FXUS63 KUNR 080434
AFDUNR

Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
1034 PM MDT Tue Jul 7 2026

.KEY MESSAGES...

-Active through mid week as a series of disturbances move through
 the region, with severe thunderstorms possible today, more 
 isolated Wed and Thur

-Very hot this weekend into early next week with record high 
 temps possible and dangerous heat

&&

.DISCUSSION...(This Afternoon Through Monday)
Issued at 1025 AM MDT Tue Jul 7 2026

Impulse filled westerly flow will be in place over the region 
through Thursday as a frontal boundary remains in place. Near 
daily chances for thunderstorms can be expected with severe storms
possible at times, best chances today. Sfc front stalled across 
the FA today. The front has settled further south that previous 
model runs indicated yesterday, with a southward shift of the best
severe potential. Moderately strong impulse will kick out of 
WY/MT in the the afternoon and evening and will drive CI there. 
Storms may also fire along the Pine Ridge and INVOF of the front 
if capping can be overcome. Another location for CI will be 
northern BH if the inhibition is also overcome. Given progged ML 
CAPE of 1-2.5 KJ/KG, deep bulk layer shear of 35 to 45 knots 
(highest north of the sfc front), expect supercells to be possible
with strong rotating updrafts, capable of producing large hail 
and damaging winds. Best chances for rotating storms will be along
and north of the sfc front. Still a very small window for 
tornadoes with any storms near the sfc front, which will start 
shifting SW into SW SD this afternoon. Storms will carry across 
the region through the evening and overnight, possibly lingering 
into the morning Wed as elevated activity. More storms are 
possible Wed and Thur as sufficient LL moisture will be in place 
with weak stability and additional impulses. The best chances for 
storms will be across the western third Wed with chances expanding
to the entire FA Thur. Upper ridge builds into the region this 
weekend, with dry and hot conds expected. Impressive temps of 35 
to almost 40C at h85 with close to 6000 H5 heights over WY, will 
offer record to near record highs well into the 100s with 110 to 
115 possible on portions of the Plains, esp Sunday and Monday. 
Ridge begins to breaks down across the Northern Plains the middle 
of next week, with storm chances returning as the active northern 
periphery of the ridge settles south.

&&

.AVIATION...(For the 06Z TAFS Through 06Z Wednesday Night)
Issued At 1032 PM MDT Tue Jul 7 2026

Thunderstorms will continue move across western South Dakota over
the next couple of hours. Frequent lightning and gusty/erratic 
winds can be expected with any stronger convective cores. 
Transient MVFR/IFR conditions also expected around any heavier 
precipitation cores. Conditions will begin to improve around 09z 
as storms diminish and move out of the region. Areas of lower 
ceilings and patchy fog may develop over northwestern South Dakota
between 06z and 17z; MVFR/IFR conditions are possible. 

Another round of storms will begin to develop over northeast
Wyoming and western South Dakota starting around 08/19z and 
lasting through the remainder of the forecast period.

&&

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

$$

DISCUSSION...JC
AVIATION...Schultz