000
FXUS63 KFSD 170838
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
338 AM CDT Wed Apr 17 2024

.KEY MESSAGES...

- A few lingering light showers will dissipate by mid morning.
  Any additional accumulation will be light.

- Wednesday night into Thursday precipitation chances return,
  this time with the focus along and south of HWY 18. There is
  70-100% probability of 0.1 inches of accumulation, with
  pockets up to 0.5 inches possible for this area and south.

- Gusty northwest winds decrease after noon today. Winds will be
  periodically gusty through early next week.

- Cooler, in the 40s and 50s through Saturday. Then, we warm
  back into the 60s by mid week.

&&

.DISCUSSION...
Issued at 333 AM CDT Wed Apr 17 2024

TODAY: Water vapor imagery shows the strong low pressure that
brought showers and thunderstorms Tuesday spinning over the Tri-
State region this morning. The center of the surface low is located
over eastern Iowa and Minnesota. On the backside, scattered light
showers continue. These showers may produce another tenth or two of
rain, but overall we are not expecting much more out of them. The
showers should cease totally by mid morning. A tightening SPG due to
a mid-level ridge and a strong push of CAA will boost our
northwesterly surface winds this morning, as well as limit highs
into the 50s and 60s. Good mixing will tap into the 40-50 kt LLJ,
resulting in gusts of 30-40 mph. Winds taper off after noon as the
low continues to move off to the east. Clouds thin through the day
and will give us peaks at the sun this afternoon before the next
round of showers begins tonight.

TONIGHT: An upper short wave and associated surface cold front moves
through bringing more rain to area, with the focus of heavier rain
along and south of HWY 18. An 850-700 mb deformation zone sets up
just south of the South Dakota/Nebraska border in the late hours of
Wednesday night. Here, 850-700 mb frontogenesis will serve as the
focal point for shower formation. There is a small elevated mixed
layer providing very weak instability. So, the most likely scenario
is these remain garden variety rain showers with a few rumbles of
thunder possible. Ensembles indicate 70-100% probability the
aforementioned area will see at least a tenth of an inch, with a 30-
70% probability of at least a half inch. This matches well with WPC
QPF guidance. Chances for precipitation drop off quickly as you head
north of I-90.

THURSDAY-SATURDAY: Showers clear out by Thursday late morning.
Thursday afternoon through Saturday, surface high pressure will be
present with mostly zonal flow aloft. Winds will be primarily
northwesterly and periodically gusty. This pattern brings
several pushes of CAA with it, keeping our temperatures cooler
than average by about ten degrees, in the upper 40s to low 50s.
Overnight temperatures during this period will drop below
freezing, into the upper 20s. So, if you had spring fever and
already bought plants for your gardens, be sure to either bring
them inside or cover them so they won`t get frost nipped.

SUNDAY AND BEYOND: Sunday brings a change in wind directions as a
surface high pressure moves through to the southeast. Winds will
become southerly, bringing warmer air with it. Highs will begin to
climb back to normal for Sunday afternoon, in the upper 50s to low
60s. This warming trend will continue through the middle of next
week. Our next shot at precipitation will be Monday night as a low
pressure system over Saskatchewan drags a couple fronts through the
area. Model guidance agreement is low at this time, and so we
encourage you to check back for updates.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1035 PM CDT Tue Apr 16 2024

Current satellite shows abundant cloud cover across the area as a
low pressure system continues to slowly push off to the northeast.
Scattered light showers persist across the area and will continue
through most of the night before pushing off to the northeast along
with the low pressure system. Ceilings remain a mix of VFR/MVFR/IFR
levels but will be lowering to MVFR/IFR thresholds through the
night. Northwest winds are expected to strengthen on the backside of
the departing low with gusts up to around 25-35 knots, strongest
along the Missouri River Valley.

MVFR/IFR ceilings will persist through the morning hours before
breaking up for the afternoon hours. Winds will remain gusty will be
waning throughout the day.

The next chance for rain will come at the end of the TAF period
along and south of I-90. Have included light SHRA in KFSD`s and
KSUX`s TAF. Some shifts in the track of the rain are possible but
confidence is moderate to high (50-80% chance) that rain will fall
in this area. Ceilings look to begin to fall back to MVFR levels to
end the TAF period.

&&

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

&&

$$

DISCUSSION...AJP
AVIATION...Meyers