Alert archive / Arizona / Mesoscale Discussions in 2021
Mesoscale Discussion 1244
The Storm Prediction Center issued this mesoscale discussion at Jul 10, 2021, 2:48 PM MST for 4 counties in Arizona. It was in force for 117 min.
The area
The outline as issued.
The facts
- Issued
- Jul 10, 2021, 2:48 PM MST (21:48 UTC)
- Expired
- Jul 10, 2021, 4:45 PM MST
- In force
- 117 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch possible
- Chance of a watch
- 60%
Counties Cochise County, AZ, Gila County, AZ, Graham County, AZ, Pinal County, AZ
The radar
The Phoenix radar (KIWA), 79 km from the middle of the area, began a volume at 21:49 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Tuscon, AZ (KTUS), launched 12:00Z, 9.8 hours before the alert went out and 98 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.
- Mixed-layer CAPE
- 1505 J/kg
- Mixed-layer CIN
- -302 J/kg
- Mixed-layer LCL
- 1767 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 22 m²/s²
- 0-3 km storm-relative helicity
- 60 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
964
ACUS11 KWNS 102148
SWOMCD
SPC MCD 102148
AZZ000-102345-
Mesoscale Discussion 1244
NWS Storm Prediction Center Norman OK
0448 PM CDT Sat Jul 10 2021
Areas affected...Central and southeastern Arizona
Concerning...Severe potential...Watch possible
Valid 102148Z - 102345Z
Probability of Watch Issuance...60 percent
SUMMARY...Storms are continuing develop along the Mogollon Rim and
Gila Mountains. As these storms are beginning to move off the
terrain, a threat for strong to severe wind gusts is increasing for
the lower deserts. A WW is possible this afternoon.
DISCUSSION...Temperatures in the lower deserts of central/southern
Arizona have risen to 105-110 F while maintaining upper 50s to low
60s F dewpoints. A cluster of storms has developed within the Gila
mountains and has shown a tendency to move southwestward off the
terrain given 25-30 kts of cloud-bearing shear. The 13Z observed PHX
sounding sampled 1.61 inches PWAT with very steep mid-level lapse
rates. Further development is possible along other portions of the
Mogollon Rim as well as within southeastern Arizona. A cluster or
two of thunderstorms is expected to evolve this afternoon and
evening. Some MLCIN is still being objectively analyzed, but cold
pool development should help parcels reach their LFC and continue to
propagate southwestward. Steep lapse rates through the lower
troposphere will promote strong to severe wind gusts. Though
clustering will likely occur quickly, discrete activity will pose a
marginally severe hail threat. A WW is possible this afternoon.
..Wendt/Thompson.. 07/10/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...TWC...FGZ...PSR...
LAT...LON 33241208 33651249 34341225 34391153 34231026 33670934
33060925 32040942 31551003 31531075 31631097 33241208SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 9, 10:21 PM MST | Mesoscale Discussion | SPC | Maricopa, Pinal | 54 min |
| Jul 10, 4:52 PM MST | Severe Thunderstorm Watch | SPC | Gila, Maricopa, Pima, Pinal | 7 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.