048
FXUS63 KFSD 070827
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
327 AM CDT Fri Jun 7 2024

.KEY MESSAGES...

- Scattered showers and isolated thunderstorms return to the
  area today into tonight. There is a low probability of a
  strong to severe storm along the Missouri River during the
  afternoon/evening.

- Slightly cooler temperatures with relatively light winds for
  the upcoming weekend.

- Low confidence in precipitation chances for Sunday into the
  beginning of next week with significant model differences.

- Chances for above normal temperatures return late next week
  as a ridge of high pressure builds across the south.

&&

.DISCUSSION...
Issued at 325 AM CDT Fri Jun 7 2024

Clear skies across the region early this morning with weak surface
high pressure situated over our area. The surface ridge will shift
eastward into the central Mississippi Valley during the day, this as
a surface low deepens over western NE and KS. In response, calm
winds this morning will increase a bit by afternoon - out of the
south as the high moves to the east and the surface pressure
gradient tightens up slightly. Even so, winds will be much lighter
than the past couple of days with much lighter winds at the top of
the mixed layer. Otherwise, an upper level shortwave slides eastward
across southern SD during the day. With that, scattered showers and
isolated thunderstorms are expected to develop across the area as
midlevel warm air advection overspreads the region. Although SPC has
outlined portions of the MO River Valley in a Marginal convective
risk, think that the potential for severe storms is low. While there
will be plenty of effective bulk shear (50 kts+) in place across the
region this afternoon and evening, almost all models (with the
exception of the NAM) indicate the more significant instability
(1000 J/KG +) remaining well to the south and west of our CWA. If
the NAM were to verify - with CAPE of around 1000 J/KG through south
central SD, then the potential for a stronger to severe storm would
be greater over that area. As for precipitation amounts for today,
they would be on the lighter side (a tenth of an inch or less) with
model soundings indicating a layer of dry air below 700 mb. As for
temperatures today, they will remain seasonable in the mid to upper
70s.

While any showers and storms will most likely diminish by late
evening, there could be additional light showers over the eastern
portions of our CWA later tonight as another upper level impulse
drifts across the region. Lows tonight will drop into the 50s once
again.

Surface high pressure slowly builds across the region for the
upcoming weekend. This will bring slightly cooler temperatures with
highs generally in the low to mid 70s. Northerly winds will be
relatively light on Saturday, with a touch more of a breeze on
Sunday - though not out of the ordinary with sustained winds of 10
to 15 mph. Most models would indicate a dry weekend ahead - with the
exception being the GFS which becomes a significant outlier as we
move into the beginning of next week. While the ECMWF/Canadian/and
NAM all begin to build an upper level ridge over the region by
Sunday, the GFS wants to drop an upper level low into the Northern
Plains on Sunday and Monday. If that were to occur, then rain
chances would increase on Sunday into Monday. At this point, will
ignore that solution since it is an outlier from the rest of the
models. These same trends are displayed in the respective 00Z
ensembles.

For Tuesday through Thursday, while the GFS continues to be an
outlier early in the period, our next chance of precipitation could
come on Tuesday as both the ECMWF and Canadian bring an upper level
trough into the region. By mid and late week, models (and ensembles)
trend to toward a broad upper level ridge building over the central
CONUS. This is reflected in warming temperatures as highs climb into
the 80s to near 90 during this period - which is supported by both
NAEFS and ECMWF ensembles which indicate 700/850 mb temperatures
into the 90th percentile with respect to climatology by the end of
the week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1038 PM CDT Thu Jun 6 2024

VFR conditions are expected for the TAF period. Light winds begin
the TAF period and will remain light and variable through the
overnight hours. Winds turn southeasterly tomorrow morning with
speeds up to 5-15 knots with gusts up to 15 to 20 knots. Light
showers will move into the area by the late morning hours but dry
air in the low levels may prevent rain from reaching the surface. As
such, have kept any chance for rain limited to VCSH. Have also left
out any mention of thunder as any storms that develop during the
afternoon hours look to be mainly south of the Missouri River.
Trends will be monitored through the night. Dry conditions will
finish out the TAF period.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...None.
MN...None.
IA...None.
NE...None.

&&

$$

DISCUSSION...JM
AVIATION...Meyers