Storms Returning

View toward the eastern Catalinas at 5:40 am MST this morning.

Plot of detected CG flashes (above - from Atmo and Vaisala) through 0733 UTC last night shows some storm activity on mountains and east side of the metro area.

ALERT data for 24-hours ending at 7:00 am (above) shows amounts over 0.04" along Redington Pass. While plot from MesoWest for same period (below) shows some lighter amounts in the east metro area.

Gusty winds were a concern yesterday with 4 severe reports in southeast Arizona (see SPC site), with strongest being gusts to 79 mph at Safford's airport. The Tucson airport had gusts to 49 mph; Atmo reported 36 mph; and I estimated gusts of 30 to 40 mph from the east here.

At 500 mb this morning (analysis above) the main anticyclone is centered over the Great Basin, keeping winds north to northeasterly over much of Arizona. However, by 12 UTC on Saturday (06 UTC GFS forecast below), the anticyclone is forecast to shift eastward over northeastern Utah, putting most of Arizona under easterly winds aloft.

The morning upper-air sounding from TWC/TUS (above) remains dry and not very favorable for storms. Steering flow would try to bring storms off the mountains into portions of the metro area again this afternoon and evening. Graphic from the NWS Forecast Office (below) indicates increasing storm coverage and intensities through the weekend.