Box Elder, South Dakota 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

991
FXUS63 KUNR 260519
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1119 PM MDT Sat Jul 25 2026

.KEY MESSAGES...

- Strong high pressure next week will bring very hot temperatures
  and fire weather concerns at times.

- Isolated thunderstorms will be possible nearly each day next
  week. Storms may have gusty winds.

&&

.UPDATE...
Issued at 1008 PM MDT Sat Jul 25 2026

It was a memorable day as both WFO UNR and KRAP broke all-time
record high temperatures. See RERUNR/RERRAP for more details. Latest
surface obs show widespread triple-digit heat has "cooled off" to
the upper 70s to lower 90s. Another warm night is expected tonight.
Some downsloping sections of the eastern foothills may struggle to
reach below 80 through early Sunday morning. KUDX radar shows light
showers across the area. Another upper wave across SE MT may bring
overnight storms overnight, so have added low-end pops. Another
round of storms is expected Sunday afternoon/evening, but CAPE will
be limited given the hot/dry boundary layer. Coverage will be less
than today and organized severe weather is not expected. Still, with
inverted V profiles, can`t rule out some storms having gusty winds.
Temps tomorrow will again be well above the 100F mark...but it`s not
expected to be quite as hot today. With the heat combining with
dewpoints of 55 to 65F tomorrow toward central SD, the Excessive
Heat Warning is still in good shape. I did add Ziebach County to the
warning. Heat Advisory looks good elsewhere. Will need to take a
look at apparent temps on Monday to see if any headlines need to be
extended.

&&

.DISCUSSION...(This Afternoon Through Friday)
Issued at 1106 AM MDT Sat Jul 25 2026

Upper level ridge will remain anchored over the Rockies into the
Plains supporting hot temperatures. Very hot temps the next two
days as the core of the thermal ridge passes over the region.
Expect temps into the 100s on most of the SD Plains and portions
of the WY Plains. Heat products look good most areas, did expand
the extreme heat warning west a couple zones given hotter than
expected temps, with heat index readings of 105 to 110 expected
there. A stronger shortwave filled with monsoon moisture will
advect around the ridge in SW flow and across the FA today,
supporting high based TS. Damaging winds will be possible with
thunderstorms given very high based nature and resultant
inverted-V profiles per drying BL. Sct wind gusts over 60 mph
(possibly over 80 mph in stronger cells) will be possible given
DCAPE over 2000 J/KG, esp on the SD Plains east of the Black
Hills. Not much rain expected with these cells, which will support
critical fire weather conds when coupled with dry fuels,
downburst winds, and low RH. Things will dry out tonight, but it
will remain very warm with lows in the 70s at many areas, with 80s
in the BH foothills. Another hot day Sunday with dry conds most
areas. The exception will be over the BH where diurnal convection
will be possible and with another impulse toward the evening and
overnight. Convection will be possible with this wave mainly in
the western third. Expect gusty winds once again. Ridge will
retrograde back west some by mid next week, supporting slightly
cooler but still hot temps as highs in the 90s are expected.
Isold-sct TS chances will continue as the lee trough interacts
will passing impulses. Main threat from storms will be strong
gusty winds given high LCL`s and inverted V profiles.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Sunday Night)
Issued At 1118 PM MDT Sat Jul 25 2026

Isolated thunderstorms are possible overnight and again Sunday
afternoon and evening. These storms will be high based with gusty,
erratic winds expected. Otherwise VFR conditions will prevail
through the valid forecast period.

&&

.FIRE WEATHER...
Issued At 1008 PM MDT Sat Jul 25 2026

Very hot temperatures will persist into next week
as a ridge of high pressure remains over the region. This will
support elevated to near critical fire weather conditions as RH`s
drop into the teens on the Plains each day. Winds will be
marginal most days, breeziest Sunday on the SD Plains behind a
trough where winds could gust to 30 mph for period. Poor recovery
can also be expected most nights across portions of northeast WY,
the Black Hills, and far western SD given warm overnight lows. In
addition, there will be near daily chances for isolated
thunderstorms as batches of mid level monsoon moisture push
through the region. Storms may produce very little rainfall and
gusty winds, supporting a dry lightning threat at times.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Heat Advisory until 8 PM MDT Sunday for SDZ001-002-012-013-
     025>027-030-031-041-042-072>076-078.
     Extreme Heat Warning until 8 PM MDT /9 PM CDT/ Sunday for SDZ014-
     032-043-044-046-047-049-077.
WY...Heat Advisory until 8 PM MDT Sunday for WYZ054>056-058>060.
&&

$$

UPDATE...13
DISCUSSION...JC
AVIATION...15
FIRE WEATHER...13