320
FXUS63 KFSD 091117
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
617 AM CDT Thu May 9 2024

.KEY MESSAGES...

- Widespread showers push south across the area. Additional
  isolated showers and storms are possible this afternoon into
  this evening, but confidence in coverage is low.

- Warmer and mainly dry conditions Friday into Sunday. Continued
  warm with renewed rain chances by early next week. Best
  chances currently expected mid week.

&&

.DISCUSSION...
Issued at 322 AM CDT Thu May 9 2024

CURRENTS THROUGH TONIGHT: Showers continue to pivot from northeast
to southwest over the area this morning. Rainfall amounts since
midnight have been less than 0.10" with a few sites in northwestern
IA over 0.25". Additional rainfall amounts through the rest of today
and into tonight should be less than 0.25". Cloud cover and rain are
keeping temperatures in the upper 40s to mid 50s, and we`ll fall
into the 40s by daybreak.

We`ll continue to see the mid/upper level low flatten and shear out
as it slides south through today. This will drag the bulk of the
rain and isolated storm chances toward the Hwy 20 corridor by the
late morning/early afternoon. However, expect some additional and
isolated showers/storms to pop up over the forecast area. Soundings
indicate some weak elevated instability (at or less than 200 J/kg)
at the top of the mixed layer, which will serve as the catalyst for
this development. May see more virga than bonafide showers or
sprinkles with a fairly robust dry sub cloud layer and thus limited
coverage of pops. A mix of clouds and sun is anticipated with highs
in the 60s to lower 70s. Breezy north to northeast winds today may
gust around 25 mph. Isolated gusts are possible with showers and
storms.

Another wave grazes the eastern portions of the forecast area late
this evening through tonight but without much moisture to work with,
expect dry weather overnight. Lows fall into the 40s.

TOMORROW THROUGH THE WEEKEND: Mostly dry but somewhat unsettled
weather through the weekend. A mid level trough dives across MN
Friday afternoon and evening, which may bring some isolated showers
and possibly a rumble of thunder or two to areas along and east of
Hwy 75. Elevated instability is less (around 100 J/kg), and dry sub
cloud layer may once again limit precipitation. Temperatures Friday
warm into the upper 60s and lower 70s although breezy northwesterly
winds will probably make it feel a touch cooler. Sustained winds
Friday will be around 15-25 mph and gusts to 35 mph. Warmer on
Saturday, with more low level westerly flow and WAA. Highs in the
70s, with some folks along/west of the James River possibly
approaching the 80 degree mark. A low pressure system is expected to
move across the south central Plains late Saturday into Sunday which
may bring some isolated rain/storm chances to the area as the wave
lifts north. Confidence is a bit low in the coverage of these rain
chances, given how varied the track of the low is by Sunday evening
(09.00z models show the center of the mid level low anywhere from
north central NE to western KS/eastern CO. Highs on Sunday again in
the upper 70s to lower 80s. Lows through the weekend in the 40s and
50s.

EARLY TO MID NEXT WEEK: Aforementioned low pressure continues to
move across portions of the Plains into early next week, with models
showing another wave progged to move through mid week. This keeps
periodic rain and storm chances in the forecast, but with the
timing/track differences of each of these lows, confidence is too
low to narrow pops more from the NBM. Best chances do look to be
with the stronger wave/trough axis mid week. Precipitation chances
may be more diurnally driven given the timing of the waves and
increasing afternoon instability. Temperatures remain near to above
normal - warmest early in the week. Highs in the 70s to lower 80s
continue, with lows mainly in the 50s. Periodic breezy conditions
expected.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 612 AM CDT Thu May 9 2024

VFR conditions prevail today, although some isolated MVFR
conditions may occur with showers/rain through the day. Areas of
showers continue to move southwest this morning across
southeastern SD into north central IA and will do so through the
early afternoon hours. Although confidence is low in occurrence,
an isolated lightning strike or two is possible south of I-90.
Additional isolated showers and storms are possible again this
afternoon and this evening across the forecast area. Included a
VCSH mention at KHON, with guidance consistently developing
showers west of the James River. Otherwise, coverage remains too
isolated to include at KFSD or KSUX. Any lingering showers
should taper off through late evening.

Winds out of the north/northwest increase today, with gusts to
20 knots possible. Light and variable winds late in the period
become westerly by Friday morning.

&&

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

&&

$$

DISCUSSION...SG
AVIATION...SG