I'll be doing the Atmo weather discussion at 11:30 am this morning, and I'll just give a brief accounting here of the pros and cons I see in the charts and forecasts this morning.
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PROS - the visible satellite image (top) shows that much of the Southwest and Mexico is clear this morning. However, the local are here remains under fairly heavy middle cloud. Yesterday the cloud proved extremely peristent, and loops this morning show that it is barely moving. thus, many areas will get much better heating today - locally we'll have to watch the clouds.
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The PW is quite high (45 to 50 mm) at the low-elevation sites in southern Arizona and the morning sounding (middle image) indicates better CAPE likely this afternoon, so an upturn is likely today relative to the dismal situation yesterday.
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Although upper-level flow appears strongly confluent this morning, the NAM forecasts show that by evening the flow aloft becomes difluent over southern Arizona.
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CONS - the wind field through much of the troposphere over the Southwest and Mexico remains very chopped-up and light and variable. Thus, a serious lack of steering level winds and also poor vertical shear, except over northern Arizona and the Great Basin.
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Surface pressures are 4 to 6 mb higher than they were 48 to 72 hours ago.
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Southeastern Arizona appears stuck under a weak shear zone between two lobes of the 500 mb anticyclone that is moving little (see 500 mb analysis from RAP at bottom).
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Thus somewhat of a coin toss for the southeast part of state today, with storms being very locally driven and propagating somewhat randomly. Best storm settings today definitely to the north and west of our area.
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An aside, for the second time this summer, the soundings at San Diego have CAPE above the marine layer and there were some storms in the southern California mountains yesterday. I also see that GoC low-level moisture has finally made it to Las Vegas and desert Rock - too bad that we have such a massive hole in the upper-air data out that way.
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