000
FXUS63 KFSD 180826
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
326 AM CDT Thu Apr 18 2024

.KEY MESSAGES...

- A line of light rain showers southeast of a line from Tyndall-
  Sioux Center-Worthington is ongoing this morning. Expect these
  showers to move out of the area by mid morning. Additional
  accumulation is a couple hundredths to a quarter inch near Ida
  Grove and Storm Lake Iowa.

- Temperatures Today through Saturday are expected to be about
  10 degrees below average for this time of year, in the 40s and
  50s. Overnight lows through Saturday are expected to be at to
  5 degrees below freezing. Have a plan for your cold sensitive
  outdoor plants.

- Moderate chances (40-60%) for rain Monday, but many questions
  on location and amounts remain.

&&

.DISCUSSION...
Issued at 315 AM CDT Thu Apr 18 2024

TODAY (Thursday): Light showers continue to move east-northeast
across southeastern South Dakota, northeastern Nebraska,
northwestern Iowa, and southwestern Minnesota this morning.
Southeast of a line from Tyndall-Sioux Center-Worthington is
where the highest totals are expected. Expect these showers to
move out of the area by mid morning. Winds are northwesterly and
will become gusty by late morning due to a strong push of CAA
and the SPG tightening as a surface high pressure builds in. At
their peak this afternoon they will be sustained at 15-25 mph
with gusts 30-35 mph. Temperatures at 850 mb will cool down to
zero to minus 2 Celsius. Translated to the surface, highs will
only reach the upper 40s and 50s this afternoon. Clouds will
clear from the northwest to the northeast, eventually revealing
mostly sunny skies. Overnight lows dip into the low 30s. In
fact, lows will be at to 5 degrees below freezing through Sunday
night. If you have cold sensitive outdoor plants, it may be a
good idea to have covers ready for them.

FRIDAY-SATURDAY: Aloft, flow remains mostly zonal Friday through
Saturday. Several pushes of CAA at 850 mb cool temperatures into the
minus 2 to minus 8 C range. At the surface, diurnally gusty winds
will vary a little bit from northwesterly to westerly and back
again. The combination of the two will result in highs around 10
degrees cooler than average for this time of year, mid 40s to low
50s both days.

SUNDAY AND BEYOND: By Sunday, an upper ridge begins to build into
the area. Winds will become southwesterly to southerly and WAA will
begin to warm things back up. This pattern generally indicates good
mixing, and with 850 mb temps warming to 4 to 10 deg C, at the
surface we can expect to see more seasonable temperatures, in the
upper 50s to low 60s. On Monday, a low pressure centered over
Saskatchewan/Montana/North Dakota will begin to occlude and drag a
warm front through the area. Frontogenesis at 700 mb while we`re in
the warm sector will help to focus some rain shower development. Mid
level lapse rates are lacking, and elevated instability is low, but
may be enough to generate a lightning strike or two. Long term
guidance is coming into better agreement on this storm, however
there is still a lot of time between now and then, and too many
unknowns to speculate on precipitation amounts or locations at
this time. Thanks to continued WAA, highs for Monday will reach
the mid to upper 60s.

On the heels of the warm front will be a cold front that turns winds
northwesterly again. Tuesday`s highs will be cooler thanks to the
resulting CAA, in the mid 50s to low 60s. Another high pressure
ridge builds in for Wednesday, and highs will warm into the mid 60s
for the remainder of the week.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1040 PM CDT Wed Apr 17 2024

Rain showers will continue to overspread the area during the
night, with lowering visibility and ceilings (MVFR) at KSUX.
Showers will move eastward by late tonight into Thursday
morning, with improving visibility and ceilings. Northwesterly
winds will increase on Thursday morning, gusting around 25kts
through the afternoon. Winds will then taper downward by late
Thursday evening.

&&

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

&&

$$

DISCUSSION...AJP
AVIATION...JM