195
FXUS63 KABR 110452 AAB
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1152 PM CDT Sat Aug 10 2024

.KEY MESSAGES...

- Temperatures will continue from 5 to 15 degrees below average
  through the weekend.

- There is a 30-80% chance of showers and thunderstorms from early
  Sunday through early Monday, with the highest chances of
  precipitation over central South Dakota Sunday afternoon.

- A general warming trend is expected with seasonal/near average
  temperatures for the later half of next week. Weak systems next
  week will provide for off and on chances for moisture.

&&

.UPDATE...
Issued at 1147 PM CDT Sat Aug 10 2024

Updated for the 06Z Aviation discussion below.

UPDATE Issued at 608 PM CDT Sat Aug 10 2024

Updated for 00Z Aviation discussion below.

The going forecast looks to be in good shape, as high pressure
continues to influence the weather over much of the area. Expect
the diurnal cu to continue to diminish over the next hour or two,
but high clouds will spread from west to east over much of the CWA
from convection in MT/WY that is moving east.

&&

.SHORT TERM /THIS EVENING THROUGH SUNDAY NIGHT/...
Issued at 130 PM CDT Sat Aug 10 2024

At 1 PM CDT, skies are mostly sunny and temperatures are warming
through the 70s. Winds are light and variable with the axis of
surface high pressure fixed over the CWA.

There is low pressure organizing out over the Pacific Northwest,
which will push across the northern plains tomorrow. Initially, PoPs
show up across all of the west-river zones late tonight through
Sunday morning where all the forcing/lift will line up with a lee-
side/inverted surface trof over the western Dakotas. Heading into
Sunday night, the best forcing/lift begins shifting down across the
southern half of South Dakota, and the PoPs appear to be trending a
bit in that direction as well. There is a marginal risk for severe
thunderstorms down across Stanley/Jones/Lyman counties Sunday
afternoon/evening closer to a surface low reflection where the best
available instability (~500-750J/kg) and deep layer shear (30-40
knots) over this CWA will reside.

Minimal low level thermal advection occurring over this CWA in the
short term period. But, low level moisture advection is progged
across the western forecast zones, in particular, by late tonight
through the day on Sunday. Worth a mention, since there is already
quite a bit of stratus covering a lot of Kansas and Nebraska where
the higher amounts of low level moisture are analyzed. Expecting an
increase in low/mid cloudiness heading into Sunday across the
Missouri River valley (the western) portion of the CWA, which should
hold temperatures down a bit across that area.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 130 PM CDT Sat Aug 10 2024

At the start of the period, shortwave energy will be departing to
the east on Monday, while high pressure at the surface moves over
the region. Ensemble output still hinting at some precip potential
during the morning hours on Monday as the mid-level disturbance is
departing. GEFS/ENS/GEPS probs for at least .01 QPF (6-hourly) show
about 30-50% across the eastern CWA during the day Monday. Inherited
NBM PoPs do show slight chances (20%) in the far southeast corner of
the CWA, and see no reason to change this for the time being.

Upper pattern then takes on more of a ridging look across the
central/northern plains area into Wednesday, before shortwave energy
crosses the region potentially mid-week. Cluster analysis shows
there is some subtle differences in just how much this shortwave
will flatten the ridge across the Northern Plains, which in turn is
telling to the overall strength of the shortwave as well. That said,
this looks to be the first good chance (30-60%) for rainfall Tuesday
night into Wednesday. Taking a glance at CSU-ML for Day 5, and it
does highlight a 5-15% potential for severe storms over
central/western SD.

As for temperatures, with the broad upper ridging trying to build
into the plains states, temperatures will be a bit warmer than what
we`ve been experiencing lately. Highs should rebound back into the
upper 70s and 80s by mid-week and beyond.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1147 PM CDT Sat Aug 10 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will prevail for much of the TAF period, as dry low
level air from the slowly departing high continues to remain over
the area. Over central SD, a low pressure trough will move into
the area on Sunday morning and be the focus for some shower and
potential thunderstorms from late morning through early evening.
The best chance for showers is at KPIR, so they continue to show
the showers in the TAF. Will need to watch that area for stronger
storms and potential addition of thunder to the TAF.

&&

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

$$

UPDATE...SRF
SHORT TERM...Dorn
LONG TERM...TMT
AVIATION...SRF