127
FXUS63 KUNR 170434
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1034 PM MDT Tue Jul 16 2024

.KEY MESSAGES...

- Near average temperatures continue, with nearly daily chances
  for isolated to scattered thunderstorms.

- Best chance of more widespread precipitation on Friday

&&

.DISCUSSION...(This Evening Through Tuesday)
Issued at 148 PM MDT Tue Jul 16 2024

Current upper analysis shows a ridge building over the western
CONUS with a southeastward moving upper trough/low over the Great
Lakes region, resulting in northwesterly flow aloft over the
forecast area this afternoon. A surface cool front extends from
northeast to southwest across south central SD with around
1500J/kg to the south of the boundary. A line of convection has
developed along the front in Nebraska and just to the south of the
Neb/SD border. There is still a chance of thunderstorms
developing over parts of south central SD this afternoon, however
the front may push to the southeast of the forecast area before
convection is able to develop there. The best coverage/severe
threat will be to the south of south central SD in Nebraska.
Isolated thunderstorms had earlier developed over and near the
southern Black Hills. May see some redevelopment there during the
rest of the afternoon, however chances decrease quickly this
evening.

Northwest flow aloft continues through the remainder of the week
as a persistent upper level ridge remains over the western CONUS.
A surface high will slip across the eastern Dakotas on
Wednesday/Thursday with mainly conditions for much of the area.
However, a narrow axis of buoyancy will favor some isolated
thunderstorm activity, especially across northeastern
Wyoming/western South Dakota on Wednesday and Thursday. The
chance for thunderstorms continue into the weekend as several
impulses rotate over the ridge and drop through the plains. The
best chances for more widespread rain will be on Friday. Highs
will mainly be in the 80s through the forecast period with 70s in
the Black Hills. Thursday and Friday will be the warmest days with
some locations on the plains reaching into the 90s.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Wednesday Night)
Issued At 1032 PM MDT Tue Jul 16 2024

VFR conditions are expected through the forecast period. An
isolated shower/storm may be possible Wednesday afternoon, mainly
over the Black Hills into southwestern SD. Transient MVFR
conditions can be expected in/near any storms in addition to
gusty, erratic winds.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&

$$

DISCUSSION/KEY MESSAGES...10
AVIATION...Dye