Dry and Hot

I'm back in town after a quick trip to Boulder and the National Center for Atmospheric Research.  Apparently I missed out on the "big" precipitation event, which gave us a trace of rain Monday at the Salt Lake City International Airport.  That may have ended our stream of days without precipitation, but the streak of days without measurable precipitation continues.

Source: NWS

There is a very real chance that we will make it through June without measurable precipitation.  Only a rogue convective storm could ruin that streak.

We are now about to enter what should be a hot stretch.  We mentioned a few days ago that the GFS was going for extremely warm temperatures for later this week, with forecast 700-mb temperatures near 20ºC, which is on the outer edge of our current climatology (I emphasize current because higher temperatures are coming in future decades).  The good news is that the latest forecast are slightly cooler, putting the 700-mb temperature for Friday afternoon near 18–19ºC, but the bad news is that's still damn hot.

I mentioned in that earlier post that days with 700-mb temperatures near or above 20ºC are very rare (note: we use 700-mb, which is at about 10,000 feet, as an indicator of the overall warmth of the airmass).  Trevor Alcott of the National Weather Service recently sent me some numbers illustrating that this is truly the case.  In fact, days above 19ºC are pretty exceptional, as can be inferred from the 10 highest 700-mb temperatures observed at the Salt Lake City airport since 1956.

Courtesy Trevor Alcott

Here are the peak 700-mb temperatures forecast by the GFS for the approximate time of the upper-air soundings on Friday, Saturday, Sunday, and Monday afternoons:

Friday: 18.2ºC

Saturday: 19.1ºC

Sunday: 19.5ºC

Monday: 19.2ºC

Yup, that's rarified air, probably good for maximum temperatures at the airport in the triple digits.  Nasty!  In addition, I need to note that this is JUNE (Monday is July), and all the top-10s above are in July and August.  So, this is especially rarified air for this early in the year.  We'll have to keep an eye on things to see if we can break into the top-10 for all-time 700-mb temperature.  If you are keeping score at the ground, the records at the airport for Friday Saturday, and Sunday, are 102, 104, and 103, respectively.