Alert archive / California / Mesoscale Discussions in 2004

Mesoscale Discussion 2012

August 15, 2004Inyo County, San Bernardino County, California; Esmeralda County, Nevada

The Storm Prediction Center issued this mesoscale discussion at Aug 15, 2004, 2:38 PM PDT for Inyo County, San Bernardino County, California; Esmeralda County, Nevada. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Aug 15, 2004, 2:38 PM PDT (21:38 UTC)
Expired
Aug 15, 2004, 4:45 PM PDT
In force
2 hr
Issued by
the Storm Prediction Center

Counties Inyo County, CA, San Bernardino County, CA, Esmeralda County, NV

The nearest sounding before it

Mercury/Desert R, NV (KDRA), launched 12:00Z, 9.6 hours before the alert went out and 122 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, Mercury/Desert R, NV at 12:00Z on 2004-08-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 132 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, Mercury/Desert R, NV at 12:00Z on 2004-08-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 67 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
132 J/kg
Mixed-layer CIN
-93 J/kg
Mixed-layer LCL
1859 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
67 m²/s²
0-3 km storm-relative helicity
140 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

554 
ACUS11 KWNS 152138
SWOMCD
SPC MCD 152138 
NVZ000-CAZ000-152345-

MESOSCALE DISCUSSION 2012
NWS STORM PREDICTION CENTER NORMAN OK
0438 PM CDT SUN AUG 15 2004

AREAS AFFECTED...SRN SIERRA NEVADA...PORTIONS OF SERN CA AND SWRN NV

CONCERNING...CONVECTIVE TRENDS 

VALID 152138Z - 152345Z

UPPER LOW CENTERED OVER CENTRAL CA HAS INTENSIFIED OVER THE LAST FEW
HOURS...AS A MID/UPPER LEVEL SPEED MAX ROTATES INTO THE BASE OF THE
TROUGH. ENHANCED MID/HIGH LEVEL FLOW COUPLED WITH MODERATE
INSTABILITY SHOULD AID IN AN INCREASING TREND IN CONVECTIVE STRENGTH
OVER THE AREA THROUGH THE REST OF THE AFTERNOON. OVERALL STORM
ORGANIZATION SHOULD BE LIMITED ENOUGH THAT SVR THREAT SHOULD REMAIN
RELATIVELY MARGINAL.

LATEST SATELLITE IMAGERY INDICATES JET RELATED CIRRUS STREAKS
RAPIDLY MOVING EWD OVER THE SRN CENTRAL VALLEY/CENTRAL COAST REGION.
UPPER LOW CENTERED NEAR MERCED HAS SHOWN SIGNS OF INTENSIFICATION IN
RESPONSE TO THIS ENHANCEMENT OF FLOW. INCREASING UPPER DIFFLUENT
FLOW SHOULD ALLOW FOR CONTINUED STORM INTENSIFICATION OVER THE SRN
SIERRA NV SWD INTO SWRN NV AND SERN CA. AROUND 30 KTS OF CLOUD
BEARING SHEAR AND 1500-2000 J/KG OF MLCAPE IS ANTICIPATED TO ALLOW
FOR SOME STORM ROTATION AND STRONG ENOUGH UPDRAFTS TO SUPPORT
MARGINALLY SVR HAIL/DAMAGING WINDS. IN ADDITION...SLOW STORM MOTIONS
AND ELY UPSLOPE FLOW ESPECIALLY OVER THE HIGH DESERT REGION OF SWRN
NV/SERN CA...WILL AID IN LOCALLY HEAVY RAINFALL RATES ABOVE 1 IN/HR.

..CROSBIE.. 08/15/2004

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

ATTN...WFO...PSR...VEF...SGX...REV...HNX...LOX...

35211821 35841831 36861852 37211875 37541893 37911859
37871766 37241647 36681557 36271525 34871497 34241505
34001555 33951596 34411739

Nearby

Mesoscale Discussions in California, 2004Mesoscale Discussions in Nevada, 2004Every 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.