Area Forecast Discussion
Issued by NWS Sioux Falls, SD

Home |  Current Version |  Previous Version |  Graphics & Text |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42
391
FXUS63 KFSD 221939
AFDFSD

Area Forecast Discussion
National Weather Service Sioux Falls SD
239 PM CDT Mon Jul 22 2024

.KEY MESSAGES...

- Patchy fog will again be possible late tonight into Tuesday
  morning.

- Isolated to scattered showers and thunderstorms likely again
  this afternoon and then late tonight into Tuesday. Severe
  storms are not expected, but some small hail and occasional
  funnels or landspout tornadoes could be possible.

- Thick elevated smoke layer will persist for much of the
  upcoming week but he effects at the surface will be minimal
  with only slight impacts to AQI. Some indications that some
  smoke could translate to the surface Tuesday into Wednesday.

- Warm, humid and breezy Thursday into the weekend with very small
  chances (<20%) for heat advisory criteria.

&&

.DISCUSSION...
Issued at 238 PM CDT Mon Jul 22 2024

A weak wave and marginal instability will continue to bring the
threat for isolated to scattered showers and thunderstorms. The
combination of instability and shear will once again not support any
severe weather, but some locally heavy rain will be possible. A
slightly stronger wave will drop into the area late tonight into
Tuesday morning and could bring better chances Tuesday late morning
into the afternoon mainly east of I-29. Warm and a little humid
through Tuesday with lighter winds.

Areas of smoke aloft will continue to stream into the area into
Tuesday and likely Wednesday. Some chance that a bit of surface
based smoke could begin to show up. Western ND appears to
potentially have a bit with early afternoon visibilities about 6-8
miles. Confidence not real high at this point, but something to
watch.

Wednesday should be mostly dry as return flow sets up with southerly
gusts around 20 mph possible west of I-29. Highs generally in the
80s.

Wednesday night into Friday upper level ridging will build into the
area and bring increased temperatures and winds. Ensemble model 850
mb temperatures suggest an average of about 22 to 26 degrees C which
supports surface temperatures into the 90s, especially Friday. Upper
level ridging breaks down a touch on Saturday which allows warmer
temperatures to spread into the area and should see the best chance
for widespread highs in the 90s.

Saturday night into Sunday models indicating a wave breaking down
the ridge and this will likely be our next better chance for showers
and thunderstorms. More than likely will be enough instability and
shear to support a few strong to severe storms, so will just need to
watch trends to the next few days. Sunday night into Monday not as
much agreement but could see a wave follow the Saturday night wave
and bring continued chances for showers and storms into Monday.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1220 PM CDT Mon Jul 22 2024

Isolated shosers and thunderstorms will be possible today,
tonight and Tuesday morning. The better chances will be near and
east of I-29. While some patchy fog will be possible again late
tonight into Tuesday morning it should be fairly shallow.

&&

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

&&

$$

DISCUSSION...08
AVIATION...08