Watertown, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

985
FXUS63 KABR 130714
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
214 AM CDT Wed Aug 13 2025

.KEY MESSAGES...

- Weak/isolated showers and thunderstorms will move west to
east across the area this morning into the early afternoon. Severe
weather is not anticipated with this round of moisture.

- There is a slight risk (level 2 of 5) for central/south central
South Dakota, and a marginal risk (1 out of 5) south of a line from
Mobridge to Redfield and Watertown. Main threats in these outlook
areas are large hail and winds of 60-70mph. Timing of severe weather
is mainly evening and early overnight.

- There is a slight (2 of 5) risk area for the northern tier of
northeast South Dakota, and a marginal risk (1 of 5) in central
South Dakota for storms on Thursday. Again, timing is evening to
overnight and main threats are hail and winds. Coverage is expected
to be more isolated.

- Unsettled weather patten will continue for the end of the week
into the weekend.

- Hot and humid Thursday with highs/heat index values near 100 in
central South Dakota. Temperatures will remain close to climatology
(80s in central SD & 70s in the northeast) Friday through the
weekend and into next week.

&&

.DISCUSSION...
Issued at 209 AM CDT Wed Aug 13 2025

Mid-level clouds associated with warm advection have already
developed out west. There is a very subtle shortwave evident in
deterministic 500mb analysis that will slowly traverse the forecast
area through the course of the day. That, combined with about 100-
200j/kg of mid-level instability means we can anticipate high-based
showers and weak storms to migrate from west to east through the
course of the morning and early afternoon.

The focus then shifts to this afternoon. cams indicate convective
development out west around 00Z mainly out towards the hills but
some of the cams also show some development out in the Pierre area.
CAMS show the convective cluster migrates east southeast across
primarily central South Dakota, Though a couple of the CAMS show
more isolated coverage up along the northern tier of the state into
the northeast by around midnight. CAMS also linger convection
through about 12Z Thursday morning, likely thanks to a 35-45kt low
level jet over the eastern Dakotas/Minnesota.

The 25th 75th percentile range in CAPE from the HREF is
approximately 1200 to 2500 joules per kilogram at about the time of
convective initiation. 0-6km shear runs about 40 knots with a bulls
eye of 50 knots in central South Dakota, With a majority of that
being westerly unidirectional mid-level flow with southeasterlies
in the boundary layer. Across central South Dakota LCLs will end
up running around 8000 feet With dew point depressions running
around 15 Celsius. Doesnt look like theres strong mid level drying
in these profiles, but at 95 over 60 and bases AOA 6-8kft aside
from the shear driven hail aspect, would also think winds are the
primary threat for today.

The heat and humidity is on for Thursday. NBM temperatures and heat
indexes approach the century mark in central South Dakota. Does not
appear at this time to be widespread enough to warrant a heat
advisory. CAMS and Bufkit profiles hint theres still the
potential for isolated convection to break the cap Despite the
elevated mixed layer aloft, possible aided by enhanced flow aloft
thanks to a trough to the north and ridging to the south.
Uncertain if theres a wave embedded within that flow however, but
there is a wave in the NAM/GFS and Canadian later for Friday
morning. NBM has limited POPs but there is some mid level
instability (1200 j/kg in NAM BUFKIT) to support elevated
convection. The heat on Friday is also undercut by a backdoor cold
front.

The rest of the forecast is off and on again chances for moisture as
the pattern is overall unchanged until we get into the middle of
next week with a 4 corners ridge expected to build and project into
the northern Rockies.


&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1211 AM CDT Wed Aug 13 2025

Terminals KABR,KATY,KPIR,KMBG

VFR conditions for all terminals through the day. Elevated
thunderstorms are possible this morning, but too low a probability
for inclusion in TAFS. Later, after 00Z there are higher
probabilities for storms.


&&

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

$$

DISCUSSION...07
AVIATION...07