Summer is over (meteorologically), but a late heatwave is going to bake the west for the next week. La Nina is looking likely for this winter. What does it all mean for Utah?
Short Term Forecast
The good news is that summer is officially over, at least meteorologically speaking. June thru August is how we define summer in our world as they are the three hottest months. Unfortunately, Mother Nature doesn't seem to care what the calendar says. Utah (and the rest of the west) is in the midst of a prolonged, unprecedented late-season heatwave which is only adding to our misery.
Summer 2022 in Utah will officially go down as the hottest our state has seen. June and July were hot, but at the end of July we were lagging behind last year's record heat by quite a large margin of 1.9F:
Last year, we had a relatively cool August. This year, we did not. In fact, this August was the 3rd hottest in SLC's history:
Because of this, we were able to catch up and pass last year's summer average temperature and supplant it (and 2017) as the hottest on record (yay!):
It may not sound like it, but 0.6F is quite a decent margin to set a seasonal record. You may notice that 7 of the 10 hottest summers on record have come in the past 10 years. Welcome to the new normal, I suppose.
The good news is that we generally had a healthy monsoon season. 2019 and 2020 were "non-soon" seasons with very little statewide precip. But last year and this year were quite wet. Due to the spotty nature of summer storms, not everybody got good rains, but most of us did. August was quite wet for much of the state, with record rainfall to our west in Nevada:
Summer precip is only a small percentage of our overall water, so even a great monsoon does little to end the drought, but it certainly doesn't hurt. We should have more soil moisture in place heading into the autumn and winter which will help us next year.
Now that it is officially fall, we can expect some cooler temps, right? Normally I would say yes, as September is a much cooler month than August. Not this year! Historically, we almost never saw triple-digit heat in SLC in September. There are only 3 days in our history of 100F temps in September, and two of them are in the past 3 years:
Unfortunately, history doesn't seem to matter anymore. As of right now, it looks highly likely that we will be adding at least a few additional triple-digit days to this list over the next week. There is actually an outside chance that each of the first 7 days of September 2022 will reach 100F at the SLC Airport. If that were to occur, 70% of our triple-digit days ever will have occurred this year. This map showing 7-day temp anomalies of +12.6F over SLC is just nuts:
You may remember that last year (2021) we tied the record for most 100+ days in a year with 21. So far, we've already smashed that record with 27 so far this year and we will likely finish with at least 30, perhaps as high as 34 such days this year. I've run out of adjectives to describe this summer. Let's just say I'm ready for winter...
2022/23 Winter Outlook:
This time of year, I get bombarded with inquiries about the upcoming season. Every year, I am very open about the fact that I have no idea. Nobody does. Seasonal forecasting is next to impossible, especially for mid-latitudes like Utah which do not have strong ENSO correlations. What I can say is that it is looking highly likely that we will have a third consecutive La Nina winter -- a "triple dip". Not often we've seen three such winters in a row so we are somewhat entering new territory. If you want to read more about La Nina and this upcoming winter, I highly recommend this piece my colleague, Sam, wrote last week.
For Utah, it doesn't mean much. The most obvious thing I can say is that we're coming off two La Nina winters and neither one of them was great, so perhaps we will see more of the same. I think, like most La Nina winters, areas farther north stand a better chance at having good snowfall. This is somewhat reflected in NOAA's recently-released first look at the winter months (Dec-Feb):
The one caveat is that this winter could be an even stronger La Nina event -- similar to the epic 2010/11 season. We can dream, right? But really, it's not even worth speculating in my opinion. What will come will come, and we will ride it when it does!
As for my forecasting, I generally post only as needed in September. Sometimes we get early-season storms that have potential to bring snow, so if I see one of those, I will surely update. However, things really start to get going in October so I'd expect a couple of posts per week in October and I'll be back to daily posts no matter what in November. Looking forward to it!
Evan | OpenSnow