Gillette, Wyoming 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

545
FXUS63 KUNR 250013
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
613 PM MDT Fri Jul 24 2026

.KEY MESSAGES...

-Blocking pattern will support a large ridge of high pressure
 over the CONUS this weekend into next week, with very hot
 temperatures and fire weather concerns

-Thunderstorms will be possible at times this weekend into next
 week as monsoon impulses advect around the ridge and into the
 region

-Critical fire weather conditions Sat with high based dry
 thunderstorms possible along with low RH and dry fuels

&&

.DISCUSSION...(This Evening Through Friday)
Issued at 1221 PM MDT Fri Jul 24 2026

Upper level ridge over the Rockies will shift east and expand
over the central CONUS. This will result in very hot temperatures
this weekend into next week. Batches of mid level monsoon moisture
will advect through the region as near daily waves eject out of
the Rockies and into the FA. Upper level wave and trailing sfc
trough now progressing across North Dakota and MT. This system may
support a few isolated showers or storms across NW SD in the
afternoon, continued a low pop for this. A separate weak impulse
may also support a shower or storm across northeast WY in the
evening , but the chances for any convection making it into the FA
are very slim and have left pops out. Main item of concern will
be the large ridge of high pressure that will build into the
region. Upper ridge will shift east Sat with very hot temps
expected. Highs will reach 100 or higher for most locations on the
Plains, supporting adv level heat index readings. Low level
moisture will deplete some with mixing, but sustained southerly
flow will prevent the BL from drying out too much most places.
This will help keep heat index readings higher, esp over central
SD. Heat looks to persist most of next week although highs will
trend more toward the mid and upper 90s as opposed to the 100s
like this weekend. Have issued a heat adv through Sunday when the
core of he heat is expected. The adv will be marginal out in
northeast WY where very dry BL conds and slightly lower temps will
keep heat index values in the 95 to 100 range. In addition to the
heat, expect near daily TS chances as monsoon moisture advects
around the NW side of the ridge. This includes Sat when a stronger
monsoon wave will advect around the ridge in SW flow and into the
FA, supporting high based TS chances. Gusty winds will be
possible with any thunderstorms in this period given very high
based nature and resultant inverted-V profiles per drying BL. Sct
wind gusts over 50 mph (likely higher in stronger cells) will be
possible give DCAPE of 1500-2000 J/KG. Not much rain expected with
these cells, which will support critical fire weather conds when
coupled with dry fuels and low RH. Ridge will retrograde back west
some by mid next week, supporting slightly cooler but still hot
temps, with isold-sct TS chances continuing as the lee trough
interacts will passing impulses.

&&

.AVIATION...(For the 00Z TAFS Through 00Z Saturday Evening)
Issued At 612 PM MDT Fri Jul 24 2026

VFR conditions are expected through the forecast period.

&&

.FIRE WEATHER...
Issued At 1221 PM MDT Fri Jul 24 2026

Very hot temperatures return this weekend and will persist into
next week as a ridge of high pressure builds over the region. This
will support elevated to critical fire weather conditions as RH`s
drop into the teens on the Plains each day. Winds will be
marginal most days, except for perhaps far Western SD Sunday when
gusts to 30 will be possible. 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. This is especially the case Saturday
afternoon and evening across northeast WY and western SD. TS`s
will produce very little rainfall and gusty/erratic winds. Wind
gusts over 50 mph will be possible with any cells, potentially
higher. Given high potential for dry TS, min RH`s of 15 to 20
percent, very dry fuels, and gusty erratic winds have issued a red
flag warning for Sat.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...Heat Advisory from noon MDT /1 PM CDT/ Saturday to 8 PM MDT /9
     PM CDT/ Sunday for SDZ001-002-012>014-025>027-030>032-
     041>044-046-047-049-072>078.
     Red Flag Warning from noon Saturday to midnight MDT Saturday
     night for SDZ319>333.
WY...Heat Advisory from noon Saturday to 8 PM MDT Sunday for
     WYZ054>056-058>060.
     Red Flag Warning from noon Saturday to midnight MDT Saturday
     night for WYZ314>318.
&&

$$

DISCUSSION...JC
AVIATION...15
FIRE WEATHER...JC