626
FXUS63 KABR 071145 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
645 AM CDT Tue Jul 7 2026

.KEY MESSAGES...

- A Slight Risk for severe thunderstorms (a level 2 out of 5
  threat) is in place today. All severe threats, including wind
  of 60 to 70 miles per hour, hail of 1 inch in diameter, and
  tornadoes will be possible.

- This is also a Slight Risk for excessive rainfall leading to
  flash flooding (a level 2 of 4 threat) in place over much of
  the area today. The greatest chances for excessive rainfall
  will be over north central and northeast SD as well as western
  MN. These areas are expected to see at least 1-2" of rain,
  with the heaviest rain expected in the evening. Areas that see
  multiple round of storms may see as much as 2-4" of rain in
  total.

- A slight cooldown is expected Wednesday through at least
  Thursday, with widespread near-normal to just below normal
  high temperatures (low to mid 80s). Signs point to a warming
  trend beginning by the end of the week, and highs may
  potentially hit triple digits over the weekend.

&&

.UPDATE...
Issued at 638 AM CDT Tue Jul 7 2026

See below for an aviation forecast discussion for the 12Z TAFs.

&&

.DISCUSSION...
Issued at 311 AM CDT Tue Jul 7 2026

As of 07Z this morning, the last of the lingering thunderstorms have
moved out of the Aberdeen forecast area, and the early morning hours
are expected to be fairly quiet until storms move in again over
north central South Dakota after sunrise. Temperatures trend
slightly cooler this afternoon, with highs ranging from the mid 80s
to mid 90s. Pressure gradient tightens a bit this afternoon, meaning
that wind gusts may reach as high as 25-30 knots, particularly along
the Missouri River.

Another round of thunderstorms is expected today, and a Slight Risk
for severe weather covers the area. A stationary front will settle
over the region, providing a source of lift for the storms. The best
severe environment will be on the southern side of the front, where
a CAPE/shear combo of 2000 J/kg and 30-40 knots will be in place,
supporting the potential for hail. Wind will also be a threat, again
south of the front with some marginal DCAPE (up to 1000 J/kg) in the
area. There is also a bit of a signal for tornado potential along
the front. Strong low-level helicity will reach well above 200
m2/s2, and 0-1km shear will increase. With the potential for low
LCLs along the boundary, conditions may line up in such a way as to
support the tornado threat.

With the stationary front settled in across the region, there is
also some concern for flash flooding potential. A southerly to
southwesterly low-level jet will move air parcels over the front,
and creating the potential for storms to also develop on the north
side of the front. Steering winds will be out of the west, generally
parallel to the front. Therefore, the setup will potentially be in
place for training storms to develop. A number of favorable
ingredients are in place, including a long skinny CAPE profile,
PWATs upwards of 1.75" (well above the 90th percentile for this time
of year), moist low to mid-levels, and a warm cloud layer >10k feet.
Cloud layer mean wind and Corfidi upshear vectors looks to both be a
bit high, around 25 to 30 knots. These drawbacks could be less
of a concern if training storms do indeed develop. With all of
that in mind, the flooding threat comes down to two questions:
First, will the low-level flow be strong enough to sustain
continuous storms, and second, where exactly will the front set
up? On the latter point, there has been some increasing signal
for the front to become oriented in a more southwest to
northeast direction, which would be less favorable flash
flooding than the other scenario, a more directly west to east
orientation. As of now, the latest high-resolution ensemble
guidance places the axis of heaviest rainfall along to just
south of the North Dakota and South Dakota border, covering
north central and northeastern South Dakota as well as western
Minnesota. The 00-06Z time frame appears to have the best
chances for the heaviest rainfall, with most areas looking at
1-2 inches in total. The heaviest storms will have the potential
to dump as much as 2-4 inches in that 6 hour time period, and
up to 5 inches total over the 24 hours ending Wednesday morning.

By Wednesday, the front will complete its journey through the
Aberdeen forecast area, and the pattern aloft will shift to
become more zonal. As a result, temperatures will cool off
slightly through at least Thursday. Highs will be in the low to
mid 80s, which is near-normal to roughly 5 degrees below normal
for this time of year. Beginning at the end of the week, there
is a fair degree of confidence in a warming trend as a broad
upper-level ridge takes hold of the western and central CONUS.
The latest NBM guidance gives areas west of the James River a
50-70 percent chance for high temperatures to reach triple digit
Sunday and Monday as a result of the warmer airmass. Of
potential interest, the last time Aberdeen recorded a 100 degree
temperature was nearly three years ago, on July 26th, 2023.
Probabilities over the weekend of Heat Risk reaching major
status reach as high as 70-80% on Sunday and Monday, indicating
the potential for widespread heat impacts.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 638 AM CDT Tue Jul 7 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are forecast through, at least, the first half of
the TAF period. By 06Z Wednesday, sub-VFR cigs could be
developing/moving south into the region. More SHRA/TSRA are
expected across the region, starting this morning over north
central South Dakota (KMBG). As the day wears on, the convective
potential spreads further south and east to included the other
three terminals. Severe thunderstorms are possible during the
late afternoon through late evening timeframe.

&&

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

&&

$$

UPDATE...10
DISCUSSION...BC
AVIATION...10