324
FXUS63 KFSD 281943
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
243 PM CDT Tue May 28 2024

.KEY MESSAGES...

- Dry on Wednesday. Multiple chances for showers and
  thunderstorms starting late Wednesday night and continuing
  into next week. A few storms may become strong to severe over
  the weekend.

- Near normal temperatures prevail with periodic breezy
  conditions into early next week.

&&

.DISCUSSION...
Issued at 242 PM CDT Tue May 28 2024

CURRENT THROUGH WEDNESDAY: Quiet conditions continue across the
region in the wake of this morning`s showers, with latest
observations showing partly cloudy skies, breezy N/NW winds, and
temperatures in the 60s. Should see gusts quickly diminish near
sunset, allowing light winds, clear skies, and lows in the 40s to
prevail overnight as sfc high pressure slides overhead.

Upper level ridging builds across the Northern Plains Wednesday,
keeping conditions dry across our area. As alluded to in the
previous discussion, will see S/SE winds gradually increase
throughout the day along and west of the James River thanks to a
tightening SPG. Thus, expect gusts to range between 25 to 35 MPH by
sunset, with areas east of the James River ranging between 15 to 25
MPH. Highs during this time look to remain seasonal, with
temperatures forecast to rise into the low to mid 70s.

WEDNESDAY NIGHT THROUGH FRIDAY: Chances for showers and storms
return late Wednesday night as an upper level trough over the
western CONUS ejects northeastward toward the region. Will likely
see precipitation begin near midnight as broad WAA overspreads our
area, with the better chances (>50%) focused during the daylight
hours Thursday. Overall instability and shear look rather meager,
suggesting that the threat from severe weather should remain low.
That being said, can`t rule out the possibility of seeing localized
heavy rainfall and a few rumbles of thunder. Southerly winds will
also be fairly breezy during this time, with gusts between 20 to 30
MPH.

Trough axis swings north of the area on Friday, with another weak
short wave ahead of it, although this wave may stay largely to our
south. This keeps at least scattered activity around through the end
of the week. Areas across south central SD through Friday have high
probabilities (> 60%) of seeing greater than or equal to half an
inch of rain, with low to moderate probabilities (< 40%) of seeing
an inch of rain in a 24 hour period. As noted in the previous
discussion, will need to keep an eye on trends, but generally think
flash flooding risk is low given 1 hour flash flood guidance
near/above 2 inches in most of this area. In regard to temperatures,
look for highs to remain in the 70s, with lows generally in the 50s.

SATURDAY THROUGH TUESDAY: Another shortwave takes aim at the region
Saturday afternoon through Sunday, bringing with it chances for a
few strong to severe storms. Model consistency still remains rather
poor to put too much confidence behind any one solution just yet.
Nonetheless, most agree that coverage would be more
isolated/scattered Saturday evening, with more widespread coverage
expected Sunday night into early Monday morning as a front pushes
eastward across the region. Do think it`s worth noting that both
CIPS and CSU Machine Learning both suggest a 10-15% chance of seeing
severe weather across our area. Latest EC/GFS ensembles also show
high probabilities (>70%) of our area seeing CAPE exceed 1000 J/kg,
with moderate probabilities (30-60%) CAPE exceeding 2000 J/kg. In
addition to this, latest guidance shows steep mid level lapse rates
(>7 degC/km) and PWATs greater than an inch. Again, with models
varying in the details, there remains quite a lot of uncertainty,
but folks without outdoor and/or travel plans should keep an eye on
the forecast for the weekend. Otherwise, look precipitation chances
to continue heading into the new week, with highs rising into the
80s.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1127 AM CDT Tue May 28 2024

VFR conditions expected through the period. Afternoon Cu will
continue to bubble near and east of the James River through
late afternoon/early evening but should stay in the VFR
category. Northerly winds will occasionally gust between 15-25
kts this afternoon, decreasing after sunset.

&&

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

&&

$$

DISCUSSION...SST
AVIATION...Kalin