478
FXUS63 KFSD 142259
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
559 PM CDT Tue May 14 2024

.KEY MESSAGES...

- Scattered showers and thunderstorms will be possible tonight but
the severe weather threat is very low.

- Additional showers and thunderstorms are likely Wednesday
afternoon and night with a low chance for severe thunderstorms.

- Well above normal temperatures are expected Friday and Saturday.

- A more active southern stream jet is expected next week which
  could bring a better chance for increased shower and
  thunderstorm coverage.

&&

.DISCUSSION...
Issued at 302 PM CDT Tue May 14 2024

The latest water vapor imagery indicates a small shortwave moving
into western SD/NE early this afternoon. Some drier potentially more
unstable air was moving into NE just ahead of this wave and could
aid in thunderstorm development across northern NE and southern SD
later this afternoon and evening. The environment ahead of this wave
is not very impressive and will likely not support any severe
weather. A dry sub cloud layer could support some gusty winds. This
activity will linger through the night and move eastward. The
overall impacts from this wave will be minimal. Lows in the 50s are
expected.

A second wave will move into the area on Wednesday and bring another
chance for showers and thunderstorms. While mid morning into early
afternoon will see the least amount of coverage, the combination of
peak heating and this wave should allow for scattered thunderstorms
to develop east of the James River on Wednesday afternoon. While
very isolated severe storms will be possible the combination of
marginal shear and instability will not support much in the way of
stronger updrafts. Locally heavy downpours are likely but a more
widespread heavy rain event is not expected. This wave will move
through the areas during the evening and shift most of the forcing
and instability east of the area shortly after midnight. Highs
Wednesday should be in the 70s with lows that night from the upper
40s to lower 50s.

Thursday will be mainly dry and mild with highs in the 70s. A weak
trailing wave will move through during the afternoon with little
moisture to work with. This will bring a chance for isolated showers
and thunderstorms but impacts should be minor.

Friday into Saturday will see an upper level ridge move east as a
wave moves along the Canadian border. This will swing a trough of
low pressure through the area and bring small chances for showers
and thunderstorms. Currently instability and shear look marginal at
best with a little too much dry air around, so severe weather is
pretty unlikely. Both days will be warm with lows in the 50s and
highs 75 to 85.

A more active southern stream upper level jet is expected Monday into
Wednesday next week and should bring better chances for showers and
thunderstorms. Not necessarily severe weather, but an increase in
coverage. Given the expected pattern not a whole lot of change in
temperatures with highs in the 70s and lows in the 50s.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 549 PM CDT Tue May 14 2024

Scattered showers and thunderstorms over western and central SD
will push to the east through the evening and overnight
hours. With the onset of shower/thunderstorm activity, ceilings
will lower into the MVFR/IFR range. While showers will wane by
Wednesday morning, additional showers and thunderstorms are
expected to develop on Wednesday afternoon as a frontal boundary
moves across the area. With the passage of this boundary,
southeasterly winds will transition to northwesterly west of
Interstate 29 through the afternoon.

&&

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

&&

$$

DISCUSSION...08
AVIATION...08