Mesoscale Discussion 1721

Issued

Jul 24, 2026, 1:02 PM MDT (19:02 UTC)

Expired

Jul 24, 2026, 3:00 PM MDT

In force

118 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

20%

Counties Bannock County, ID, Bingham County, ID, Blaine County, ID, Bonneville County, ID, Butte County, ID, Caribou County, ID, Cassia County, ID, Fremont County, ID, Gooding County, ID, Jefferson County, ID, Jerome County, ID, Lincoln County, ID, Madison County, ID, Minidoka County, ID, Power County, ID, Teton County, ID, Twin Falls County, ID

The Pocatello radar (KSFX), 43 km from the middle of the area, began a volume at 19:04 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

297 
ACUS11 KWNS 241902
SWOMCD
SPC MCD 241902 
IDZ000-UTZ000-NVZ000-242100-

Mesoscale Discussion 1721
NWS Storm Prediction Center Norman OK
0202 PM CDT Fri Jul 24 2026

Areas affected...Southeast Idaho and portions of far northeast
Nevada and northwest Utah

Concerning...Severe potential...Watch unlikely 

Valid 241902Z - 242100Z

Probability of Watch Issuance...20 percent

SUMMARY...Isolated thunderstorms capable of producing strong to
severe downburst winds will spread across southeast Idaho through
early evening. This threat will remain sufficiently limited to
preclude watch issuance.

DISCUSSION...Latest GOES imagery and lightning data show steady
vertical growth of cumulus and the early stages of convective
initiation across far northeast NV, northwest UT, and south-central
ID. Continued development is expected through mid-afternoon as
daytime heating and orographic ascent strengthens and any lingering
inhibition is eroded. Immediately downstream from this activity,
temperatures are warming into the mid 90s and low 100s with
dewpoints mixing into the upper 40s and low 50s. Although RAP
mesoanalyses suggests MLCAPE has only increased to around 500 J/kg,
modifying a recent 18 UTC LKN based on downstream observations
suggests MLCAPE has actually increased to around 1000 J/kg.
Consequently, a few robust thunderstorms will likely emerge in the
coming hours. 

The potential for strong/severe downburst winds should increase as
this activity spreads into the hotter, more deeply mixed environment
air mass within the Snake River Plain - largely driven by the
propensity for downdraft accelerations through a ~3 km deep boundary
layer. This scenario is reflected in recent HRRR/RRFS solutions,
which depict the potential for downbursts winds on the order of
55-70 mph. Despite this potential, modest deep-layer wind shear
(sampled by the 18 UTC LKN sounding) suggests that storm modes will
most likely remain poorly organized and transient, which limits
confidence on the overall coverage/duration of the severe threat and
the need for watch issuance.

..Moore/Smith.. 07/24/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...SLC...PIH...BOI...LKN...

LAT...LON   41731501 42011522 42221534 42641526 42911499 44281208
            44311167 44211138 44011124 43611113 43191115 42921135
            42521186 41561452 41731501 

MOST PROBABLE PEAK WIND GUST...55-70 MPH

Mesoscale Discussions in Idaho, 2026Every mesoscale discussion in 2026

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; radar from the NEXRAD Level II archive.