Alert archive / Arizona / Mesoscale Discussions in 2021
Mesoscale Discussion 1526
The Storm Prediction Center issued this mesoscale discussion at Aug 14, 2021, 4:34 PM MST for 10 counties in Arizona. It was in force for 116 min.
The area
The outline as issued.
The facts
- Issued
- Aug 14, 2021, 4:34 PM MST (23:34 UTC)
- Expired
- Aug 14, 2021, 6:30 PM MST
- In force
- 116 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
Counties Cochise County, AZ, Gila County, AZ, Graham County, AZ, Greenlee County, AZ, La Paz County, AZ, Maricopa County, AZ, Pima County, AZ, Pinal County, AZ, Santa Cruz County, AZ, Yuma County, AZ
The radar
The Phoenix radar (KIWA), 38 km from the middle of the area, began a volume at 23:33 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, 11.6 hours before the alert went out and 48 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
- 102 J/kg
- Mixed-layer CIN
- -277 J/kg
- Mixed-layer LCL
- 1127 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- 19 m²/s²
- 0-3 km storm-relative helicity
- 161 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.0
The text
As transmitted.
924
ACUS11 KWNS 142334
SWOMCD
SPC MCD 142334
NMZ000-AZZ000-CAZ000-150130-
Mesoscale Discussion 1526
NWS Storm Prediction Center Norman OK
0634 PM CDT Sat Aug 14 2021
Areas affected...Arizona
Concerning...Severe potential...Watch unlikely
Valid 142334Z - 150130Z
Probability of Watch Issuance...5 percent
SUMMARY...Thunderstorms continue this afternoon across the southeast
quadrant of Arizona. Gusty thunderstorm outflows will be possible
with the strongest thunderstorms, but an overall widespread wind
threat is not anticipated. As such a watch is not expected this
afternoon and evening.
DISCUSSION...Showers and thunderstorms continue this afternoon
across the southeast quadrant of Arizona. These thunderstorms are
slowly moving west on the southern periphery of a strong anticyclone
across the Great Basin. Surface temperatures in the low 90s F and
dewpoints in the low 70s F have contributed to upwards of 3000 J/kg
of most-unstable CAPE across central Arizona. Despite this degree of
instability, low-level and mid-level lapse rates are significantly
weaker than in previous days (likely owing to convective overturning
from last night's convection) and not as conducive to downward
momentum transport. This should limit the overall severe wind
potential to localized areas, generally associated with storm-scale
processes. This, combined with high-resolution guidance suggestive
of waning thunderstorm intensity with the loss of diurnal heating
should preclude the need for a watch.
..Marsh/Goss.. 08/14/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...ABQ...EPZ...TWC...FGZ...PSR...VEF...
LAT...LON 32521486 34221452 34531332 34531068 34170940 33590900
31990899 31240914 31251105 32451486 32521486SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 13, 6:55 PM MST | Severe Thunderstorm Watch | SPC | Cochise, Gila, La Paz, Maricopa, Pima, Pinal and 3 more | 8 hr |
| Aug 13, 9:24 PM MST | Mesoscale Discussion | SPC | Gila, La Paz, Maricopa, Pinal, Yuma | 66 min |
| Aug 14, 12:51 AM MST | Mesoscale Discussion | SPC | Yuma | 84 min |
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.