Watertown, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

209
FXUS63 KABR 041143
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
643 AM CDT Fri Apr 4 2025

.KEY MESSAGES...

- A wintry mix of mainly rain and snow is expected today into the
early evening hours. Look for snow accumulations of up to 2 inches,
highest over McPherson, northern Brown, and Marshall Counties.
Pockets of light icing will be possible this morning (mainly over
northern SD).

- Temperature 5 to 20 degrees below normal for early April today,
Saturday and Monday. Warmup for latter half of next week, with
temperatures 5 to 15 degrees above normal.

&&

.SHORT TERM /TODAY THROUGH SATURDAY AFTERNOON/...
Issued at 409 AM CDT Fri Apr 4 2025

The 09Z weather map showed a trough set up mainly just west of the
Missouri River. Mid to high clouds have overspread the area, with
radar reflectivity returns over at least half central SD. Surface
temperatures range from 29 degrees across portions of west central
MN to 41 degrees over our southwestern counties. The warmer air, and
highest chance of rain through the period will stay over our
southwestern counties today.

Mainly snow has been seen on webcams in Corson County so far, but
the rain/snow line isn`t too far east. The surface trough will shift
to eastern South Dakota this morning. Total precipitation through
this evening is expected to range from around 0.05 to 0.35 inches.
The lightest precipitation, and coldest air will be over north
central South Dakota, where snow will be the dominant weather type.
A glaze of light icing from freezing rain will be possible this
morning, mainly near the North Dakota and South Dakota border
between the Missouri River and James River. Snowfall amounts of
around an inch or less can be expected through early evening, with
higher amounts of around 1 to 2 inches over McPherson, northern
Brown, and Marshall Counties. Behind the area of low pressure, winds
sill shift from out of the south to out of the north and increase.
Gusts of 25 to 35 mph will occur over central South Dakota. This is
where relative humidity values will fall to 30 to 40 percent. Fire
weather concerns remain low at this time due to the precipitation
over the last few days.

Precipitation will come to an end this evening as dry high pressure
will then settle across the Northern Plains through Saturday.
Relative humidity values will fall into the 20 to 30 percent range
across central South Dakota Saturday afternoon, with wind gusts
topping out around 20 to 25 mph across the entire forecast area.

&&

.LONG TERM /SATURDAY EVENING THROUGH THURSDAY/...
Issued at 409 AM CDT Fri Apr 4 2025

Cold Canadian high pressure starts out overhead shifting southeast
across the Central Plains.  850mb temperatures are initially, un-
anomalous, and we do see some milder temperatures aloft sneak into
the region ahead of an extremely subtle 500mb wave rounding the
upper trough over eastern Canada. The result is a weak clipper over
the Great Lakes, with the subtle tail end of a cold front stalled
over South Dakota. This is really just the separation between highs,
as another Canadian high pressure system moves down into the
Dakotas/Minnesota for early next week. 850mb temperatures then dip
to a standard deviation below climo, albeit just barely and briefly,
Monday.

Thereafter we see a ridge develop between western and eastern CONUS
upper troughs before the next wave breaks into the Northern Rockies
Tuesday.  The flow thereafter becomes more zonal, with weak systems
pushed across the Northern Rockies and ejecting out into the
Dakotas/Minnesota while remaining generally weak. This results in a
modest warm and cool air push and low chances for moisture with
overall low predictability for the latter half of the work week
before we see ridging building back across the Rockies.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 643 AM CDT Fri Apr 4 2025

Terminals KABR,KATY,KPIR,KMBG

VFR conditions remain at ATY and ABR, with MVFR ceilings and light
rain at MBG and PIR. This band of precipitation will get to ABR
shortly before or after 12Z with MVFR to IFR conditions continuing
through much of the daytime hours today. Precipitation chances
will diminish behind the surface trough, with VFR conditions
returning at all locations by 02Z05, and late afternoon over
central SD.

&&

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

$$

SHORT TERM...06
LONG TERM...07
AVIATION...06