Widespread Storms Over Much Of Arizona On The 14th

We were away at Santa Rita Abbey for the last day and a half (5 miles northwest of Sonoita) - so no reports real-time on yesterday's storms. Photo above is of the Santa Rita Mountains looking toward the west at about 6:30 am on Saturday.

The photo below is looking south at the updraft bases of building cumulus at 11:00 am yesterday morning. By noon heavy storms were to the south and we could hear rumbles of thunder. These storms moved overhead around 1 pm MST, but with only light rain and some lightning and thunder - as new storms built to the north. Chased away the rain down there too.

Thunderstorms were widespread across Arizona yesterday, with locally heavy downpours and some reports of severe storms. Here in the Tucson area during past 24-hours the reports indicate: TUS 0.77", Davis-Monthan AFB 0.12", Atmo 0.04", and here at house only 0.02". Across the ALERT network 80 of 93 sites had rainfall (more than 85% areal coverage). There were 21 gauges with a half inch or more and 9 sites had more than an inch. The heavy amounts were in the area of the Catalinas and Rincon Mountains and the far south part of the network. The storms developed early yesterday, and by early evening almost all the storm activity was over the northern half of the state.

This morning PW remains high across most of southern Arizona, although TUS is at about 1.6 inches which is down from the very high 1.8" of yesterday. The TUS sounding for 12 UTC this morning (Sunday, July 15, 2012) is shown on skewT plot above (from Univ. of Wyoming web site). The sounding still has CAPE at low levels. But there is a deep layer of cool, storm-modified air that extends from the surface up to 750 mb - this is not good. A new boundary layer (BL) will have to build over lower elevations and this new BL will have considerable capping above. So, strong outflow forcing will be needed to get storms to build off the mountains (much like Friday, when the Tucson area storms hugged the mountains and avoided lower elevations). Winds aloft are mostly south-southeasterly to southwesterly at 15 to 25 mph. This profile is not good for many locations, as anvils from mountain storms are blown out ahead of the storms - unless the cell manages to move faster than upper-level winds. Definitely not a good wind profile for here at the house.

The early WRF-GFS forecast indicates storm development later in the afternoon, and tends to keep strongest storms at higher elevations. The model forecast of composite radar echoes is shown above, valid at 4 pm MST. Model-predicted total rainfall through midnight tonight is shown below. The house is located in the light blue area (<1/10") just north of the 0.3 amount indicated at Atmo. I'll hope for a better amount than this, although the forecast looks pretty good to me.