tag:blogger.com,1999:blog-6168620747792092240.post7289683176997963073..comments2024-03-27T15:09:59.039-06:00Comments on Wasatch Weather Weenies: Salt Lake's July "Human Misery Index" Is ClimbingJim Shttp://www.blogger.com/profile/15799757451626876963noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-6168620747792092240.post-3439671754135310812018-07-16T10:07:57.488-06:002018-07-16T10:07:57.488-06:00There are two primary factors contributing to the ...There are two primary factors contributing to the ongoing persistent drought over the southwest. The first is a lack of precipitation. The second is the high temperatures, which yields greater evapotranspiration (and also has effects on snowpack and runoff). Most of the evidence that I have seen suggests that the lack of precipitation is probably a reflection of internal variability, or what you call a "cycle". It may have happened with or without climate change. However, the warmth is being amplified by climate change and this is essentially a "drought multiplier" due to more rapid evapotranspiration. <br /><br />In the past there is strong evidence of persistent drought over the southwest. However, the warming that has been and will continue to occur means that we need to be cautious using past droughts as inferred from proxy records (e.g., tree rings) as an analog for future drought. In particular, during dry periods, drought will come on faster and be more severe in the future. <br /><br />JimJim Shttps://www.blogger.com/profile/15799757451626876963noreply@blogger.comtag:blogger.com,1999:blog-6168620747792092240.post-25385919619598799492018-07-14T23:36:38.094-06:002018-07-14T23:36:38.094-06:00It may be useful to compare this trend in minimum ...It may be useful to compare this trend in minimum temperatures to the corresponding (or perhaps just the daily maximum) dew point values, if a graph of dew point trends can be obtained. A lot of nocturnal cooling may be related to surface evaporation, especially in irrigated areas in a dry climate, and therefore to the amount of watering around the measurement site and in the area as a whole. I would speculate that a large-scale change from irrigated grass to rockscapes, etc is a big deal for urban area minimum temps. SLC is a good place to observe these trends because of its dry climate and the location of KSLC relative to noctural prevailing winds over the urban area. Davidhttps://www.blogger.com/profile/02814313368731066590noreply@blogger.comtag:blogger.com,1999:blog-6168620747792092240.post-30713766402304575082018-07-12T14:07:02.539-06:002018-07-12T14:07:02.539-06:00praying gets ya nothing.praying gets ya nothing.unknownbloggerhttps://www.blogger.com/profile/04664462609268490651noreply@blogger.comtag:blogger.com,1999:blog-6168620747792092240.post-16217298502968884192018-07-12T11:45:35.424-06:002018-07-12T11:45:35.424-06:00To your list of reasons for the recent increase in...To your list of reasons for the recent increase in number of days with minimum above 70 I would add the drought we have been discussing the past few months. There is speculation climate change is causing or at least intensifying the drought. Recalling the DeRose et al data for the Bear River, we would expect the decline in flow since 2000 to be associated with the increase in overnight lows we have been experiencing in July in Salt Lake. My guess is Julys in Salt Lake when the Anasazi disappeared during the 1200s were similarly miserable to what we are now experiencing. My hope, and we'll see how futile it is as the future plays out, is that we are not in the beginning of a 50 or 100 year drought and that we will cycle into a wetter cooler period in the next few years. We can only pray, ehPeter Donnerhttps://www.blogger.com/profile/07658400081780668829noreply@blogger.comtag:blogger.com,1999:blog-6168620747792092240.post-87637955757012790242018-07-11T20:08:09.332-06:002018-07-11T20:08:09.332-06:00By coincidence (?), the Times today ran an equally...By coincidence (?), the Times today ran an equally depressing story on the increase in average low temperatures: https://www.nytimes.com/interactive/2018/07/11/climate/summer-nights-warming-faster-than-days-dangerous.html?hp&action=click&pgtype=Homepage&clickSource=story-heading&module=second-column-region&region=top-news&WT.nav=top-newsDerek Hoffhttps://www.blogger.com/profile/13788619739997805477noreply@blogger.com