This morning there is much cloudiness around the west side of the central US anticyclone, primarily affecting eastern Arizona at 1430 UTC (above). There are some light showers associated with the cloudiness. There was another dust event in the Phoenix area yesterday. Low-level moisture has yet to show up in southwest Arizona. Storms yesterday produced mostly wind and dust (gusts of 30 to 50 mph were common) at lower elevations, with heaviest rain amounts in and near mountains. A bit more than 60% of the ALERT gauges had rainfall, with 5 sites having more than 1/2 an inch. The greater Tucson gauges had 25% coverage with the greatest rainfall amount at only 0.12". Here at house we had light showers around 2 pm MST, but with only a Trace of rainfall - didn't observe lightning or thunder here.
The morning sounding at Tucson (above) appears slightly more moist at low levels (PW values are right around 1.5" across southern Arizona), but still with limited CAPE at low elevations. Winds have weakened through most of the troposphere, with no substantial steering flow peresent. Mountain CAPE again appears to be considerably greater than that at low desert elevations. So, there appears to be a greater threat of heavy rains over higher elevations today, since storms will probably just wander around, moving toward nearby unstable air.
The U of A Atmo version of high-resolution WRF model did quite well yesterday, and it appears to be forecasting pretty much what is written above for today. The WRF-GFS run from midnight predicts storms over the mountains around Tucson by 2 pm (top graphic is composite radar forecast). The cloudy area this morning has convection, but later in afternoon and evening (note that the model did foreast the morning clouds and showers quite well). Bottom panel shows the forecast of total rainfall amounts by 10 pm tonight.
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