Tuesday, July 12, 2016

Wasn't That Pleasant

Yesterday wasn't a record setter at the Salt Lake Airport, but it was unusually cool for a sunny day and remarkably pleasant.  As a friend commented to me last night, "isn't September wonderful in Salt Lake City."  It sure is.

For the average temperature for the day, one has to go back to 1983 to find a July 11 with a lower average temperature.

Source: NOAA Regional Climate Centers
For the maximum temperature, one has to go back to 1951 for a tie and 1936 for something lower.

Source: NOAA Regional Climate Centers
Most impressive to me is that the cool temperatures were associated with sunny skies rather than a rainy monsoon surge.  "Ah, what an airmass" as one of my former professors liked to say.

But alas, September is over.  The good news is that it really doesn't look that bad the next couple of days with highs in the upper 80s (maybe mid 80s tomorrow).  The bad news is that we will be back to more seasonable weather (i.e., highs in the 90s) later in the week, possibly for the long haul.  You can't stop July.  You can only hope to contain it.

6 comments:

  1. Do you have any idea why this happened? A cold air mass north and west made it's way here? How far north and how far west--I'm thinking arctic air that warmed a bit as it moved into Utah? Anything to do with the typhoons in the Phillipines, Nepartak last week and Butchoy this week? Any thoughts on whether climate change is causing this--circulation patterns, sea temps and such? Or is it more or less "normal" weather, which will always have 80 year cool events every 80 years?

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    1. As is the case with extreme weather, there are usually multiple factors at play. I didn't notice a clear connection with the typhoons, but the airmass did appear to be of high-latitude origins and it's southward penetration was related to mid-latitude cyclogenesis and associated ridge building over the north Pacific (diving the colder air southward). The temperatures we observed were unusually cool, but I don't consider the factors to be freakish.

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    2. The main trough brushed along the western and southern coastlines of Alaska (starting in the Bering Sea) then moved southeast through the Gulf of Alaska and merged with another trough before it moved inland. I don't think it was anything too unusual for the Pacific Northwest (July snowfall events above 8,000 feet happen every several years or so in WA/OR/ID) but it reached a bit further south than usual because of its size.

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    3. Thanks David, helpful in trying to figure out how this happened. Yeah, in 1985 I got snowed 6 inches mid-July at 4000 feet in Central Idaho. So are you saying Monday's air w daytime high of 75 in Salt Lake originated in the Bering Sea? Of course, any given air mass over the Bering Sea comes from somewhere else, the Arctic, the Phillipines etc. Ultimately it's all global circulation?

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    4. That's where the low center was when I first looked at it in the satellite loop. Forecast models showed this also if you look back in time.

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  2. Was it record low of 17 degrees F for peter sinks?

    http://twdef.usu.edu/Peter_Sinks/Temperature-summary.html

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