Tuesday, July 23, 2019

Quick Summary 22 July


Composite radar images for 4:27 pm MST yesterday (above) and 6:45 am this morning (below). Heavy thunderstorms yesterday (much as forecast by WRF model runs at Atmo) produced local heavy rains and strong wind gusts. There were six reports of severe (greater than 50 kt) or wind damage in Pima and Santa Cruz Counties - including a gust to 66 mph at DM. Didn't see any tree damage during my morning walk.

Storms here occurred right around dusk with much thunder, lightning flashes, and light rains - estimate winds at 40 to 45 mph. 

Radar below indicates light showers in our area this early morning.



Map of detected CG flashes (above, from Atmo and Vaisala) is for 24-hours ending at  2:00 am this morning - an active day from the Rim south across our area.

Rainfall was widespread across ALERT network (below shows northern portions) - only 1 site did not measure 0.04". There were 7 sites with over an inch and 21 sites with a half inch or more.


The 12 UTC sounding plot for TWC (below) shows effects of convection yesterday below 700 mb. There is elevated CAPE from 700 to 600 mb, and this is probably feeding the morning showers. Wind profile is chopped up - strongest east winds near surface and in 400 to 200 mb layer. Layer of south winds reflect an MCS over Santa Cruz County.

The current WRF forecasts have not handled the morning convection accurately - only the 06 UTC WRF-NAM had morning showers but intensity was much too strong. Given the morning convection and convectively modified sounding, this afternoon remains to be seen. But activity usually much reduced after a round of strong storms the day before.


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