Tuesday, August 21, 2018

20 August - Storms Return To Parts Of Metro

It is a very complex situation this morning, and I'll come back to today a bit later. First though is a recap of yesterday. 

Above shows very heavy thunderstorm northwest of Kitt Peak at 6:44 pm MST yesterday afternoon. Below is composite radar display from 5:00 pm. At that time storms were trying to move across the metro area from the mountains, while there was a larger area of storms off to southwest of Tucson. It appeared as if thunderstorms were going to develop nearly overhead here, but they slowly dissipated and also shifted off toward the south. So, there was some distant thunder and a couple of very slight sprinkles - Trace.

The plot of detected CG flashes above (from Atmo and Vaisala for 24-hours ending at 6:30 am this morning) shows interesting developments during the night. The yellows and greens are yesterday afternoon's thunderstorms - these mostly avoided much of the metro and were most active to southwest. However, the reds to white show flashes that occurred from around midnight on - these storms developed east of Tucson and moved north-northwestward during the early morning hours and were still very active at sunrise. Although storms moved into eastern Maricopa County, they mostly avoided the low elevations of the Phoenix metro area.

Two plots below are ALERT rainfall maps for 24-hours ending at 7:00 am this morning - I broke the display into two pieces. Over the northern part of network the storms stayed mostly on Catalinas and Rincons. Storms that tried to come into the northeast metro just died out, producing some very light rain and a fairly classic donut hole effect.

Many more stations in southern part of the network had measurable rainfall. It appears that a significant storm developed southeast of the airport and moved toward west-northwest (this storm can also be seen in the CG flash plot above).

The airport reported thunderstorms with 0.07" and also a wind gust to 56 mph, while DM had thunder but only a Trace with gusts to 29 mph. There were reports of severe winds with damage southwest of the airport in the San Xavier Mission area.

More  re today in a while.

No comments:

Post a Comment