616
FXUS63 KABR 120531 AAC
AFDABR

Area Forecast Discussion...UPDATED
National Weather Service Aberdeen SD
1231 AM CDT Sun May 12 2024

.KEY MESSAGES...

- Another relatively mild and dry day Sunday (Highs about 10F above
  normal).

- Low chances for showers/weak thunderstorms Sunday night/Monday in
  western and central South Dakota.

- Precipitation chances return to the area early Tuesday
  morning through Wednesday evening (30-70% chance).

&&

.UPDATE...
Issued at 1228 AM CDT Sun May 12 2024

See updated aviation discussion below.

UPDATE Issued at 842 PM CDT Sat May 11 2024

The current forecast is doing fine. No changes planned. The
approaching weak cold front is up over North Dakota. It is
forecast to be roughly mid-way through South Dakota by 12Z Sunday,
with that just slightly cooler airmass expected over the CWA
during the day Sunday.

&&

.SHORT TERM /THIS EVENING THROUGH SUNDAY NIGHT/...
Issued at 215 PM CDT Sat May 11 2024

A weak front will cross the Dakotas tonight and early Sunday. Not
much for thermal advection, just a wind shift as the storm track
remain under the influence of this northwest flow regime and the
associated wave is way up in eastern Canada.  Another northwest flow
wave crosses the region late Sunday early Monday for some low
chances for moisture. Soundings just show some mid-level moisture
and limited instability.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 215 PM CDT Sat May 11 2024

Ensembles are in agreement with a weak shortwave exiting the area
Monday morning and a weak ridge moving in Monday into Monday
evening. An elongated surface high will sit to our north as well
through the day keeping the area dry. This ridge quickly will exit
off to the east/southeast as a trough sets up to our west, with the
axis from Alberta/Saskatchewan southwestward into Idaho by 12Z
Tuesday. A surface low will be positioned just ahead of this trough
with the stationary, turning warm front, draped across the CWA from
northwest to southeast. This wave and surface low pushes east
through the day Tuesday into Tuesday evening with the cold front
part of the system forecasted to push eastward over the CWA early
Wednesday. The shortwave will then exit our area towards the end of
the week with ensembles differing on timing and intensity as it does
so. Another surface low will swing down from the northwest during
this time, associated with its incoming weak wave.

Precipitation wise, ensembles indicate rain moving in from the
west/northwest (minor timing differences between the models) early
Tuesday morning and overspreading the CWA by Tuesday afternoon and
rain shower chances continuing into the night. NBM indicates our
highest pops (35-65%) will be mainly Tuesday afternoon and evening
for now. Rain chances continue into Wednesday (20-45%) before
diminishing west to east Wednesday evening. Probability of QPF>
0.25" for this time ranges from 40-75% with GEFS being the most
aggressive in the highest QPF. Prob of 0.50" ranges from 10-20% EC
and 10-45% GEFS. GEFS prob of CAPE>500 j/kg and shear>30kts remains
low for any organized severe at 5-10% across south central SD, but
there should be enough energy for general thunder Tuesday afternoon
and evening in the warm sector of the low from north central to
south central SD. Additional pops (15-30%) are noted with NBM with
the following system for Friday, but low confidence on this.

Temperatures Monday and Tuesday will range in the upper 60s into the
lower to mid 70s. Little cooler on Wednesday behind the cold front,
back into the mid to upper 60s/lower 70s. Temps rebound a bit for
the end of the week, back into the 70s.

&&

.AVIATION /06Z TAFS THROUGH 06Z SUNDAY/...
Issued at 1228 AM CDT Sun May 12 2024

Terminals KABR,KATY,KPIR,KMBG

VFR conditions will prevail across the area through the TAF period.
West winds will shift to the north today, then to the northeast
tonight.

&&

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

$$

UPDATE...Dorn
SHORT TERM...Connelly
LONG TERM...MMM
AVIATION...Parkin