Thursday, July 2, 2015

Heat Wave Tidbits

I feel quite disoriented this morning.  I awoke yesterday in Ketchikan, Alaska on a spectacular day.  Temperatures were comfortably in the 60s as we ferried across the Tongass Narrows to the airport.

I arrived yesterday evening at the Salt Lake City airport to an apocalyptic scene.  What the hell did you do to Utah while I was gone?  Where are the green Avenues foothills?  The patches of high mountain snow?  I haven't been gone all that long, but the transformation is dramatic.  

Much has gone on in the past week or two.  We've already spoken quite a bit about the June heat, but how about the air quality?  In Utah, we tend to think about wintertime inversions, but during the summer, our ozone can also become elevated.  Below is a time series of ozone levels on the University of Utah campus over the past 30 days.  Ozone is produced photochemically by the sun's ultraviolet radiation and shows a pronounced diurnal signal with a maximum in the late afternoon and a minimum overnight, as is clearly evident below.  However, you can also see how the peaks were highest during late June during the height of the heat wave.  

Things have been hot in the western United States and Canada, but also western Europe over the past couple of days as an upper level ridge built over the region.

The Weather Channel has a good summary of the weather records here.  98.1ºF at London's Heathrow Airport, which looks to be a July record for the UK (the all-time record is 101.3ºF set in Faversham (Kent) on 10 August 2003).  103.5ºF in Paris (2nd highest all time). 103.5ºF in Madrid (June record).  These are brutal temperatures, especially in northern France and the UK.


  1. Can you comment on the reasons for this heat wave? I've seen reports that SLC was warmer than southern Utah during the past week (and on Monday was the second hottest city in the country after Phoenix), and reports that the far northern Rockies are also warm, but Colorado is not particularly warm. Seems unusual.

  2. The ridge has been centered roughly over Salt Lake City. The core of highest temperatures aloft has also been roughly over Salt Lake City. In recent days monsoonal easterly flow and thunderstorms have moderated temperatures to our south.