126
FXUS63 KABR 100733
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
233 AM CDT Sat Aug 10 2024

.KEY MESSAGES...

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

- There is a 40-65% chance of showers and thunderstorms Sunday
  through early Monday, with the highest chances of precipitation over
  central South Dakota.

- 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.

&&

.SHORT TERM /TODAY THROUGH SUNDAY AFTERNOON/...
Issued at 233 AM CDT Sat Aug 10 2024

As of 2am overall skies remain clear with some mid to high
clouds passing over central SD. Temps are ranging in the upper 40s
to the lower 50s. Short term models indicate northwest flow over the
Northern Plains as the large low continues to push east/northeast.
The center of the low is forecasted be over eastern Ontario/western
Quebec by early Sunday morning. The low amplitude ridge out west
will also break down Sunday, with winds turning more
zonal/northwest, as shortwaves move in over the Northern Rockies
Sunday morning. These waves will push east and over the Northern
Plains through the day. At the surface, a high pressure still
remains dominant which will keep the area dry for today. This high
shifts a bit east for Sunday with the incoming waves.

850mb winds become southeasterly early Sunday morning, ushering in
WAA and an increase in moisture, seen on RAP 1000-500mb RH over
north to south central SD. With aid from the shortwaves, HREF/RAP
indicates elevated showers and thunderstorms moving into this area
during this time. CAMs seem to show this but there are some
differences between the models on timing/location as they enter our
western CWA. Precipitation will spread eastward through Sunday
afternoon over central and parts of northeastern SD. Pops range from
30-65%, highest over south central SD. Instability looks to remain
low as MUCAPE values will be under 1000 j/kg over central SD,
however, 2-5km UH>75m2s2 indicates the possibility of some stronger
cells skirting our southwestern CWA Sunday afternoon as shear will
increase to 30-40kts in this area. Lapse rates will be marginal and
these are the HRW models showing this and may be a bit aggressive.

With east to southeast flow over central SD today, temps will be
warmer at 850mb, around 15-16C in this area, with cooler temps (from
high) over our eastern CWA ranging from 9-13C. Surface highs are
forecasted to range in the 70s to possibly 80, warmest around and
west river. With WAA continuing tonight, lows will not get as
chilly, ranging in the 50s (few upper 40 readings possible along
ND/SD border). Highs for Sunday will again range in the 70s but will
be cooler over the western CWA than today due to cloud cover.

&&

.LONG TERM /SUNDAY EVENING THROUGH FRIDAY/...
Issued at 233 AM CDT Sat Aug 10 2024

Upper flow pattern has us in between two weak troughs through most
of the extended. Late week, deterministic members diverge in
handling how the upper trough to the west migrates into the center
of the country, so will focus in the interim. Monday through Thursday
we will have a ridge aloft, though with several weak waves migrating
through the flow. In the low levels, the broad expanse of the high
pressure continues to dominate the Midwest with easterly low level
flow off that high keeping us mild with relatively/seasonally low
dewpoints. We do see a weak low level jet slowly pulling 850mb
moisture northwards, but this round of the GFS shows a much less
organized plume with a low to the south disrupting this moisture
feed until mid-week.

So for temperatures, its a slow steady incline to seasonal normals.
No major blobs of low level warm air, and even the GFS`s temporary
depiction of an elevated mixed layer late Tuesday is not depicted
as nearly as strong in the EC/Canadian.

For precipitation, NBM is producing rather continuous POPs though the
extended with few breaks. This is more a representation of a low
confidence forecast as after Sunday, numerous GEFS members also show
on and off low QPF values smattered across the course of the week.
The NBM`s probabilities for 0.01" 24 hour QPF is roughly 30 percent
just about every day, though with higher probabilities for higher
values of QPF for the Wed/Thurs timeframe when the upper wave over
the Pacific Northwest begins to migrate into the Rockies.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1212 AM CDT Sat Aug 10 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions expected through the TAF period along with light
winds out of the east and southeast around and west of the
Missouri River and winds more northwest over northeastern SD
today. Winds across the area will shift easterly tonight turning
southeasterly Sunday afternoon.


&&

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

$$

SHORT TERM...MMM
LONG TERM...Connelly
AVIATION...MMM