Box Elder, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

621
FXUS63 KUNR 091047
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
447 AM MDT Mon Jun 9 2025

.KEY MESSAGES...

- Unseasonably warm temperatures through the mid week with highs
  potentially reaching the upper 80s to low 90s (5-10F above
  average) on Tuesday.

- Thunderstorms are possible Tuesday evening/night, severe weather
  not anticipated at this time.

- Active weather for the latter half of the week with daily
  chances for showers and storms.

&&

.DISCUSSION...(Today Through Sunday)
Issued at 244 AM MDT Mon Jun 9 2025

Current WV and IR satellite imagery shows upper low centered over
northern MN/WI. Canadian wildfire smoke is being pulled into the
region as northwest flow sets up over the region ahead of a
building western US ridge. Sfc obs indicate this smoke is mostly
aloft, though a few AQ monitoring stations around the region have
noted degraded air quality. HRRR and RAP near sfc and vertically
integrated smoke models show smoke returning to the region today.
Have opted to put haze in the wx grids as not entirely confident
in smoke mixing to the sfc.

Upper level ridge will build into the region today as the upper
low shifts to the east. This will support warming temperatures and
dry weather for today into tomorrow. H850 temps will warm to
around 25C by tomorrow afternoon as low level south-southwesterly
flow facilitates development of low level thermal ridge over the
region. Temperatures tomorrow afternoon will reach into the 80s
across much of the CWA. Downsloping could support temperatures in
the low to mid 90s over the western SD plains east of the Black
Hills (70-90+% probs per HREF).

With the hot temperatures and increasing mid-level moisture
associated with an approaching lead shortwave, could see
convection over the Black Hills into northeastern WY late Tuesday
afternoon. Therefore have opted to paint slgt chc PoPs for Tuesday
afternoon for northeastern WY into the Black Hills. Severe
weather not anticipated, though forecast soundings show a well
mixed and deep boundary layer, which would support strong wind
gusts in any stronger convection that develops Tuesday afternoon.
CAMs depict thunderstorms developing over northeastern WY and the
Black Hills later Tuesday afternoon and pushing eastward through
the evening hours.

Quasi-zonal flow re-establishes itself over the region Wednesday
as the shortwave pushes east. Temperatures should moderate with
highs dropping into the upper 70s to 80s by Wednesday. Another
shortwave progged to impact the region late Wednesday into
Thursday, bringing more chances for storms Wednesday night. Upper
ridge builds into the region by the weekend with unsettled
southwest flow developing over the Northern Plains. This points to
warmer temperatures by the weekend and daily chances for storms
as disturbances ripple along the flow.

&&

.AVIATION...(For the 12Z TAFS Through 12Z Tuesday Morning)
Issued At 442 AM MDT Mon Jun 9 2025

VFR conditions expected through the TAF period. Northwest winds
will pick up over western SD this afternoon with gusts of up to 25kt.

&&

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

$$

DISCUSSION/KEY MESSAGES...Wong
AVIATION...Wong