Miscellany For 4 And 5 August

Some may not have noticed, but the Nogales airport had a very severe thunderstorm yesterday at about 2:30 pm MST. The storm produced gusts to 71 mph and 1.43 inches of rain in about an hour.
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No rain during past 24 hours in the ALERT network, except for two stations that caught some rain from a line of sunrise showers that was oriented south-to-north, just off to the east of town. Not much rain from these shallow buildups, but a spectacular, burning orange sunrise resulted.

Yuma  (see T and Td time series above) had a very strange surface dewpoint "surge" yesterday, with the dewpoint jumping from 26F to 70F between 1 and 3 pm. But, by 5 pm the dewpoint had fallen back to 31F. This strange "diurnal surge" had little impact on the GPS PW trace, so it was quite shallow and gone as quickly as it came.

The Tucson sounding this morning (above) continues to display some CAPE for the afternoon, and especially for higher elevations. The moisture that came in with the Dora surge event has drifted around south-central and southeastern Arizona for a couple of weeks now - thanks primarily to the nearly calm winds that have persisted in the lower half of the troposphere. Note that there is an ugly dry layer centered around 700 mb this morning (it is deeper and more pronounced in the Phoenix sounding), if it mixes into the surface-based, afternoon BL, there will be much less CAPE than indicated by the SPC diagnostics.

The above figure is the Tucson morning hodograph from SPC. This graphic shows light/variable winds all the way up to 9 km - not a good situation at all.

The U of A Atmo early run of the WRF indicates another day with activity at high elevations and along the borderlands. The plot about is WRF-GFS accumulated rainfall through midnight tonight.
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The morning run of the NWS NAM model forecasts the large 500 mb anticyclone to maintain two separate centers, with a weak shear zone between the two lobes of the high, stuck over southeastern Arizona through 48 hours. However by 60 hours, the two centers consolidate, in the forecast, into a single, large anticyclone centered just off to the northeast of Tucson. Can anyone find anything that's positive for a substantial, areal increase in storm and rain activity?