Alert archive / Arizona / Mesoscale Discussions in 2021

Mesoscale Discussion 1250

July 10, 20216 counties in Arizona

The Storm Prediction Center issued this mesoscale discussion at Jul 10, 2021, 6:55 PM MST for 6 counties in Arizona. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 10, 2021, 6:55 PM MST (01:55 UTC)
Expired
Jul 10, 2021, 9:00 PM MST
In force
2 hr
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 369

Counties Gila County, AZ, Graham County, AZ, Maricopa County, AZ, Pima County, AZ, Pinal County, AZ, Santa Cruz County, AZ

The radar

The Phoenix radar (KIWA), 49 km from the middle of the area, began a volume at 01:58 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, 1.9 hours before the alert went out and 79 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 2021-07-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 965 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 2021-07-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 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
965 J/kg
Mixed-layer CIN
-311 J/kg
Mixed-layer LCL
3378 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
116 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.0

Open this sounding in Storm Lab

The text

As transmitted.

453 
ACUS11 KWNS 110155
SWOMCD
SPC MCD 110155 
AZZ000-110400-

Mesoscale Discussion 1250
NWS Storm Prediction Center Norman OK
0855 PM CDT Sat Jul 10 2021

Areas affected...Central and southeastern Arizona

Concerning...Severe Thunderstorm Watch 369...

Valid 110155Z - 110400Z

The severe weather threat for Severe Thunderstorm Watch 369
continues.

SUMMARY...Storms continue to move off the higher terrain in central
and southeastern Arizona. Severe wind gusts are the primary threat
with these storms, though isolated large hail is also possible.

DISCUSSION...Storm coverage along the Mogollon Rim into southeastern
Arizona has increased early this evening. These clusters of storms
are expected to continue to move off the higher terrain and pose a
threat for severe winds gusts. The strongest gusts so far have
occurred in southeastern Arizona. The cluster is moving roughly
westward, the main portion of which may reach south of Tucson later
this evening. Additional development has occurred in northwestern
Cochise County and could impact western portions of Pima County as
well.

Northeast of Phoenix, a nearly contiguous line of thunderstorms
continues to move south/southwest off of the Mogollon Rim. Current
timing of the line suggest it may impact portions of the Phoenix
Metro between 9-10 PM MST. Severe wind gusts as well as isolated
large hail will be possible.

..Wendt.. 07/11/2021

...Please see www.spc.noaa.gov for graphic product...

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

LAT...LON   33841262 34251190 34381122 33681005 32700977 32051014
            31621048 31411098 31601146 32491237 33311274 33841262

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 11, 1:23 PM MSTSevere Thunderstorm WatchSPCCochise, Graham, Greenlee8 hr
Jul 11, 3:59 PM MSTMesoscale DiscussionSPCGila, Yavapai2 hr

Nearby

Mesoscale Discussions in Arizona, 2021Every mesoscale discussion in 2021

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.