765
FXUS63 KFSD 051952
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
252 PM CDT Sun May 5 2024

.KEY MESSAGES...

- A Wind Advisory has been issued for most of our area Monday,
  excluding northwest Iowa. Additional expansion may still be
  needed.

- A few strong to severe storms will be possible Monday
  afternoon and evening, with the greatest severe threat
  currently focused along and south of the Missouri River and
  Highway 18 corridor.

- Periodic rain chances continue for much of the upcoming week,
  with highs in the 60s to lower 70s. &&

.DISCUSSION...
Issued at 251 PM CDT Sun May 5 2024

CURRENT/TONIGHT: Quiet conditions continue to prevail across the
region, with latest observations showing sunny skies and
temperatures in the 60s. S/SE winds have picked up a bit during this
time, with gusts between 20 to 30 mph being noted thanks to a
deepening sfc trough over eastern MT/WY. As alluded to in the
previous discussion, will see this sfc trough continue to deepen and
shift eastward as an upper level low near the Rockies ejects
northeastward towards the Northern Plains. This will result
increasing cloud cover and continued breezy winds for much of our
area during the overnight period. Given the tightening SPG in place,
have gusts ranging between 20 to 40 MPH by daybreak Monday. Lastly,
with broad WAA overhead, should see lows remain on the milder side
as temperatures only fall into the upper 40s to lower 50s.

MONDAY: Expect the aforementioned upper level low to edge closer to
the western Dakotas Monday morning as a sfc warm front simultaneously
lifts northeastward across our area. As noted in days past, will see
a fairly robust S/SE LLJ develop overhead, which coupled with a
tightening SPG will result in windy conditions through the
afternoon. Currently have gusts ranging between 30 to 50 MPH, thus,
after collaboration with neighbors have issued a Wind Advisory for
most of our area, excluding northwest Iowa. Additional expansion may
still be needed, so continue to monitor the forecast for the latest
updates. With the aid of WAA, should see afternoon highs rise into
the upper 60s to lower 70s, with dewpoints largely in the 50s.

In terms of precipitation, could see some light showers begin
near/shortly after daybreak west of the James River. Precipitation
should become more widespread through the late morning and afternoon
ahead of an advancing cold front. Latest SPC Day 2 Outlook still
maintains a Slight Risk (Level 2 of 5) across the lower MO River
Valley/northeast Nebraska/and parts of northwest Iowa, with a
Marginal Risk (Level 1 of 5) encompassing those areas north up to
the I-90 corridor. Regarding dynamics, most guidance still shows
CAPE values around 500-1000 J/kg in addition to ample bulk shear
(40+ kts). That being said, ensembles continue with low
probabilities of CAPE greater than 1000 J/KG - at only 10-20% over
our area. Soundings have also have maintained their tall and skinny
profile - so think the primary threats with any storm that does
become strong to severe will be damaging gusts up to 70 MPH and
heavy rainfall, with hail to the size of half dollars being a
secondary threat. Confidence remains high that this event will
produce yet another round of meaningful rainfall for most of our
area, as PWATs exceed an inch. In terms of accumulations, the
current forecast has QPF ranging between a quarter of an inch to an
inch, with the highest amounts generally along and east of I-29.
Thus, given the recent rains and saturated soils in place, can`t
rule out the possibility of seeing isolated to scattered flash
flooding occur in urban and low lying areas. Ponding would be
expected in areas elsewhere.

So, in summary - Monday poses the risk of seeing a few strong to
severe storms, with the greatest threat currently focused along and
south of the MO River Valley and Highway 18 corridor. As with any
event, we strongly encourage you to have a way to receive warnings.
Otherwise, expect showers and storms to continue eastward overnight,
allowing largely quiet conditions to return by daybreak Tuesday.

TUESDAY THROUGH FRIDAY: Upper level low continues to spin and wobble
over the Northern Plains through late-week, resulting in persistent
PoPs (20-50%) through Friday. Winds also look to remain fairly
breezy during this period, with gusts as high as 25 to 35 MPH
possible each afternoon. In regard to temperatures, look for highs
to rise into the 60s and lows to fall into the 40s.

SATURDAY THROUGH SUNDAY: Dry conditions are forecast to largely
prevail over the weekend as the aforementioned upper level low
pushes eastward, causing northwesterly flow to set up overhead.
Afternoon highs in the 60s to lower 70s will become common during
this time, with lows remaining in the 40s.

&&

.AVIATION /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1238 PM CDT Sun May 5 2024

VFR conditions are expected to largely prevail this TAF cycle.
Latest satellite imagery shows mostly sunny skies with a bit of cu
starting to develop across across NW Iowa. Should see cu become more
widespread this afternoon with the aid of diurnal heating. In regard
to winds, look for S/SE to continue this afternoon, with gusts
between 20 to 25 MPH possible in areas along and west of I-29.
Otherwise, look for stratus to gradually build in from the west
overnight and breezy winds to become more widespread, with gusts
between 30 to 50 MPH possible after daybreak. Showers and storms
will be possible for much of the day Monday, resulting in periods of
reduced cigs and vsbys.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory from 10 AM to 7 PM CDT Monday for SDZ039-040-
     054>056-060>062-065>071.
     Wind Advisory from 7 AM to 7 PM CDT Monday for SDZ038-050-052-
     053-057>059-063-064.
MN...Wind Advisory from 11 AM to 7 PM CDT Monday for MNZ071-072-080-
     081-089-090-097-098.
IA...None.
NE...Wind Advisory from 10 AM to 7 PM CDT Monday for NEZ013-014.

&&

$$

DISCUSSION...SST
AVIATION...SST