Alert archive / Nevada / Mesoscale Discussions in 2021
Mesoscale Discussion 1126
The Storm Prediction Center issued this mesoscale discussion at Jun 29, 2021, 2:51 PM PDT for Inyo County, Mono County, Tuolumne County, California; 6 counties in Nevada; Washington County, Utah. It was in force for 84 min.
The area
The outline as issued.
The facts
- Issued
- Jun 29, 2021, 2:51 PM PDT (21:51 UTC)
- Expired
- Jun 29, 2021, 4:15 PM PDT
- In force
- 84 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
Counties Inyo County, CA, Mono County, CA, Tuolumne County, CA, Clark County, NV, Esmeralda County, NV, Lincoln County, NV, Lyon County, NV, Mineral County, NV, Nye County, NV, Washington County, UT
The radar
The Las Vegas radar (KESX), 207 km from the middle of the area, began a volume at 21:54 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, 9.9 hours before the alert went out and 123 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.
- Mixed-layer CAPE
- 41 J/kg
- Mixed-layer CIN
- -205 J/kg
- Mixed-layer LCL
- 3715 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 19 m²/s²
- 0-3 km storm-relative helicity
- 38 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
884
ACUS11 KWNS 292152
SWOMCD
SPC MCD 292151
UTZ000-AZZ000-NVZ000-CAZ000-292315-
Mesoscale Discussion 1126
NWS Storm Prediction Center Norman OK
0451 PM CDT Tue Jun 29 2021
Areas affected...Eastern California into the Southern Great Basin
and portions of the Southwest
Concerning...Severe potential...Watch unlikely
Valid 292151Z - 292315Z
Probability of Watch Issuance...20 percent
SUMMARY...High-based storms across portions of Nevada, Utah,
Arizona, and eastern California may pose a risk for strong downdraft
winds or a dry microburst this afternoon and evening. Coverage of
severe storms should remain low enough that a weather watch is not
needed.
DISCUSSION...One the fringes of a powerful mid-level anticyclone
centered over the Pacific Northwest, weak forcing for ascent has
overspread monsoonal moisture across portions of the Great Basin and
Southwest. Scattered thunderstorms have been observed to develop and
strengthen over the last half hour. These storms are ongoing in an
environment characterized by steep mid and low-level lapse rates
around 8-9 C/km. With a relatively high PWAT airmass (0.75-1.1
inches) in place, between 500-1000 J/kg of MUCAPE has developed.
This will continue to support robust updraft development through the
rest of the diurnal cycle. Overall vertical shear remains weak, with
a local maximum between 20 and 25 kts across southeastern Nevada and
western Utah. The lack of greater shear should favor a multicellular
storm mode, with the potential for isolated severe gusts as updrafts
collapse through this evening. Given limited storm organization and
expected severe coverage, a watch is not expected.
..Lyons/Guyer.. 06/29/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...SLC...VEF...LKN...REV...HNX...STO...
LAT...LON 35421450 36021833 38042010 39101943 39291701 38961536
38661419 38121349 37471322 36861328 36441336 35421450Nearby
Mesoscale Discussions in Nevada, 2021Mesoscale Discussions in California, 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.