Alert archive / Nevada / Mesoscale Discussions in 2004

Mesoscale Discussion 2017

August 16, 2004Mohave County, Arizona; 4 counties in Nevada; Iron County, Washington County, Utah

The Storm Prediction Center issued this mesoscale discussion at Aug 16, 2004, 10:54 AM MST for Mohave County, Arizona; 4 counties in Nevada; Iron County, Washington County, Utah. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Aug 16, 2004, 10:54 AM MST (17:54 UTC)
Expired: Aug 16, 2004, 1:00 PM MST
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Mohave County, AZ, Clark County, NV, Lincoln County, NV, Nye County, NV, White Pine County, NV, Iron County, UT, Washington County, UT

The nearest sounding before it

Mercury/Desert R, NV (KDRA), launched 12:00Z, 5.9 hours before the alert went out and 68 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: 242 J/kg
Mixed-layer CIN: -221 J/kg
Mixed-layer LCL: 1524 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 101 m²/s²
0-3 km storm-relative helicity: 161 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

246 
ACUS11 KWNS 161755
SWOMCD
SPC MCD 161754 
UTZ000-AZZ000-NVZ000-CAZ000-162000-

MESOSCALE DISCUSSION 2017
NWS STORM PREDICTION CENTER NORMAN OK
1254 PM CDT MON AUG 16 2004

AREAS AFFECTED...SRN AND CENTRAL NV...FAR SERN CA...NWRN AZ AND SWRN
UT

CONCERNING...SEVERE THUNDERSTORM POTENTIAL 

VALID 161754Z - 162000Z

THE FIRST FEW ATTEMPTS AT THUNDERSTORMS ARE DEVELOPING OVER THE MTNS
OF FAR SRN NV...IN A REGION OF STRONG LARGE SCALE ASCENT AHEAD OF
UPPER LOW CENTERED OVER NRN NYE COUNTY. ADDITIONAL CONVECTION IS
ANTICIPATED TO OCCUR OVER THE HIGHER TERRAIN OF FAR SERN CA...NWRN
AZ AND SWRN UT. 

RECENT FORECAST SOUNDINGS AND MODIFIED 12Z DRA SOUNDING INDICATE
THAT ONLY 30-50 J/KG OF CINH REMAIN OVER THE AREA AND THAT THREAT
FOR ISOLATED SEVERE STORMS SHOULD BEGIN BY AROUND 19Z. BELT OF 20-25
KT WSWLY MID LEVEL FLOW SHOULD REMAIN OVER THE AREA GIVEN
ORGANIZATION OF THE LOW OVER CENTRAL NV. NELY LOW LEVEL WINDS A
RESULT OF GRADIENT BETWEEN SFC HIGH CENTERED OVR NRN NV AND LOW
TROUGH OVER SERN CA SHOULD SUPPORT AROUND 30-35 KTS OF DEEP LAYER
SHEAR. GIVEN STEEP LAPSE RATES...LOW WBZ HEIGHTS AND MODERATE
INSTABILITY WITH 1000-1500 J/KG OF MLCAPE...EXPECT AT LEAST ISOLATED
SUPERCELL STORMS WITH LARGE HAIL THE PRIMARY THREAT. ALTHOUGH LESS
DEEP LAYER SHEAR IS ANTICIPATED OVER NRN/CENTRAL NV...STEEP LAPSE
RATES AND COLD TEMPS ALOFT WILL FAVOR AT LEAST
MARGINALLY SEVERE HAIL IN THIS AREA.

..CROSBIE.. 08/16/2004

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

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

34871609 36061656 36751632 37181627 38001670 38911726
39891661 39861535 38661350 37401279 36051289 35091329
34741417 34681567

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 16, 10:39 AM MST	Mesoscale Discussion	SPC	Cochise, Graham, Greenlee, Maricopa, Pima, Pinal and 1 more	66 min

Nearby

Mesoscale Discussions in Nevada, 2004 Mesoscale Discussions in Utah, 2004 Mesoscale Discussions in Arizona, 2004 Every mesoscale discussion in 2004

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.