147
FXUS63 KABR 192345 AAA
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
645 PM CDT Fri Jun 19 2026

.KEY MESSAGES...

- There is a Marginal Risk, level 1/5, for isolated severe
  storms this evening over northeastern Roberts County in SD
  through west central Minnesota. Main threats will be hail of
  1" in diameter and wind gusts of 60 mph. Weak cold air funnels
  or a landspout is also a possibility.

- Widespread rainfall is expected Saturday evening through
  Sunday evening focused across central South Dakota.
  Probability of rainfall of 1" or more through Monday is 65-90%
  along and south of a line from Eagle Butte to Fort Thompson,
  highest over south central SD.

- Temperatures remain near to slightly below normal through next
  week. Coolest day being Sunday at 10 to 20 degrees below
  normal.

&&

.UPDATE...
Issued at 634 PM CDT Fri Jun 19 2026

The aviation discussion has been updated for the 00Z TAFS.

&&

.DISCUSSION...
Issued at 203 PM CDT Fri Jun 19 2026

As of 1pm, the center of the positive tilted shortwave is hovering
over the ND/MN border with the center of its low over northern
MN/ND/Canadian border and cold front extending along the Dakotas and
MN border. Satellite indicates cumulus clouds moving in from the
northwest over north central and northeastern SD/western MN with
showers and thunderstorms ongoing near the low/front over ND/MN
border. Cams indicate ongoing heating (ML Cape is currently 200-500
j/kg) could lead to vertical growth resulting in spotty
thunderstorms developing (or moving in from ND) over our far
northeastern CWA later this afternoon through the early evening.
There is a Marginal Risk, level 1/5, for isolated severe storms over
northeastern Roberts County through west central MN during this
time. Main threats will be hail, up to 1" in diameter, and 60 mph
wind gusts. Low and mid level lapse rates are steep with Hail Cape
between 300-500 j/kg and inverted V soundings which lead to these
threats. Of note, SPC meso parameters also indicate surface
vorticity overlapping with 0-3km ML Cape of 100-200j/kg suggesting
cold air funnels or landspout could possible through this evening.
As of 1830Z the best overlap and NST parameter of 1-2 is near the
low/boundary along the ND/MN border. The positive tilted shortwave
will continue to track southeast through this evening, with the axis
over MN/WI at 00Z. The surface high pressure system will move in
over the region keeping the area dry tonight and keeping conditions
dry over north central SD through the morning and northeastern
SD/western MN through Saturday evening as the high tracks eastward
over ND/Canada and into MN.

Our attention then turns to this weekend where widespread rainfall
is forecast with the focus across central SD, especially south
central SD. Another shortwave and its embedded pulses will track
west to east across the Central Plains and northward through SD
early Sunday through early Monday. At the surface, an elongated area
of low pressure will extend from the Northern Rockies through the
central Rockies Saturday with several lows lying along a the
boundary. Within this, a Colorado Low develops Saturday evening,
with a secondary low developing and tracking across the Central
Plains Sunday into Sunday evening. As what the previous shift
mentioned, the rain will be more elevated and stratiform per this
shortwave and less surface based/convective as the region will be
north of this Co low/surface boundary and east of the lows/boundary
over the Rockies.

Ensemble models overall agree on precip tracking northward from the
Central Plains and moving in over south central SD Saturday
midday/afternoon. The rain continues to track northward over
central/north central SD through Saturday evening and becoming
widespread and covering much of central SD and portions of
northeastern SD by Sunday morning. Far northeastern SD/western MN
will either see very light rain or nothing as the high will keep
conditions dry. If the high drifts further south, then the cutoff
will be more southwest of here and vice versa. The last of the rain
is forecast to exit the southeastern CWA by Sunday night/early
Monday. The bulk of the precip will be 00Z Sunday-00Z Monday with
NBM pops of 40-95%, highest over south central with pops diminishing
the further northeast you go in the CWA. PWAT values (with the
exception of far NESD/MN) are on the order of 1-1.4" highest over
south central SD. This is above the 90th percentile here, per
ensemble mean, and around 2 standard deviations above climo per
NAEFS. NBM probability of 48hr rainfall>1", ending 12Z Monday is 65-
90% along and south of a line from Eagle Butte to Fort Thompson,
highest over south central SD. Probability of 2" is 40-55% over
south central SD. Due to this, the WPC has put central SD in a
Slight Risk, which is a 15% chance exceeding flash flood guidance.
The 25-75th spread ranges from 0.3 to 1.3" along and west of a line
from Aberdeen to Redfield. The high spread is due to the exact track
of low and how much this high pressure system influences rainfall
north and northeast of south central SD. Any track north or south of
the system will impact where the heaviest rainfall will occur. As
for convection, it will be low cape/"high" shear as MUCAPE0.25" per NBM is 55-70% along and north of a line from Aberdeen
to Ortonville and highest over far NESD/MN. Daytime heating and
mixing will lead to the chance of thunderstorms in the afternoon and
evening. As of now, no severe weather is anticipated. Behind this
low/shortwave, a ridge builds over the western CONUS and its high
over the Southwest as the CWA remains in northwest flow. This will
push eastward and over the region by the end of the week. Exact
amplitude of this wave is unknown at the time given this is several
days out as NAEFs indicates it becoming lower in amplitude as it
tracks east. Moisture chances return for the end of the week with
general pops of 20-40%.

Highs for Saturday, per east/southeast flow and ridge aloft, will
range in the mid to upper 70s. Cooler on Sunday due to rain and low
clouds with highs in the 60s and 70s, coldest over central SD.
Monday-Wednesday will remain in the lower to mid 70s and mid to
upper 70s for the end of the week, with the possibility of some 80
degree readings on Friday.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 634 PM CDT Fri Jun 19 2026

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are expected to prevail at all terminals through
this forecast cycle. Gusty north to northwest winds early this
evening should quickly diminish by mid evening. Light and
variable winds overnight will become east to southeast on
Saturday morning and turn gusty at KPIR/KMBG in the afternoon.
Precipitation chances will begin to increase toward the end of
the day across south central SD. Included a PROB30 group in the
KPIR forecast for -SHRA potential late in this TAF valid period.

&&

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

&&

$$

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