682
FXUS63 KABR 031128 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
628 AM CDT Wed Jun 3 2026

.KEY MESSAGES...

- A  Slight Risk (Level 2 of 5) for severe weather is in place for
storms this afternoon and evening, mainly east of the Missouri
River. Large hail of 1-2" in diameter and wind gusts of 60 to 70 mph
are the main threats. Tornadoes will be a secondary threat, as will
flash flooding due to heavy rainfall. Areas west of the Missouri
River are under a Marginal Risk (Level 1 of 5).

- Thursday, another Slight Risk for severe weather is in effect
along and south of US Highway 12. Areas to the north of US Highway
12 are under a Marginal Risk. Large hail of 1-2" in diameter will be
the main threat, with wind gusts of 60 mph as a secondary threat.

&&

.UPDATE...
Issued at 624 AM CDT Wed Jun 3 2026

Updated for 12Z Aviation Discussion below.

&&

.DISCUSSION...
Issued at 235 AM CDT Wed Jun 3 2026

Sub-severe showers and storms are overhead early this morning, and
the expectation is that storms will continue to weaken as they move
east. Some weak showers to perhaps isolated thunderstorms will
linger through the morning, but expecting very little out of what
remains of these storms.

Focus then shifts to the severe threat this afternoon and evening.
Model guidance has trended storm development a bit to the west,
mainly along a cold front that will be passing through during the
course of the day. Storm mode will begin as discrete cells (forming
between the James River Valley and Missouri River) before turning
into a line of storms in the evening as they progress east of the
James River. Hail is expected to be the main threat, particularly
with the earlier storms. Significant hail development (2"+ in
diameter) will be possible, with 2000-2500 J/kg of CAPE, 30-40 knots
of shear, and mid-level lapse rates > 7 C/km all supportive of the
threat. Severe wind gusts will be the secondary threat, with
northeastern South Dakota being the main potential threat area with
the linear storm mode. DCAPE over 1000 J/kg will be present, along
with near-surface lapse rates of 8 C/km, supporting easier mixing to
the surface. Concern for tornadoes will also be in place, although
there is a bit more uncertainty here. Low-level shear will likely be
the main limitation here, but can`t rule anything out at the moment.
Also can`t rule out heavy rain leading to flooding either, although
this will be most prevalent while storms are in the discrete mode
early on. Once storms form the line, the chances for training and/or
slow moving storms are expected to decrease.

Another Slight Risk is in place Thursday evening, with the main
threat being over central South Dakota. Strong CAPE > 2000 J/kg will
be present in that area, along with shear of 40-50 knots. This along
with lapse rates of 7 to even 8 C/km will support severe hail as
once again being the main threat. Wind and tornado threat is less of
a concern at the moment. However, can`t quite rule out a stray gust
or two with some marginal DCAPE over central South Dakota, nor can
tornado development be entirely disregarded. At this point, the most
favorable locations for both of those hazards will be over central
South Dakota, as is the largest hail threat.

A weak upper-level ridge builds overhead late Friday into Saturday,
temporarily cutting off precipitation chances for the weekend. This
break may not last long however, as ensemble confidence remains
fairly high on another upper-level trough developing over the
western CONUS by next week.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 624 AM CDT Wed Jun 3 2026

Terminals KABR,KATY,KPIR,KMBG

Primary item of focus is the thunderstorm development this
afternoon associated with a cold front moving through the area.
Expect development to occur in central SD (around or just east
of the Missouri River) and then push east with time through the
evening. Tried to time out the potential with either the PROB30
or FM groups this afternoon/evening. Felt the most confident
with KABR and went FM group for TSRA for ~3hrs late this
afternoon. Elsewhere, there was enough uncertainty in the
development to hold off on a FM/TEMPO group at this time. Behind
the front/convection, may see some low clouds, like this morning
in southwest SD, but confidence isn`t high enough to mention at
this point.

&&

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

&&

$$

UPDATE...SRF
DISCUSSION...BC
AVIATION...SRF