Alert archive / Arizona / Mesoscale Discussions in 2012

Mesoscale Discussion 770

May 9, 2012Pima County, Pinal County, Santa Cruz County, Arizona

The Storm Prediction Center issued this mesoscale discussion at May 9, 2012, 5:31 PM MST for Pima County, Pinal County, Santa Cruz County, Arizona. It was in force for 89 min.

The area

The outline as issued.

The facts

Issued
May 9, 2012, 5:31 PM MST (00:31 UTC)
Expired
May 9, 2012, 7:00 PM MST
In force
89 min
Issued by
the Storm Prediction Center
Chance of a watch
5%

Counties Pima County, AZ, Pinal County, AZ, Santa Cruz County, AZ

The radar

The Tucson radar (KEMX), 83 km from the middle of the area, began a volume at 00:34 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

Tuscon, AZ (KTUS), launched 00:00Z, 0.5 hours before the alert went out and 54 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, Tuscon, AZ at 00:00Z on 2012-05-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Tuscon, AZ at 00:00Z on 2012-05-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -72 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2528 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
-72 m²/s²
0-3 km storm-relative helicity
50 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.

200 
ACUS11 KWNS 100031
SWOMCD
SPC MCD 100031 
AZZ000-100200-

MESOSCALE DISCUSSION 0770
NWS STORM PREDICTION CENTER NORMAN OK
0731 PM CDT WED MAY 09 2012

AREAS AFFECTED...SRN AZ

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 100031Z - 100200Z

PROBABILITY OF WATCH ISSUANCE...5 PERCENT

SUMMARY...A SEVERE THREAT MAY CONTINUE ACROSS SRN AZ AS CELLS MOVE
SWWD ACROSS THE REGION. HAIL AND STRONG WIND GUSTS WILL BE POSSIBLE
WITH THE MORE INTENSE CELLS. THE THREAT SHOULD REMAIN TOO MARGINAL
TO WARRANT THE ISSUANCE OF A WATCH.

DISCUSSION...A SHORT LINE OF STRONG THUNDERSTORMS IS CURRENTLY
ONGOING ON THE EAST SIDE OF THE PHOENIX METRO AREA. THE ACTIVITY IS
LOCATED ON THE NRN EDGE OF AN ANALYZED POCKET OF MODERATE
INSTABILITY WITH MLCAPE IN THE 1000 TO 1200 J/KG. REGIONAL WSR-88D
VWPS ACROSS SE AZ SHOW 40 TO 45 KT OF DEEP LAYER SHEAR. THIS
COMBINED WITH MID-LEVEL LAPSE RATES ESTIMATED IN THE 8.0 TO 8.5 C/KM
RANGE SHOULD SUPPORT A THREAT FOR HAIL WITH THE STRONGER CORES. IN
ADDITION...STEEP LOW-LEVEL LAPSE RATES WITH LARGE SFC TEMP-DEWPOINT
SPREADS OF 40 TO 50 DEGREES F MAY HELP ENHANCE DOWNDRAFT SPEEDS
RESULTING IN A MARGINAL WIND DAMAGE THREAT. THESE SEVERE THREATS MAY
CONTINUE FOR ABOUT 2 MORE HOURS BEFORE DIMINISHING WITH WEAKENING
INSTABILITY.

..BROYLES/HART.. 05/10/2012

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

ATTN...WFO...TWC...PSR...

LAT...LON   33151206 32701260 32231274 31901251 31391193 31131138
            31051089 31161058 31421039 32081041 32701045 33281114
            33151206

Nearby

Mesoscale Discussions in Arizona, 2012Every mesoscale discussion in 2012

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.