Brief Outlook:
Isolated thunderstorms are expected across parts of Arizona tomorrow, particularly in central and southern regions. These storms will be capable of producing strong winds, heavy rainfall, and localized flash flooding.
Region Impacted: Central and Southern Arizona
Upper-Level Forecast/Dynamics:
An upper-level ridge will continue to dominate the weather pattern over the southwestern United States, leading to a return of monsoonal moisture into Arizona. This ridge will allow for the influx of moisture from the south, enhancing the potential for thunderstorms, especially during the afternoon and evening hours. Although the ridge will limit widespread storm development, areas of stronger instability combined with weak upper-level disturbances could trigger isolated thunderstorms especially to the east and southeastern portions.
Surface Conditions:
At the surface, instability values are expected to reach 1000-1500 J/kg across central and southern Arizona, fueled by warm temperatures and increased low-level moisture with dewpoints in the mid-60s. Effective shear will be moderate, supporting the development of isolated thunderstorms, particularly in the higher terrain. The steep mid-level lapse rates will promote strong updrafts, which could lead to the formation of stronger storm cells capable of producing gusty winds and heavy rainfall. The storm activity will likely be of the isolated nature, with a few cells possibly organizing into small clusters.
Timing:
Storms are expected to initiate by early afternoon (around 1-3 PM MST) in southern and southeastern Arizona, with activity increasing in coverage as the day progresses and spreading by late afternoon and early evening. Peak intensity is likely to occur from mid-afternoon through the early evening, with the strongest thunderstorms expected during this period. The storms are likely to weaken by late evening as the atmosphere stabilizes. A round of scattered showers, and perhaps an isolated thunderstorm, is also possible overnight across central Arizona.
Main Impact: gusty winds, heavy rainfall, hail and lightning.
Sina⚡⚡
Co-Owner/CTO and Lead Forecaster of NWF Innovations & NWF Networks