268
FXUS63 KABR 150904
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
404 AM CDT Sun Jun 15 2025

.KEY MESSAGES...

- There is a Slight risk (2 out of 5) for severe thunderstorms
  across central and north central South Dakota mainly for
  thunderstorm potential later tonight. Main threat later tonight
  would be strong/damaging winds.

- There is an Enhanced risk (3 out of 5) for severe thunderstorms
  across far northeast South Dakota into west central Minnesota
  Monday afternoon. Large hail, damaging winds and a tornado or
  two are all possible severe weather threats Monday afternoon.

- Temperatures are forecast to warm to 5 to 10 degrees above
  normal by the end of the week.

&&

.DISCUSSION...
Issued at 401 AM CDT Sun Jun 15 2025

At 3 AM CDT, showers and thunderstorms are moving northeast through
the counties in the CWA that are west-river. There are two clusters
of thunderstorms of interest right now. The first is moving through
Dewey/Corson Counties while the second is down in Tripp County.
Adequate environmental characteristics; instability (600-800J/kg
hail CAPE), deep layer shear (30-40knots) and a decent outflow
boundary, accompanying a couple of mid-level shortwaves, are all
providing the potential for this early morning convection to reach
severe limits at times. This convection should continue to move off
to the northeast as the morning progresses. Short-term convective
guidance suggests more showers and storms may be able to develop
further east across the CWA between now and 18Z. PoPs are in the
forecast to account for this potential. Temperatures are running in
the 50s this morning on east-component winds around 5 to 15 mph.

Overall, the steering flow pattern through Sunday over the CONUS is
dominated by an upper level ridging pattern before upper level
longwave troffing develops late in the period. It`s a low amplitude
ridge pattern for the most part, with multiple smaller transient mid-
level shortwaves of low pressure progged to move west to east across
the region, the strongest of this impulses appearing to move through
on Tuesday/Tuesday night. The synoptic-scale pattern for the next
couple of days supports gulf moisture remaining in place over the
region, meaning surface dewpoints, at least, in the 60s over the CWA
and plenty of instability 2500+ J/kg CAPE at peak heating times
through Monday afternoon.

The SPC Day 1 outlook has the western third of the CWA currently in
a slight risk for severe weather (with an enhanced risk mainly for
wind) just west/northwest of the CWA. The next semi-discernible mid-
level shortwave appears to be heading for south central Montana at
this time. This system is expected to induce some strong convection
later this afternoon/evening out across the northern high plains
terrain of southern/southeastern Montana over into northeast
Wyoming. Over time, guidance appears to transition convective threat
from a supercell/large hail scenario to more of a MCS/strong and
damaging wind threat. And it is this wind threat that could be
running into the northwestern forecast zones later tonight (early
Monday morning) after midnight.

The SPC Day 2 outlook has the eastern and southern portions of the
CWA in a slight risk for severe weather, with an enhanced risk for
severe weather over the far eastern forecast zones. At this point,
severe weather guidance indicates that if convection were to develop
along a frontal boundary/within a surface trof draped over the
region, deep layer instability/shear would point storm mode to
supercellular. Low level severe parameters, at this time, also
support a conditional/localized tornado threat Monday afternoon
across the Prairie Coteau over into west central Minnesota.
Conditional because depending how influencing tonight/early Monday`s
convective event is, the cold front may be blown well south/east of
the CWA by Monday afternoon. Something to watch for heading into
Monday. The system that moves through on Monday has a cold front
attached to it, which is progged to scour out some of this higher
moisture content air for, at least a couple of days while surface
high pressure extends its influence down into the region. By
Thursday night, though, return flow appears to set back up, and
persist heading into the weekend.

Low level thermal progs do show a steady diet of warming conditions
underneath this ridge aloft. Although, as the past few days have
confirmed, a lot will depend on how long it takes to scour out the
fog/low clouds. That said, the fog/low clouds should become less and
less of temperature forecast factor over the next day or two with
daytime mixing/heating. Later in the period, low level thermal progs
and ensemble S.A. table temperature anomalies do indicate that some
fairly toasty temperatures are on the way for the end of the week,
into the weekend.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1231 AM CDT Sun Jun 15 2025

Terminals KABR,KATY,KPIR,KMBG

The lower clouds will remain in place over eastern SD, resulting
in an IFR forecast to start the period off at MBG/ABR/ATY. PIR is
forecast to hold on to VFR conditions through the period. ATY is
forecast to remain in IFR conditions through 14Z with lower
ceilings, and the addition of fog down to around 1SM overnight. A
lower confidence forecast remains with the timing and intensity of
nearing showers and thunderstorms early this morning. PROB30`s
mentioning tsra are in place at PIR and MBG for now.

&&

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

$$

DISCUSSION...10
AVIATION...10