Flash Flood Watch Today

View of Catalinas about 6:10 am MST this morning.

The NWS has issued a flash flood watch for today, after yesterday's widespread rain event (see graphic at bottom).

ALERT plots of rainfall recorded for 24-hours ending at 7:30 am this morning.with heaviest amounts in the mountains. Rains started around 7:00 pm and continued into the nighttime hours. Here at the house we had 0.47" with occasional rumbling thunder. The plot (second below) of detected CG flashes shows a bit of a Tucson donut hole but lightning we observed here was in-cloud. Other rain amounts: Atmo 0.54"; DM 0.20" and TUS 0.15".

At 500 mb the closed low off the Pacific coast is moving inland across northern California. However the southern part of the trough weakens and remains offshore, not crossing the Southwest, in model forecasts.

The morning TWC sounding (below) is interesting, since lowest layers are cool. It is not clear how deep the BL will grow, given the mostly cloudy skies. The layer around 700 mb has CAPE and the depth of the afternoon BL may not matter. The 12 UTC WRF-RR forecast (from Atmo) for rain through 5:00 am tomorrow morning (second below) keeps the focus of rainfall over eastern Pima County. Regardless, last evening's rain here was much needed and appreciated.