Box Elder, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

587
FXUS63 KUNR 081916
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
116 PM MDT Sun Jun 8 2025

.KEY MESSAGES...

- Gusty NW winds will diminish this evening, but remain breezy on
  the SD plains for Monday

- An overall warming trend is on tap for the week

- Upper flow pattern by mid-week supports more active weather
  across the region beginning Tuesday evening/night

&&

.DISCUSSION...(This Evening Through Sunday)
Issued at 109 PM MDT Sun Jun 8 2025

Current water vapor imagery shows 500hpa low spinning across sern
AB. Minor 850-700hpa frontogenetically induced pcpn band
stretching from NW NE to wrn IA. 500Hpa ridge building across wrn
CONUS.

Upper low will continue to drift SE into the Great Lakes region,
keeping broad cyclonic flow pattern over the region through
Monday. This should allow the areas of smoke to continue to also
drift south out of the region, resulting in clearer skies
overnight and bluer skies for Monday. While not expecting the
windy conditions seen for today(Sunday), do expect NW winds to amp
back up into the breezy (15-25mph) category across the wrn SD
plains during the morning and afternoon hours for Monday. Model
guidance fcst temps overnight & Monday seem reasonable and didnt
stray far from. With winds expected to diminish this evening, will
allow the wind advisory to expire on time at 01Z.

Thoughts then begin to turn toward the Tuesday & Wednesday time
frame when upper flow pattern begins to transition from cyclonic
to more quasi-zonal as wrn CONUS 500hpa ridging moves over the
Rockies. Models are showing indications of first lead 500hpa wave
moving into wrn CWA sometime Tuesday evening with well defined
700hpa theta-e ridge and associated forcing noted. Models are
showing weak sfc trough dropping south into SD during day Tuesday,
becoming E-W oriented in the vcnty of I-90 by 00z Wednesday. 2
meter dwpts begin to pool along this feature during the afternoon
Tuesday, with mid-upper 50s advertised depending upon the model.
GFS & NAM point toward evening/nocturnal convection moving west-
east across the CWA in the 00Z-09Z time frame Wednesday. The NAM
is a bit more bullish with the 850hpa nocturnal jet developing as
well with 30-40kt jet noted pushing into SW-SC SD during that
time. Additionally...noticed that in the 00Z-06Z Wed time frame,
layer Pwats are 100-150% of normal, depending on your model flavor
of choice. MUCAPE values AOA 1000 J/Kg are supportive of
convection. All this goes to say that believe there will be some
sort of complex that develops across our western counties toward
00z Wednesday that traverse east across the CWA through 09-12Z
Wednesday along or just north of boundary.

Things reset as next in series of disturbances traverse in zonal
flow for Wednesday afternoon. Not sure about temperature recovery
as cloud cover during the day will prevent full recovery during
the day. However, 850hpa temps do recover for the remainder of the
week with warming trend anticipated. With SW flow aloft and
disturbances continuing to move through in flow, this typically
spells a more unsettled pattern for the area with
afternoon/evening convection.



&&

.AVIATION...(For the 18Z TAFS Through 18Z Monday)
Issued At 1143 AM MDT Sun Jun 8 2025

Wildfire smoke will continue to affect the region this morning and
afternoon, however no visibility reductions are expected. Northwest
winds with gusts up to 35 to 45kt will diminish over this evening.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Wind Advisory until 7 PM MDT this evening for SDZ001-002-012>014-
     072-073-078.
WY...None.
&&

$$

DISCUSSION/KEY MESSAGES...Hintz
AVIATION...Dye