050
FXUS63 KABR 172313
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
613 PM CDT Wed Jul 17 2024

.KEY MESSAGES...

- 20 to 40% chance of precipitation Friday afternoon and evening,
with the highest chances across central South Dakota.

- High temperature will range between normal to a few degrees below
normal Friday through the weekend.

&&

.UPDATE...
Issued at 610 PM CDT Wed Jul 17 2024

No changes to the forecast with the last of daytime cumulus
dissipating with loss of heating.

See below for the update to the Aviation discussion.

&&

.SHORT TERM /THIS EVENING THROUGH THURSDAY NIGHT/...
Issued at 222 PM CDT Wed Jul 17 2024

Our weather will continue to be dominated by the surface high
currently set up over southern Manitoba and eastern ND/northwestern
MN. At 500mb the forecast area remains in between the high amplitude
ridge originating from the 4-corners region through much of western
Canada, and the trough across much of the eastern U.S. We will be in
between the 2 areas, with northwesterly flow continuing at 500mb.

As we move into the overnight hours, the surface high will continue
to sink south-southeast and moving to IA by 15Z Thursday. The
elongated surface trough to our west will slowly near western SD
during the daytime hours Thursday. While mainly dry conditions are
expected to continue through the period, isolated showers or
thunderstorms (less than 25% chance of precipitation) will be
possible Thursday night over portions of central SD.

Winds will be increasing Thursday, out of the south to southeast
Thursday afternoon with gusts around 20mph over central SD. Fire
weather concerns remain limited thanks to recent rain over the past
week and relative humidity values at or above 35 percent.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 222 PM CDT Wed Jul 17 2024

Friday morning starts the long term with a shortwave coming down
from northeast MT, riding the upper level ridge. This will move
southeast into the region Friday evening. Some models show a second
area of vorticity following close behind. The first area moves south
into NE/IA Saturday afternoon and then moves in a more easterly
direction. The second moves almost directly south Saturday afternoon
and then in a south southwest direction during the day Sunday. These
two areas of low pressure will effectively bend the ridge around our
area, leaving us in generally north to northeast flow aloft. Models
are somewhat conflicted on how much deep layer moisture there will
be Friday and Saturday. The GFS is leading the charge with a good
bit of moisture on both days and also some higher precip chances
over our area on Friday. Down at 850mb, there is a lot more
widespread moisture as the pattern brings up Gulf moisture. However,
there doesn`t seem to be much forcing to cause a lot of rainfall.

On the topic of rainfall, some chance PoPs (30 to 50%) spread across
central and northeast SD overnight Friday into Saturday morning.
Highest PoPs are west river. NBM is showing accumulations to be less
than a quarter of an inch (chance of more than a quarter inch is
less than or equal to 20%) however, there is room for change in this
forecast. There is also a chance of some storms Friday. SPC has a
marginal (1 of 5) risk for severe storms west river. Hazards with
any storms that become severe would be mainly strong winds but
some large hail could form in more isolated cells. Some additional
chance PoPs (around 40%) move in overnight Saturday into Sunday
morning as well with expected accumulations less than a quarter
inch. Some slight to low level chance PoPs (less than 25%) stick
around through the end of the period.

Temperatures will be around to slightly below average for most of
the period, warming up to slightly above average for Wednesday.
Winds will be shifting directions from southerly to northerly and
back from Friday to Monday but are not expected to be overly strong
at any time.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 610 PM CDT Wed Jul 17 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions for all terminals.

&&

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

$$

UPDATE...Connelly
SHORT TERM...KF
LONG TERM...KK
AVIATION...Connelly