Thunderstorms moved across the metro area after midnight this early morning. Image above shows CG flash over northeast Catalinas. Radar below (from NCAR RAL) is for 0658 UTC - about the time of the flash shown. The plot of detected CG flashes (second below - for 24-hours ending at 1203 UTC) shows a focus of thunderstorm activity over eastern Pima County (from Atmo and Vaisala).
Rainfall was widespread across the ALERT array with a considerable number of reports of 0.50" and more. Here at house there was 0.32", which fell after midnight. I was doubtful that the BL could recover after the rain of the 7th - but models were better (although about 6 hours too early), and I was wrong.
There were also a number of severe thunderstorms in Arizona yesterday. There were 6 reports of large hail (greater than inch in diameter) around Sierra Vista. There were also 7 reports of severe winds around Buckeye, west of Phoenix, where mesonet stations recorded gusts over 75 mph.
The 500 mb chart is quite interesting this morning (above) because of the nearly complete lack of height gradients. Looks like height range from California to Southeast is only from 588 to 593 dm. The western anticyclone circulation center is about over Lake Powell. The morning TWC/TUS sounding (below, from SPC) is distinctly onion shaped. Afternoon heating will probably lead to a BL with almost no CAPE.
So, I am again in the position of doubting the model forecasts. The 09 UTC WRF-RR forecasts for composite radar echoes above is valid at 7:00 pm MST this evening, while forecast below shows the model's total rainfall through midnight tonight. Will the models prevail again today?
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