Alert archive / Arizona / Mesoscale Discussions in 2011

Mesoscale Discussion 2152

September 9, 201111 counties in Arizona

The Storm Prediction Center issued this mesoscale discussion at Sep 9, 2011, 1:00 PM MST for 11 counties in Arizona. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued: Sep 9, 2011, 1:00 PM MST (20:00 UTC)
Expired: Sep 9, 2011, 2:30 PM MST
In force: 90 min
Issued by: the Storm Prediction Center

Counties Cochise County, AZ, Coconino County, AZ, Gila County, AZ, Graham County, AZ, La Paz County, AZ, Maricopa County, AZ, Mohave County, AZ, Pima County, AZ, Pinal County, AZ, Santa Cruz County, AZ, Yavapai County, AZ

The radar

The Phoenix radar (KIWA), 60 km from the middle of the area, began a volume at 20:01 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 12:00Z, 8.0 hours before the alert went out and 46 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: 54 J/kg
Mixed-layer CIN: -469 J/kg
Mixed-layer LCL: 3036 m above ground
0-6 km bulk shear: 36 kt
0-1 km storm-relative helicity: 103 m²/s²
0-3 km storm-relative helicity: 187 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.

381 
ACUS11 KWNS 092001
SWOMCD
SPC MCD 092000
AZZ000-NVZ000-CAZ000-092130-

MESOSCALE DISCUSSION 2152
NWS STORM PREDICTION CENTER NORMAN OK
0300 PM CDT FRI SEP 09 2011

AREAS AFFECTED...MUCH OF CNTRL/SRN AZ

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 092000Z - 092130Z

THUNDERSTORMS WILL INCREASE IN INTENSITY AND COVERAGE THROUGH THE
AFTERNOON. ALTHOUGH WIDESPREAD ORGANIZED SEVERE WEATHER IS NOT
ANTICIPATED AT THIS TIME...A FEW STRONGER STORMS COULD PRODUCE
MARGINALLY SEVERE HAIL OR STRONG/GUSTY WINDS.

WIDESPREAD THUNDERSTORMS WERE DEVELOPING ACROSS MUCH OF ARIZONA THIS
AFTERNOON AIDED BY PLENTY OF MIDLEVEL MONSOONAL MOISTURE IN PLACE
AND AN UPPER LEVEL DISTURBANCE NOTED ON WV IMAGERY OVER NERN AZ.
ASIDE FROM THIS RELATIVELY WEAK UPPER LEVEL FEATURE...ENVIRONMENTAL
CONDITIONS ARE NOT OVERLY SUPPORTIVE OF WIDESPREAD SEVERE WEATHER
TODAY. HOWEVER...SOME ENHANCED DEEP LAYER SHEAR DOES EXIST WITH
AROUND 25-35 KT EFFECTIVE BULK SHEAR ACROSS CNTRL AND SRN AZ.
COMBINED WITH MLCAPE VALUES INCREASING TO 1000-2000 J/KG...THIS
COULD HELP SUSTAIN SOME UPDRAFTS LONG ENOUGH TO LEAD TO A MARGINAL
HAIL THREAT /ESPECIALLY GIVEN STEEP MID LEVEL LAPSE RATES/...OR A
STRONG WIND GUST FROM TIME TO TIME GIVEN LARGE SFC
TEMPERATURE-DEWPOINT SPREADS /30-40 DEGREES F/ AND STEEP LOW LEVEL
LAPSE RATES.

..LEITMAN.. 09/09/2011

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

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

LAT...LON   32680941 33600988 34661039 35071068 35551108 35791155
            35891201 35861256 35841334 35691410 35511447 35131462
            34471443 34091426 33221379 32361312 31841232 31501106
            31451024 31450996 31600966 31900933 32680941

Nearby

Mesoscale Discussions in Arizona, 2011 Every mesoscale discussion in 2011

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.