A dramatic increase in thunderstorm activity yesterday, as shown by plot above of CG flashes through 11:00 pm MST last night (from Vaisala and Atmo). There were several reports of wind damage around the metro area -Atmo had a gust to about 50 mph and we had about the same here at the house. The time-series below is from Atmo and shows the 25 F temperature drop that came with the storm outflow.
Across the ALERT network there were 59 sites with measured rainfall (~60 percent) for the 24-hours ending at 6:00 am this morning. There were 18 stations with half an inch or more and 7 stations with more than an inch. The Rillito Wash flowed at some time during the night. Here at the house we had thunder and wind but only a couple of spits of rain - Trace. Plot below shows the 24-hour rainfall for the metro-west sector, where there was a very sharp rain/no rain boundary.
This morning skies have mostly cleared (above visible image is from 6:30 am) except to the east, where there is significant cloud cover with a weak inverted trough at 500 mb - this feature will be moving slowly westward across our area today. The morning TWC sounding (below for 12 UTC) shows considerable cooling below 850 mb and considerably less CAPE than was present yesterday. There are northeasterly winds ( not very strong) below 400 mb, so perhaps there will be a bit more storm movement toward the west today. It may take an organized outflow from the east to southeast to get storm development at low elevations. There will be some distinct thermal boundaries playing a role, since soil is very wet in places and bone dry in others. The morning run of the NWS NAM forecasts a wet day for southeast Arizona - bottom panel shows NAM forecast of rainfall through 8:00 pm MST this evening.
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