Alert archive / Arizona / Mesoscale Discussions in 2021

Mesoscale Discussion 1348

July 25, 2021Mohave County, Arizona; Clark County, Nevada

The Storm Prediction Center issued this mesoscale discussion at Jul 25, 2021, 7:45 PM MST for Mohave County, Arizona; Clark County, Nevada. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued: Jul 25, 2021, 7:45 PM MST (02:45 UTC)
Expired: Jul 25, 2021, 9:15 PM MST
In force: 90 min
Issued by: the Storm Prediction Center
Concerning: Severe potential...watch unlikely
Chance of a watch: 20%

Counties Mohave County, AZ, Clark County, NV

The radar

The Las Vegas radar (KESX), 31 km from the middle of the area, began a volume at 02:50 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.

The nearest sounding before it

Las Vegas, NV (KVEF), launched 00:00Z, 2.8 hours before the alert went out and 119 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 707 J/kg
Mixed-layer CIN: -44 J/kg
Mixed-layer LCL: 2729 m above ground
0-6 km bulk shear: 21 kt
0-1 km storm-relative helicity: 17 m²/s²
0-3 km storm-relative helicity: 81 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

490 
ACUS11 KWNS 260245
SWOMCD
SPC MCD 260245 
AZZ000-NVZ000-CAZ000-260415-

Mesoscale Discussion 1348
NWS Storm Prediction Center Norman OK
0945 PM CDT Sun Jul 25 2021

Areas affected...Southern Nevada and portions of northwest Arizona
and southeast California

Concerning...Severe potential...Watch unlikely 

Valid 260245Z - 260415Z

Probability of Watch Issuance...20 percent

SUMMARY...A cluster of storms capable of severe wind gusts is moving
through southern Nevada.

DISCUSSION...A cluster of storms has continued southwestward and has
become more organized as it moves off of the terrain and toward the
Las Vegas valley. A wind gust of 70 mph was recently measured at
Hoover Dam. Temperatures still remain around 100 degrees in Las
Vegas, which provides ample instability for additional strong
development. Expect some severe wind gusts across southern Nevada in
the next 1 to 2 hours with the chance for a significant (75+ mph)
wind gust where the strongest storm cores collapse. This cluster may
continue to pose a threat for severe wind gusts for a few more hours
but severity should wane as the boundary layer begins to cool.

..Bentley/Grams.. 07/26/2021

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

ATTN...WFO...VEF...

LAT...LON   36641484 36411391 36241350 35831336 35241390 34981422
            34891468 34851500 35091530 35371546 35761563 36641484

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 26, 3:01 PM MST	Mesoscale Discussion	SPC	Lincoln, Nye	119 min

Nearby

Mesoscale Discussions in Arizona, 2021 Mesoscale Discussions in Nevada, 2021 Every mesoscale discussion in 2021

Sources

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