Saturday, June 30, 2018

Numerous Storms Yesterday - Cochise County

Strange, puny little convective tower down toward University yesterday afternoon. The 7-day series of GPS PW from on campus (below) shows we were up to around 30 mm yesterday, but have since crashed back down to about 15 mm.

Considerable thunderstorm activity yesterday over most of Cochise County (above shows detected CG flashes thru midnight last night - from Atmo and Vaisala). The composite radar display below is from a bit after 2:00 pm MST (note the severe thunderstorm warning in effect south of Wilcox).

It was a difficult day for the various forecast models: the 06 UTC WRF-GFS kept the storms across border in New Mexico; the 12 UTC WRF-NAM was similar; but 12 UTC WRF-GFS forecast afternoon storms in northeast part of Cochise County; and then the 18 UTC WRF-NAM caught up with the real world (above is that model's forecast valid at 3:00 pm). But, by the time forecasts were available from that model run, thunderstorms were already occurring. A plot of 24-hour precipitation thru 7:00 am this morning (below, from MesoWest) shows that rain amounts at stations were once again quite light - but the Rucker Canyon RAWS measured 1.48 inches during a storm that also produced gusts to 40 mph, and the Headquarters RAWS site to the north had 0.40 inches. Note the reading at Patagonia is obviously from a station that is having serious problems. Of interest is that a severe thunderstorm impacted the windy Guthrie RAWS site - there was a wind shift to the south there with gusts to 64 mph between 6:00 and 7:00 pm - radar indicated storms in that area at that time.

Finally, down at bottom is the GEFS average 500 mb heights forecast from 00 UTC last evening - valid time is 00 UTC on July 7th. The strength of the large anticyclone that covers the western 2/3 of the of the CONUS is almost frightening. The orientation of the forecast high would tend to block low-level moisture into Arizona from the East Pacific, although some increased PW could work into parts of Arizona from the east.

The Fourth Holiday here will be hot and dry, and then we'll be watching the detailed structures within that monster 500 mb high.

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