-- Discussion containing changed information from previous version are highlighted. --
170
FXUS63 KABR 160515
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
1215 AM CDT Mon Sep 16 2024

.KEY MESSAGES...

- Warm temperatures will continue through Thursday before cooler
  air returns late in the week.

- Next round of showers and storms late tonight into early
  Monday (20 to 35 percent chance), mainly across central South
  Dakota.

- Multiple chances for precipitation will persist through most
  of this week. Highest chances will arrive Tuesday night and
  continue through midday Wednesday with a 50 to 80 percent
  chance for showers and storms.

&&

.UPDATE...
Issued at 633 PM CDT Sun Sep 15 2024

The forecast remains on track this evening. No major changes are
planned.

&&

.SHORT TERM /THIS EVENING THROUGH MONDAY NIGHT/...
Issued at 314 PM CDT Sun Sep 15 2024

The region will be between an upper level ridge over the eastern
part of the country, and a deep trough over the west coast. This
will keep southwest flow over the Northern Plains, with just some
weak shortwave energy tracking across the western and central part
of South Dakota late tonight through Monday night.

At the surface, will see some shower and thunderstorm development
late tonight into early Monday morning across mainly central South
Dakota along a boundary associated with low pressure over Wyoming.
Will see some instability, (MUCAPE of 1000-1500 J/kg) across the
southwestern part of the CWA late tonight, along with 25 to 35 knots
of bulk shear. Less impressive values will extend north into north
central South Dakota. Cannot rule out a strong to severe storm or
two, but widespread severe weather is not expected. The daytime
period on Monday looks to be dry, then will see another boundary set
up over the area Monday night as the low shifts slightly northward
from Wyoming to Montana. Minimal instability and shear will likely
just mean the potential for some showers and a few non-severe
thunderstorms during the nighttime hours, mainly across the central
and eastern parts of the CWA.

Low temperatures tonight will be in the mid 60s. High temperatures
on Monday will be in the mid 80s to lower 90s. Lows Monday night
will be in the mid to upper 60s.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 314 PM CDT Sun Sep 15 2024

Tuesday morning, the area is in between 2 upper level lows. One on
the west side of the Rockies over the NV/UT/ID border and the other
over the Carolinas. This puts us in a blocking pattern for a few
days. The western low moves north northeast into WY/MT and then into
Canada by Thursday morning. However, the fronts with the surface low
of this system will move in a more easterly direction and move
across our area Wednesday and Thursday. Back up in the upper levels,
another low makes its way onto the Pacific coast of California
Thursday evening which will keep us in the blocking pattern.
Deterministic EC and GFS are very similar in this time fram and show
this low moving across the desert southwest and move up through
NM/CO and northeast into our region for Saturday night and Sunday.
The surface level low will arrive a little sooner, more like
Saturday morning and move east into Sunday. Ensembles are also in
agreement on a low in the area during this period but aren`t set on
an exact track.

Tuesday starts the period with some slight (20-25%) rain chances
east of the James River which will move east through the day. Not
much is expected out of these chances. What looks to be the best
chance for rain during the long term starts early Wednesday morning.
A band of 60-80% chances move west to east across the forecast area.
The highest chances (70-80%) look to stay south of Hwy 14 (a little
farther north than previous forecasts). These showers, and possibly
storms will move out of the area during the afternoon/evening hours.
NBM shows greater than a 50% chance for more than 0.25" mainly south
of Hwy 14. Thursday night into Friday morning also looks to have
some showers with around 30% chances over much of west central MN
and James River Valley. Another round of about 30-40% chances moves
in Friday evening lasting through Sunday when chances start to
decrease. Accumulations for the first 24 hours have a 50-60% chance
of exceeding 0.25" east of the Missouri River.

Temperatures through the period will be slowly decreasing back to
around normal for this time of year. Tuesday will be the warmest day
with highs in the mid 80s to around 90 degrees. Wednesday will
start the decent from mid 80s to upper 60s by Sunday. Tuesday is
still expected to be windy with gusts of 30-40 mph. High elevation
areas may experience these gusts again on Wednesday as well. The
rest of the period looks to have gusts under 25 mph.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
-- Changed Discussion --
Issued at 1213 AM CDT Mon Sep 16 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions are anticipated for all terminals. Showers and
isolated storms associated with a wave out west could affect
KPIR/KMBG...but confidence is low with respect to actually seeing
a thunderstorm on station and for now are precluded from the TAFS.
-- End Changed Discussion --


&&

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

$$

UPDATE...Wise
SHORT TERM...Parkin
LONG TERM...KK
AVIATION...Connelly