740
FXUS63 KABR 241724 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1224 PM CDT Fri May 24 2024

.KEY MESSAGES...

- Showers and a few thunderstorms will persist for some areas
  today(30-70%) with rain chances diminishing southwest to northeast
  during the afternoon hours.

- Cooler temperatures will be ushered in on strong west to northwest
  winds today. Peak gusts will reach 45-50 mph in portions of central
  and northeast South Dakota this morning through the afternoon where
  a Wind Advisory has been posted.

- The unsettled weather pattern continues with chances of showers
  and thunderstorms Saturday night/Sunday (35-70% chance) and Monday
  25-35% chance) before things dry out for much of the rest of the
  forecast.

&&

.UPDATE...
Issued at 1013 AM CDT Fri May 24 2024

Adjusted the timing of the wind advisories earlier this morning
with areas along the Missouri River already gusting 50 to 60 mph.
KPIR seems to be getting some enhancement off the river with the
strongest wind gusts in the region. Considering expanding the
advisory farther east, but will wait to see how the winds develop
eastward through the morning.

&&

.SHORT TERM /TODAY THROUGH SATURDAY AFTERNOON/...
Issued at 424 AM CDT Fri May 24 2024

The main focus in this period will be the exiting precip chances
today along with the increasing west to northwest winds that will
set up as low pressure spirals and spins east to northeast out of
the forecast area.

Early this morning, we continue to see showers shift north-
northeastward along and out ahead of a sfc cold front that is
working through the James Valley. This precip has been mostly in the
form of rain showers since the midnight hour, but a few weak storms
will be possible across northeast SD and west central MN through the
morning hours. We also expect another area of showers to curl into
our western zones later this morning. Associated with the mid lvl
low, this area of showers will shift west to east and then northeast
with time during the daytime hours. A few weak storms will also be
possible later this afternoon across our northeast zones as the mid
level disturbance rotates into eastern ND. Cold air advection on the
backside of this system will lead to a rather cool day today. 850mb
temperatures drop to around zero across at least the northern half
of the forecast area by midday through the late afternoon. Highs
will likely only warm into the low to mid 60s which is close to 10
degrees below normal in some areas for this time of year.

The combination of the cold air advection and a 6-8mb pressure
bubble shifting west to east across the forecast area this morning
through the afternoon will lead to an increasing west to northwest
wind from west to east. 1/2km winds are progged to increase to
around 40kts West River by early-mid morning and then shift
northeast toward the Leola Hills toward midday and afternoon. NBM
probabilities for wind gusts reaching or exceeding 45mph are in the
50-80 percent range across central SD. BUFKIT profiles indicate 40-
45kts mixing down across central and parts of northeast SD. Based on
these factors, have issued a Wind Advisory starting first across our
West River zones early this morning. East river zones up to but just
west of the James Valley get in on these advisory level winds closer
to midday. By late this afternoon and early evening, we should begin
to see improving conditions as winds gradually diminish.

A weak sfc ridge passes across the area tonight. Clear to partly
cloudy skies and cool temperatures will settle in overnight with
readings bottoming out in the upper 30s north to the low to mid 40s
elsewhere. This high will shift quickly east on Saturday as a
warm front nudges into SD associated with the next lee of the
Rockies low pressure that`s progged to develop. Mainly dry
conditions with warm advection returning will boost temps back
closer to normal with low to mid 70s for highs. By late in the
period, we will have to keep an eye on trends for the potential
for storms to return to parts central SD.

&&

.LONG TERM /SATURDAY EVENING THROUGH THURSDAY/...
Issued at 424 AM CDT Fri May 24 2024

As the longwave trof over the western CONUS, at the start of the
period, gradually gets replaced by an upper level ridge, the
remaining pieces of shortwave energy will be redirected eastward
across the nation`s mid-section (clusters analysis). Two of these
pieces of shortwave energy are progged to move across South
Dakota/Nebraska Saturday night through Monday before the upper level
ridging kicks in (NBM PoPs of 20-55% through said period). Dry
conditions appear to be in the offing for Monday night through
Thursday while this upper level ridge moves east and longwave
troffing ensues behind it over the western CONUS. With height falls
noted Thursday and Friday, and a surface pressure pattern shift to
return flow southerly winds, precipitation chances pick back up (20-
45% NBM PoPs) by Thursday night into Friday.

After Monday, near normal temperatures are anticipated (NAEFS/ECMWF
S.A. Table 850hpa thermal anomalies roughly between -0.5 and +0.5 of
"climatology"), which means highs generally in the 70s and lows in
the upper 40s to low 50s.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1222 PM CDT Fri May 24 2024

Terminals KABR,KATY,KPIR,KMBG

MVFR cigs will slowly break up and improve to VFR by 0z at all
sites. Strong northwest winds with gusts of 40 to 50 kts will
diminish early this evening.

&&

.ABR WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory until 7 PM CDT /6 PM MDT/ this evening for
     SDZ003>005-009-010-015>017-033>037-045-048-051.

MN...None.
&&

$$

UPDATE...Wise
SHORT TERM...Vipond
LONG TERM...Dorn
AVIATION...Wise