Alert archive / California / Mesoscale Discussions in 2004

Mesoscale Discussion 2003

August 14, 2004Riverside County, San Bernardino County, California; Clark County, Nevada

The Storm Prediction Center issued this mesoscale discussion at Aug 14, 2004, 1:16 PM PDT for Riverside County, San Bernardino County, California; Clark County, Nevada. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Aug 14, 2004, 1:16 PM PDT (20:16 UTC)
Expired: Aug 14, 2004, 3:45 PM PDT
In force: 2 hr
Issued by: the Storm Prediction Center

Counties Riverside County, CA, San Bernardino County, CA, Clark County, NV

The radar

The Santa Ana Mts radar (KSOX), 117 km from the middle of the area, began a volume at 20:15 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

San Diego, CA (KNKX), launched 12:00Z, 8.3 hours before the alert went out and 166 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1071 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -40 m²/s²
0-3 km storm-relative helicity: -11 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.

773 
ACUS11 KWNS 142017
SWOMCD
SPC MCD 142016 
NVZ000-CAZ000-142245-

MESOSCALE DISCUSSION 2003
NWS STORM PREDICTION CENTER NORMAN OK
0316 PM CDT SAT AUG 14 2004

AREAS AFFECTED...SRN CA AND FAR SRN NV

CONCERNING...HEAVY RAINFALL 

VALID 142016Z - 142245Z

VERY HEAVY RAINFALL WITH TRAINING STORMS IS EXPECTED ALONG THE CHAIN
OF THE COASTAL MTNS FROM NERN LOS ANGELES COUNTY INTO ERN SAN DIEGO
COUNTY. RAINFALL RATES FROM 1-2 INCHES PER HOUR ARE LIKELY.
ADDITIONAL HEAVY RAINFALL IS ANTICIPATED ALONG THE ERN/SRN SIDES OF
OTHER MTNS IN THE MOJAVE DESERT REGION OF SERN CA AND FAR SRN NV.

SATELLITE IMAGERY SHOWS A NEARLY STATIONARY UPPER VORT CENTER
LOCATED OVER FAR SRN NV TO THE SOUTH OF LAS VEGAS. MODEST NELY MID
LEVEL FLOW AND BACKED ELY LOW LEVEL WINDS WILL SUPPORT A VERY STRONG
UPSLOPE PATTERN INTO THE ERN SLOPES OF THE MTNS OF SRN CA. VERY
MOIST AIRMASS WITH DEWPTS IN THE MID 60S UP TO 3000 FT...PW VALUES
FROM 1.5 TO 1.8 INCHES PER REGIONAL 18Z SOUNDINGS ALONG WITH
MODERATE INSTABILITY AND SLOW SWD STORM MOTIONS...WILL AID IN STRONG
CONVECTIVE DEVELOPMENT AND TRAINING OF HEAVY RAINFALL INTO THESE
MTNS. CONVECTION SHOULD BE MAINTAINED ALONG THE ERN SLOPES OF THE
MTNS IN SRN CA AND THE SRN SLOPES OF MTNS IN FAR SRN NV AND FAR ERN
SAN BERNARDINO COUNTY THROUGH MUCH OF THE AFTERNOON DUE TO THE
STATIONARY NATURE OF THE MID/UPPER LEVEL FORCING.

..CROSBIE.. 08/14/2004

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

ATTN...WFO...PSR...VEF...SGX...LOX...

32551638 33881691 34301803 34581800 34831752 36471567
36491472 33961489 33501622 32551601

Nearby

Mesoscale Discussions in California, 2004 Mesoscale Discussions in Nevada, 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; radar from the NEXRAD Level II archive.