059
FXUS63 KABR 060524
AFDABR

Area Forecast Discussion
National Weather Service Aberdeen SD
1224 AM CDT Sat Jul 6 2024

.KEY MESSAGES...

- Scattered showers and thunderstorms are expected to track from
  west to east across the region from Saturday morning to Saturday
  evening. The severe threat is generally low, although a stronger
  storm or two is possible along and south of US Highway 14.

- Isolated shower and thunderstorm chances remain in the forecast
  on both Sunday and Monday. However, a pattern change seems
  likely thereafter. Expect a gradual warming trend through the
  work week. By the end of the week we should be seeing
  temperatures 5 to 10 degrees above average (highs in the upper
  80s-90s).

&&

.UPDATE...
Issued at 907 PM CDT Fri Jul 5 2024

Still just a few showers and weak thunderstorms around this
evening, mainly across parts of central South Dakota. These will
likely dissipate before 10pm with the loss of daytime heating. The
next area of precipitation that is expected to affect the CWA
overnight is now over western North Dakota and far northwestern
South Dakota. No changes made to winds or temperatures at this
time.

&&

.SHORT TERM /THIS EVENING THROUGH SATURDAY NIGHT/...
Issued at 207 PM CDT Fri Jul 5 2024

Plenty of sunshine, instability (1000-2000 J/KG CAPE) and steep low
level lapse rates have resulted in isolated showers and
thunderstorms across the region. These should be short lived and
will diminish along with the setting sun. The rest of the evening
should be dry with lows dropping into the mid 50s/low 60s.

Another shortwave will work across the region Saturday. While decent
upper level forcing, the low level pressure pattern remains weak.
Instability will be limited. Bulk shear does increase across
southern South Dakota, with progs around 30kts for areas along and
south of Highway 14. This may be enough for a stronger storm or two
and the region is in a marginal (1 of 5) risk for severe weather.
Showers and thunderstorms may linger into the evening and overnight
hours.

High confidence in the temperatures forecast. Ensemble Max/Min T
spread is generally 5 degrees or less. Expect temperatures to
continue to be near or slightly below normal through the weekend.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 207 PM CDT Fri Jul 5 2024

Not too much of a change for the long term as Clusters continue to
indicate a highly amplified ridge over the western Conus/Pacific and
a trough over the Southern Plains through the Upper Midwest Sunday
into Monday. This pattern continues to bring in several embedded
shortwaves over the Northern Plains. We finally start to see a shift
eastward in the trough and ridge Tuesday. By Wednesday, Clusters
"overall agree" on the axis of the ridge over central Canada through
the intermountain West (and western Conus). However, Clusters 1 and
3 (made up of mostly EC) keeps the axis slightly further westward
than the other ensembles. By the end of the week, the ridge becomes
more broad with much of the Conus underneath it into next weekend.
There is slight timing and intensity differences of the ridge this
far out between the ensembles.

At the surface a low is forecasted to be centered over ND/SD/MN
border early Sunday morning, along the 850mb trough. Most of the CWA
will be post frontal at this point besides eastern SD into west
central MN. Through the day this low and front will continue
east/northeastward as a high pressure system will move in behind it.
Chance of light precip is possible Sunday morning-midday (15-30%)
before chances increase with diurnal heating to 30-45% across the
CWA with this system. Just enough afternoon instability (up to ~1000
j/kg CAPE or so per GEFS) should be present for general
thunderstorms with severe threat on the low side as shear remains
weak. Any storms should dissipate by sunset. High pressure system
over much of central and western SD for Monday with the possibility
of isolated (15-25%) afternoon showers and thunderstorms, mainly
over eastern SD/western MN (behind the exiting low) and help from
the embedded wave. Again just enough CAPE for general thunder as
shear remains low. Another wave and surface trough look possible
Tuesday, however, forecast remains dry for now. Otherwise into the
midweek, the forecast looks quiet and dry.

With the incoming ridge, temps will gradually warm up from west to
east across the CWA next week, with temps back into the 80s Tuesday
and Wednesday. Probability of 90 degrees and above Thursday is 25-
50% from north central to south central SD. For Friday, prob
increases to 30-85% over this same area. NBM 25th-75th spread is not
too bad ranging from 3-6 degrees next week. So depends on the speed
eastward of the ridge and intensity, as mentioned earlier.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1223 AM CDT Sat Jul 6 2024

Terminals KABR,KATY,KPIR,KMBG

Showers and thunderstorms will track across the area overnight into
early Saturday morning. Additional shower and thunderstorm
development is expected across the area Saturday afternoon and
evening. For the most part, VFR conditions will prevail overnight
and through the day Saturday, but there may be brief periods of MVFR
vsbys with any thunderstorms that develop.

&&

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

$$

UPDATE...Parkin
SHORT TERM...Serr
LONG TERM...MMM
AVIATION...Parkin