Alert archive / Utah / Mesoscale Discussions in 2021

Mesoscale Discussion 1275

July 13, 2021Lincoln County, Nevada; Beaver County, Iron County, Washington County, Utah

The Storm Prediction Center issued this mesoscale discussion at Jul 13, 2021, 4:42 PM PDT for Lincoln County, Nevada; Beaver County, Iron County, Washington County, Utah. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 13, 2021, 4:42 PM PDT (23:42 UTC)
Expired
Jul 13, 2021, 6:45 PM PDT
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
5%

Counties Lincoln County, NV, Beaver County, UT, Iron County, UT, Washington County, UT

The radar

The Las Vegas radar (KESX), 199 km from the middle of the area, began a volume at 23:42 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, 11.7 hours before the alert went out and 128 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 2021-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 492 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 2021-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -83 square meters per square second.1939Sfc1 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
492 J/kg
Mixed-layer CIN
-439 J/kg
Mixed-layer LCL
2245 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
-83 m²/s²
0-3 km storm-relative helicity
-7 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

963 
ACUS11 KWNS 132343
SWOMCD
SPC MCD 132342 
UTZ000-AZZ000-NVZ000-140145-

Mesoscale Discussion 1275
NWS Storm Prediction Center Norman OK
0642 PM CDT Tue Jul 13 2021

Areas affected...Southern NV...Southwest UT

Concerning...Severe potential...Watch unlikely 

Valid 132342Z - 140145Z

Probability of Watch Issuance...5 percent

SUMMARY...Strong wind gusts are possible across southern NV and
southwest UT over the next few hours.

DISCUSSION...Convective cluster moving through northern Lincoln
County NV has shown an increase in southward forward propagation
over the last half hour. Modest instability exists downstream across
southern NV and adjacent southwest UT, suggesting additional
development is possible along this boundary. These additional storms
will develop in an environment characterized by a deeply mixed
boundary layer and modest mid-level moisture. These conditions are
conducive for further outflow development, helping reinforce the
southward surging cold pool already in place. As such, strong wind
gusts are possible across southern NV and southwest UT over the next
few hours.

..Mosier/Thompson.. 07/13/2021

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

ATTN...WFO...SLC...VEF...LKN...

LAT...LON   37361668 37771602 38351422 38491286 37171323 36581515
            36781623 37361668

Nearby

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