MD 1620 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR PORTIONS OF SOUTHERN ARIZONA
Mesoscale Discussion 1620
NWS Storm Prediction Center Norman OK
0335 PM CDT Sun Jul 31 2022
Areas affected...portions of southern Arizona
Concerning...Severe potential...Watch unlikely
Valid 312035Z - 312230Z
Probability of Watch Issuance...5 percent
SUMMARY...Clusters of thunderstorms should continue to propagate
northwest with a risk for isolated damaging outflow gusts this
afternoon. Severe potential is expected to remain localized and a
weather watch is unlikely.
DISCUSSION...As of 2030 UTC, regional radar analysis showed a
cluster of multi-cell thunderstorms ongoing across southern AZ near
the international border. Rich monsoon moisture (surface dewpoints
in the mid to upper 60s F) and warm temperatures are contributing to
1500-2000 J/kg of MLCAPE estimated from the modified 18z Tucson, AZ
RAOB. While buoyancy will remain favorable for strong updrafts, area
VAD/VWPs show vertical shear is weak, generally less than 25 kt. The
limited shear should favor a multi-cell storm mode with limited
organization potential. Though a few stronger downdrafts may emerge
given the relatively evaporative cooling within the dry low-levels
and coalescing outflow. Additional storm development along the
flanks of the current cluster and off of the higher terrain farther
southeast may also pose an isolated damaging wind risk into this
evening. However, given the lack of greater storm organization
potential, a weather watch is not expected.
..Lyons/Grams.. 07/31/2022
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...TWC...FGZ...PSR...
LAT...LON 32151373 33231333 33651284 33941234 34001196 33771166
33201124 32831077 32431022 32341000 31960982 31640971
31380971 31240971 31261106 31351146 31551202 32151373
