Alert archive / Arizona / Mesoscale Discussions in 2021

Mesoscale Discussion 1347

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

The Storm Prediction Center issued this mesoscale discussion at Jul 25, 2021, 4:36 PM MST for Mohave County, Arizona; Clark County, Nevada; Washington County, Utah. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued
Jul 25, 2021, 4:36 PM MST (23:36 UTC)
Expired
Jul 25, 2021, 6:30 PM MST
In force
114 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
5%

Counties Mohave County, AZ, Clark County, NV, Washington County, UT

The radar

The Las Vegas radar (KESX), 94 km from the middle of the area, began a volume at 23:41 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 12:00Z, 11.6 hours before the alert went out and 118 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-pSkew-T log-p diagram, Las Vegas, NV at 12:00Z on 2021-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 97 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Las Vegas, NV at 12:00Z on 2021-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
97 J/kg
Mixed-layer CIN
-248 J/kg
Mixed-layer LCL
2117 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
69 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

714 
ACUS11 KWNS 252337
SWOMCD
SPC MCD 252336 
UTZ000-AZZ000-NVZ000-CAZ000-260130-

Mesoscale Discussion 1347
NWS Storm Prediction Center Norman OK
0636 PM CDT Sun Jul 25 2021

Areas affected...Southwest Utah...northwest Arizona...and southern
Nevada.

Concerning...Severe potential...Watch unlikely 

Valid 252336Z - 260130Z

Probability of Watch Issuance...5 percent

SUMMARY...Cluster of storms may pose a severe wind threat as it
continues southwest.

DISCUSSION...A cluster of cells has developed in southwest Utah and
started to accelerate southwestward. The environment downstream of
this activity is unstable with MLCAPE around 1000 J/kg per SPC
mesoanalysis. Mesoanalysis also shows increasing CINH across this
region which may limit the overall severe threat. However if this
cluster can maintain intensity, it may pose a severe wind threat as
it moves southwestward over the next couple of hours into an area
with DCAPE of 1400 to 1700 J/kg.

..Bentley/Grams.. 07/25/2021

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

ATTN...WFO...FGZ...SLC...VEF...

LAT...LON   37891377 37681304 37431280 37021276 36701285 35801340
            35171385 35031446 35121482 35431526 35591551 35811566
            36061576 36661556 37891377

Nearby

Mesoscale Discussions in Arizona, 2021Mesoscale Discussions in Nevada, 2021Mesoscale Discussions in Utah, 2021Every 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.