The forecast for the next week is ugly. Persistently dry, hot weather of the variety that I despise.
Today will probably be the coolest day of the next week. The GFS 700-mb (roughly 10,000 ft above sea level) temperature forecast below shows the highest temperatures over western North America moving over Utah this weekend and then remaining until at least 1200 UTC (0600 MDT) 21 August when I decided not to look any farther out.
Afternoon 700-mb temperatures are above 18˚C in northern Utah on some afternoons, such as 0000 UTC 19 August (1800 MDT Tuesday).
This is exceptional warmth for mid August. In the upper-air sounding record for the Salt Lake City International Airport, the highest 700-mb temperature on record is 20.2˚C (measured at 0000 UTC 13 July). After 10 August, however, the highest 700-mb temperature on record is 18.4˚C. 
Consistent with the GFS forecast, the National Weather Service has issued an Excessive Heat Watch for Sunday Afternoon through Wednesday Evening for the Wasatch Front and much of Utah. Note that there is potential for the heat wave to extend beyond that.
Below is their forecast for the Salt Lake City International Airport, with highs of 100 or more on Sunday, Monday, and Tuesday and in the upper 90s Wednesday and Thursday.
The record highs on Sunday, Monday, and Tuesday are 100, 100, and 99, so we have a shot at setting daily records. The highest temperature observed after August 10th is 103 on August 20, 1960.
About the only good thing about a heat wave this deep in August is that the days are shorter, which means the blistering sun sets earlier and rises later, making the mornings and evenings a bit more pleasant, with the longer night sometimes giving us lower minimum temperatures.
Nevertheless, I'm not looking forward to this heat wave.
That watch was upgraded to a warning for most valleys, including the Wasatch Front. I don't think I've ever seen that before. Even the mountain valleys, which were left out of the official NWS alerts for the last heatwave, are under a heat advisory this time.
ReplyDeleteNWS's afternoon forecast discussion even mentions the potential for KSLC to make a run at the August or even all-time record highs.