535
FXUS63 KABR 172100
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
400 PM CDT Sun Aug 17 2025

.KEY MESSAGES...

- Marginal risk (level 1 of 5) for severe weather from south central
SD into northeast SD and west central MN tonight. Main threats are
for severe wind gusts and locally heavy rainfall.

-There is also a slight risk for excessive rainfall over
northeastern SD and west central MN into Monday morning.

- There is another marginal risk (level 1 of 5) for severe weather
over central SD and portions of northeast SD Monday. Main threats
are for severe wind gusts and hail.

&&

.DISCUSSION...
Issued at 400 PM CDT Sun Aug 17 2025

Active weather continues for part of this forecast area this
afternoon as an area of showers and thunderstorms move south parts
of our eastern zones, mainly across the I-29 corridor and points
east into west central Minnesota. The overall upper flow pattern has
remained consistent with a sprawling upper level ridge across the
central and southern Plains. Clockwise flow around this feature puts
our region a modest westerly flow with embedded s/w energy rotating
around the periphery of the ridge from the Rockies/High Plains into
the Dakotas and Northern Plains. This is expected to persist into
the early portion of the week before the ridge re-centers itself
westward closer to the Four Corners region of the southwest CONUS.
This will lead to more northwesterly flow aloft locally leading to a
period of drier conditions through the middle of the week and
warming temperatures.

The set up for tonight calls for additional convective development
across parts of northeast SD and west central MN. Sfc low pressure
remains attached to a frontal boundary located near the SD/NE border
area. This system is expected to slowly track east to northeast into
portions of eastern SD tonight and eventually into western MN by
Monday morning. Air mass destabilization will continue to occur
through the remainder of this afternoon across our eastern zones.
Some CAM solutions depict new convection developing across parts of
northeast SD/west central MN late this afternoon/early evening,
perhaps forming a line or cluster of storms which will track east
and out of our area sometime by mid/late evening. A marginal risk (1
of 5) for severe weather remain possible in these areas, mainly for
the risk for damaging winds and isolated threat for large hail.
Locally heavy rainfall will also be a concern and given the
saturated soils in our east, it won`t take much rainfall to lead to
flooding issues in those more prone areas.

This activity will shift out of our area leading to mainly drier
overnight period. Sfc high pressure moves into the area on Monday
giving most of us a break from the active weather. However, return
flow sets up across central SD in the afternoon with increasing
instability leading to a few scattered strong to severe storms
possible by late afternoon and early evening. A marginal risk for
severe weather is posted for those areas for that time for severe
wind gusts and large hail. A more quiet pattern takes hold by
Tuesday into Wednesday with temperatures gradually warming back into
the 80s and 90s.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1244 PM CDT Sun Aug 17 2025

Terminals KABR,KATY,KPIR,KMBG

MVFR/IFR cigs have been persistent at KPIR/KMBG this morning but
some slow improvements have been noted. Anticipate further
improvements with time and VFR conditions will return by later
this afternoon and tonight through the end of this TAF cycle.
Farther east at KABR/KATY, periods of scattered convection will
continue this afternoon into this evening. Potential remains for
MVFR/IFR cigs/vsby`s in heavier showers or thunderstorms during
this period of time. Looks as if KATY will see deteriorating
conditions early Monday morning with low stratus and fog leading
to a period of MVFR/IFR cigs/vsby`s. Eventually, VFR conditions
should become the prevailing conditions at these eastern terminals
by mid to late Monday morning.

&&

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

$$

DISCUSSION...Vipond
AVIATION...Vipond