Over the past month, the large-scale pattern has featured a persistent trough along the Pacific Northwest coast and a high-amplitude upper-level ridge (a.k.a. the "death ridge") centered over Texas, as shown in the 30-day mean 500-mb height analysis for 17 July – 15 Aug 2011.
However, a subtle but important shift in this pattern is presently underway. Over the past week, troughing over the Pacific Northwest has weakened and the upper-level ridge has built westward into the Intermountain West.
This has brought the longest stretch of days with a maximum temperature above 90F this month and minimum temperatures over the past four days of 70F or greater.
|Source: National Weather Service|
So, the heat is on and we expect maximum temperatures at KSLC to head into the mid–upper 90s by for today, Wednesday and Thursday.