523
FXUS63 KABR 070811
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
311 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.

&&

.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 drawback 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 strongest 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 /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1238 AM CDT Tue Jul 7 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are forecast through much of the TAF period. By
06Z Wednesday, sub-VFR cigs could be developing/moving south
into the region. The last of the convective potential tonight has
cleared the KATY terminal. But, another round of SHRA/TSRA are
expected across the region, starting Tuesday morning and mainly
at/near the KMBG terminal. 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.

&&

$$

DISCUSSION...BC
AVIATION...10