Alert archive / Arizona / Mesoscale Discussions in 2003

Mesoscale Discussion 2020

July 29, 20035 counties in Arizona; Imperial County, California

The Storm Prediction Center issued this mesoscale discussion at Jul 29, 2003, 6:24 PM MST for 5 counties in Arizona; Imperial County, California. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 29, 2003, 6:24 PM MST (01:24 UTC)
Expired
Jul 29, 2003, 8:30 PM MST
In force
2 hr
Issued by
the Storm Prediction Center

Counties La Paz County, AZ, Maricopa County, AZ, Pima County, AZ, Pinal County, AZ, Yuma County, AZ, Imperial County, CA

The radar

The Yuma radar (KYUX), 137 km from the middle of the area, began a volume at 01:23 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

Phoenix, AZ (KPSR), launched 00:00Z, 1.4 hours before the alert went out and 135 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, Phoenix, AZ at 00:00Z on 2003-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 523 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, Phoenix, AZ at 00:00Z on 2003-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 12 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
523 J/kg
Mixed-layer CIN
-98 J/kg
Mixed-layer LCL
2122 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
12 m²/s²
0-3 km storm-relative helicity
79 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

573 
ACUS11 KWNS 300124
SWOMCD
SPC MCD 300124 
AZZ000-CAZ000-300330-

MESOSCALE DISCUSSION 2020
NWS STORM PREDICTION CENTER NORMAN OK
0824 PM CDT TUE JUL 29 2003

AREAS AFFECTED...SRN AZ/SERN CA

CONCERNING...SEVERE THUNDERSTORM WATCH 815...

VALID 300124Z - 300330Z

LINE OF STRONG TO SEVERE THUNDERSTORMS WILL CONTINUE TO PROPAGATE 
WWD INTO SCENTRAL AZ/PHX METRO AREA DURING THE NEXT 2 HOURS WITH
DAMAGING WIND THE PRIMARY THREAT.  

RECENT SURFACE ANALYSES INDICATED AROUND 3 MB/HR PRESSURE RISES AT
TUS. THE STRENGTH OF THE OUTFLOW COMBINED WITH RELATIVELY UNCAPPED
MODERATELY UNSTABLE AIRMASS...MLCAPES AROUND 1000 J/KG PER 00Z
PHOENIX SOUNDING...SHOULD CONTINUE TO AID IN NEW CONVECTIVE
DEVELOPMENT ON THE LEADING EDGE. STEEP LOW LEVEL LAPSE RATES WILL
FAVOR DAMAGING WINDS WITH THE STRONGEST CONVECTION. DEGREE OF DEEP
LAYER SHEAR WITH WLY INFLOW AIR BELOW 25 KT MID LEVEL WINDS MAY
SUPPORT ENOUGH STORM ROTATION FOR MARGINALLY SEVERE HAIL. FARTHER
WEST...IF A SUFFICIENTLY STRONG COLD POOL DEVELOPS FROM SEVERAL
STORM MERGERS OVER SWRN AZ IN THE NEXT 1-2 HOURS BEFORE ONSET OF
INCREASING INHIBITION...THEN A NEW WW MAY BE NEEDED FOR PORTIONS OF
SERN CA.

..CROSBIE.. 07/30/2003

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

ATTN...WFO...TWC...FGZ...PSR...VEF...

31771166 32341435 32741557 34661552 34491414 33501048

Nearby

Mesoscale Discussions in Arizona, 2003Mesoscale Discussions in California, 2003Every mesoscale discussion in 2003

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.