633
FXUS63 KFSD 071523
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
1023 AM CDT Tue May 7 2024

.KEY MESSAGES...

- A Wind Advisory has been issued for Gregory, Jerauld, Brule,
  Aurora, Charles Mix, and Douglas counties for gusts up to 45
  mph. The Advisory is in effect until 7 pm this evening.

- More widespread rain and isolated storm chances on Wednesday.
  Although severe weather is not expected, funnel clouds and
  locally heavy rain are possible - mainly along/east of I-29.

- Warmer and mostly dry conditions move in for the weekend and
  into early next week.

&&

.UPDATE...
Issued at 1021 AM CDT Tue May 7 2024

Westerly winds have already begun to strengthen this
morning along and west of the James River. A few gusts have already
touched 45 mph just west of the Missouri River. With mixing expected
to further strengthen through the rest of the morning hours along
with soundings showing no inversion at the top of the mixed layer,
expect strong wind gusts to persist through the afternoon hours. As
such, have issued a Wind Advisory for Gregory, Jerauld, Brule,
Aurora, Charles Mix, and Douglas counties for gusts up to 45 mph.
The Advisory is in effect through 7 pm this evening. Trends in the
strength of the wind will be monitored throughout the day today
which could result in expansions to the Advisory.

&&

.DISCUSSION...
Issued at 346 AM CDT Tue May 7 2024

CURRENTS: Showers and isolated storms are continuing to move out of
southwestern MN and northwestern IA early this morning. Winds are
already on the increase, with gusts through 3 AM CDT/08z around 20
to 35 mph. Seeing some breaks in the clouds across south central
into northwestern SD, but this is short lived as more cloud cover
pivots around the mid/upper low pressure. Temperatures are
holding steady in the 50s, but do expect areas in west of I-29
to fall into the mid/upper 40s by daybreak.

TODAY AND TONIGHT: Mid and upper level low continues to spin and
meander into western ND. We`ll be in westerly flow for part of the
day, with streams of vorticity advecting over the area. Expect
mostly cloudy skies today with the low off to our northwest.
Vorticity as well as some very weak instability (less than 100 J/kg)
could lead to isolated showers through the day; however, soundings
show that we may struggle a bit with saturation in this unstable
layer, so showers remain isolated and limited mention to sprinkles.
Near average temperatures with highs in the 60s to lower 70s. Winds
remain breezy today (out of the southwest by the afternoon) with
gusts 30 to 40 mph and sustained winds around 10-20 mph thanks to
strong flow aloft and a compressed surface pressure gradient. Could
see some isolated higher gusts in south central SD where mixing may
be more efficient later this afternoon, and stronger gusts may also
mix down with showers. Will keep an eye on the potential for a small
Wind Advisory in south central SD, especially if some of the these
more mixy soundings end up being reality. Winds and showers taper
off after sunset as we lose mixing. Lows tonight fall into the 40s.

WEDNESDAY: Mid and upper low wobbles back to the east Wednesday,
centering itself over our forecast area. This brings back more
widespread shower chances with isolated thunderstorms. Instability
is still fairly weak around 1000 J/kg, although some of the
more aggressive models (like the RAP) do have instability around
1500 J/kg. Severe weather looks unlikely - that said, cannot
entirely rule out some funnels and/or landspouts with showers
and isolated storms with the mid/upper low overhead. Mid level
lapse rates at or above 7 deg C/km coincident with the instability
and vorticity advection are somewhat favorable for this potential
along and east of I-29 during the late morning through the
afternoon hours. Folks should keep an eye on the forecast. Could
also see some brief and localized heavy rainfall with slower
shower/storm motion, with some rainfall totals east of I-29
possibly approaching an inch. Otherwise, less breezy with
north/northeast winds. Widespread showers/isolated storms and
cloud cover keeps temperatures a bit cooler, in the 60s. Lows
fall into the 40s once again.

THURSDAY INTO EARLY NEXT WEEK: Lingering showers into the day on
Thursday as the mid/upper low finally moves off to the south. Near
normal temps expected. A mid level wave and upper jet swing through
eastern ND and MN on Friday, which could bring back showers and
isolated storms to areas east of I-29 into the day Saturday. Ridging
begins to build across the Rockies by the latter half of the weekend,
allowing us to warm to above average temperatures with mostly dry
conditions into the early part of next week as the ridge axis slides
eastward.

&&

.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 622 AM CDT Tue May 7 2024

Watching an area of MVFR/IFR and patchy LIFR stratus lift
northeast out of northwestern IA and southwestern MN this
morning. Models are not handling this area well, but expect it
to lift northeast of US Highway 59 by mid morning. Otherwise,
watching low VFR ceilings advect in from the west, pivoting
around the low pressure. Clouds prevail today with isolated
showers. Have left any mention of precip out of the TAF given
low confidence in coverage and timing.

Otherwise, breezy to strong winds expected through today. Gusts
around 25 to 35 knots, highest across south central SD. Could
see some higher gusts in south central SD and with any showers
that develop. Direction shift to more southwesterly during the
day. Winds drop off after sunset, becoming somewhat variable due
to the pivoting low pressure.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory until 7 PM CDT this evening for SDZ050-052-057-
     058-063-064.
MN...None.
IA...None.
NE...None.

&&

$$

UPDATE...Meyers
DISCUSSION...SG
AVIATION...SG