Summer Weather Report

A week's worth of weather--the first official week of summer-- as reported on the Weather Underground site is enough to fill the entire newspapers that mostly ignore it.

Last Sunday, the US Southeast was in the midst of a sweltering heat wave.  On Tuesday, reports of at least 12 damaging tornadoes in the High Plains and Midwest.  Severe thunderstorms hit the Northeast on Wednesday. On Thursday, storms caused significant damage and caused widespread power failures in Missouri.  Today a huge dust storm hit Phoenix, and flooding in the Midwest killed two while also causing power failures.

Meanwhile an extreme heat wave had settled into the interior Pacific northwest from northeastern California as far north as British Columbia.  Records for June highs were broken in many locations, and significantly for this area, so were record high nightime lows--that is, things didn't really cool off as much as they usually do at night there (Portland, Oregon for instance.)  Moreover, the conditions causing this heat weren't changing, and were likely to persist into July--breaking records for the length of the heat wave as well as its intensity.  The summer fire season in these regions is already far advanced to what used to be midsummer levels.

And incidentally, heat waves in Pakistan have killed more than 1200 people, with more heat and more deaths expected.

Studies announced this week included one that showed that summers in every region of the US have been getting hotter consistently since 1970.  There's an interactive map to illustrate it.

Another study: Scorching summertime heat waves in Europe, Asia and North America, as well as extreme cold snaps in central Asia, have become more likely because of changes in the way air is flowing over those regions, a new study detailed in the journal Nature suggests.

The exact relationship of these changes in atmospheric patterns to global heating from greenhouse gases emissions is yet to be determined.  Is it causal or interactive? Do the two phenomena have different causes that tend to reinforce, exaggerate or counter effects of the other?  At this point it seems that the effects vary from place to place.  But for most places, it adds to the heat of hotter summers.