).

No changes to the forecast of note.

&&

.DISCUSSION...
Issued at 316 AM CDT Thu Jul 16 2026

The main forecast challenge continues to revolve around the ongoing
above normal temperature pattern most of us have been experiencing
this week. More subtle changes are expected to take place during the
next few days, but any noticeable differences from the current hot
and dry stretch of days should be negligible. The upper ridge will
remain centered just off to our south and southeast today,
maintaining a significant influence on our weather. Another day of
hot and dry conditions are expected as 850mb temps remain in the low
20s C east to the mid to upper 20s C west. Afternoon highs will
reach the mid 90s to around 100 degrees across central SD while our
eastern zones remain relatively cooler in the upper 80s to low 90s.
Brought today`s Max Ts more in line with the NBM5.2, which has
handled daytime highs fairly well the last few days. Afternoon heat
index values look to top out in the mid to upper 90s across the
James Valley to the upper 90s to low 100s across central SD. WBGT
values will be highest across central SD with readings in the mid
80s and the HeatRisk will reach the major category from the James
Valley and points west. Based on some of these figures, decided to
drop the Heat Advisory across northeast SD and west central MN but
maintain it from Brown/Spink west through this evening. Guidance
progs the thermal ridge to set up west of the James Valley today.
Given some uncertainty on how far east this thermal ridge makes it
this afternoon, took the conservative approach with the headline
decision. Heat index values east of the James Valley don`t even come
close to Heat Advisory criteria. In fact, forecasted values this
afternoon are more than 5 degrees cooler than the 100 degrees or
higher criteria.

A weakness in the upper ridge will track across mainly ND later
today and Friday. This will help bring an area of low pressure and
associated frontal boundary into the western Dakotas this afternoon
and into our northern and western zones on Friday. The persistent
southerly low level flow will become northerly on Friday. Any
moisture associated with this feature should remain in ND where the
sfc low, warm front and better forcing track. High temperature
projections on Friday will be dependent on the timing of the fropa.
RAP/NAM suggests an earlier passage with some CAA getting underway
during the afternoon hours across our northern zones while other
guidance holds the thermal ridge in across most of the forecast area
through peak heating in the afternoon. The air mass behind this
front is not noticeably cooler by any stretch so am not expecting
any noteworthy relief from the heat. Widespread daytime highs in the
90s to around 100 degrees are still expected with max heat indices
in the mid 90s to low 100s in most areas. For now, will leave the
current Heat Advisory headline in place but future shifts will have
to consider extending it and resurrecting one across our eastern
zones. Sfc high pressure builds southeast across eastern ND into MN
Friday night through Saturday, glancing our eastern zones. Saturday
might actually provide a brief break from the significant heat with
forecasted highs projected to be in the mid to upper 80s east to the
low to mid 90s west. As high pressure slips southeast of the area on
Sunday, southerly flow returns as s/w ridging punches back northeast
across the CWA. So, anticipate widespread 90s for highs in most
zones with low 100s expected again across parts of central SD.

Longer range guidance continues to show a more noteworthy pattern
shift across the Northern Plains as northwesterly flow aloft
returns. A stronger upper trough is progged to shift southeast
across the region early next week suppressing the upper ridge back
across the Rockies and Southern Plains. Pcpn chances return by the
end of the weekend into Monday and possibly beyond through the
middle of next week as potential increases for some upper waves to
traverse the region along associated sfc lows and frontal
boundaries. Temperatures should begin to resemble more normal
readings for late July by that time with highs in the low to mid 80s
and overnight lows in the low 60s.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 606 AM CDT Thu Jul 16 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are forecast through the TAF period, with south
to southeast breezes persisting.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Heat Advisory until 10 PM CDT /9 PM MDT/ this evening for
     SDZ003>006-009-010-015>018-033>037-045-048-051.
MN...None.

&&

$$

UPDATE...07
DISCUSSION...Vipond
AVIATION...MMM