Spink Colony, South Dakota Weather Forecast Discussion

274
FXUS63 KABR 161737 AAC
AFDABR
Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1237 PM CDT Tue Sep 16 2025
.KEY MESSAGES...
- There is a Marginal risk (threat level 1 of 5) for severe storms
  this afternoon and evening across south central SD and into
  portions of northeast/east-central SD. Main threats are winds
  around 60 mph and quarter size hail.
- A prolonged period of wet weather is expected Wednesday and
  Thursday, with most of the rain slowly coming to an end Friday
  into Friday night. Moderate rain over the same area could create
  flooding issues.
&&
.UPDATE...
Issued at 1233 PM CDT Tue Sep 16 2025
Aviation discussion updated below for the 18Z TAFs.
UPDATE Issued at 1024 AM CDT Tue Sep 16 2025
Seeing an uptick of showers/thunderstorms recently across the
southeast CWA, with continued activity across Lyman/Jones
counties. Have therefore adjusted PoPs to better match current
radar trends and expectations. Otherwise, no major changes to the
forecast for today with the frontal zone being the focus for
convection later today, although with doubts on the overall
coverage of said activity.
&&
.DISCUSSION...
Issued at 423 AM CDT Tue Sep 16 2025
The early morning surface weather map showed a 1014mb low centered
over our forecast area with a deeper 1010mb low over eastern CO .
Northwesterly winds were set up on the back side of the low (over
central SD), with winds still out of the south to southeast across
eastern SD and western MN. The showers and thunderstorms that moved
near the MO River around 06Z have since diminished in intensity and
coverage, with only a few showers lingering from Eureka through
Gettysburg and Lyman County as of 840Z. As the showers continue east
they will get into less favorable air. However, there are additional
showers and storms over northern NE and south central SD that will
result in at least a 20% chance of precipitation in the forecast for
our far southwestern counties through 12Z.
The eastern CO low will track east, with a trough set up from
eastern SD through western KS by 00Z Wednesday, allowing for a
conveyor belt of moisture to surge north. There is a marginal risk
of severe weather ahead of the low, for portions of south central to
northeastern SD and west central MN. This will be for late
afternoon, mainly after 22Z with precipitation over south central SD
that will be shifting northeast across the rest of the area. The
NCAR medium-range real-time convective hazard forecasts have
highlighted this area as a concern for the past several days. Still,
there is some significant uncertainty on how far northeast the
stronger storms will be able to make it this evening. Even one of the
most robust CAMs, the NAM Nest keeps convection south of US Highway
212 and mostly south of US Highway 14. A few strong to severe storms
will be possible late this afternoon through this evening.
More steady rain, and a few embedded thunderstorms, can be expected
by late Wednesday morning. This is when our chance of precipitation
increases to 60-80%. While there will be breaks from the rain, the
off and on precipitation may result in localized flooding issues.
There is a 40-70 percent chance of getting an inch of rain by
Friday, and around a 20-40 percent of getting over 2 inches of rain.
At this time, the highest amounts/highest chances of over 1 or 2" is
expected over northeastern SD and western MN. We remain in a WPC
marginal risk area of at least 5% risk of rainfall exceeding flash
flood guidance within 25 miles of a point over much of our area
Wednesday through Friday.
The surface low will shift from over the forecast area Thursday to
our north late Friday into Saturday. Friday will be our transition
day, with the more steady rain coming to an end as drier air takes
hold. Expect dry weather over central SD Friday night through at
least Tuesday. The forecast is a little trickier for northeastern SD
and western MN as the low lingers nearby, and a 15-30 chance of rain
during the day Saturday.
Temperatures today will top out in the low to mid 80s, and in the
60s to low 70s Wednesday through Friday. Low temperatures will
remain in the 50s to low 60s through Friday, lowest over central
South Dakota.
&&
.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1233 PM CDT Tue Sep 16 2025
Terminals KABR,KATY,KPIR,KMBG
SHRA/TSRA will be on the increase in areal coverage across the
region tonight and through the day Wednesday. MVFR/IFR VSBY
possible in heavier downpours. CIGs are forecast to gradually drop
to MVFR towards the end of the TAF period as well, especially over
central SD (KPIR/KMBG).
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
&&
$$
UPDATE...TMT
DISCUSSION...06
AVIATION...TMT

NWS ABR Office Area Forecast Discussion