It feels like autumn outside and there’s no sign of a long warm & dry spell ahead. Fall is here which has worked out just about right this year.
Officially fall arrives weather-wise on September 1st according to NOAA & the National Weather Service. Traditionally of course we think of it starting with the Autumnal Equinox late next week. Regardless, as meteorologists we consider summer to be June-July-August so let’s take a look back at Summer 2019. The numbers might surprise you.
First, let’s get this out of the way…
THIS SUMMER WAS WARMER THAN AVERAGE WEST OF THE CASCADES
That includes both urban and rural areas. Even now I’ve seen people claim this was a “cool summer” or a “terrible summer” on social media. That’s a ridiculous claim and not supported by facts.
In many areas west of the Cascades, this summer was WARMER than any summer before 1958. A better way to state this? In the 1930s-50s this would have been considered one of the the warmest summers on record! That shows how our summer climate has warmed over time. First image includes lowlands west of the Cascades between the Coast Range and Cascades. Second image is coastal areas. Data from NCEI.
Even though west of the Cascades it was in the top 1/3 of “warm summers”, this summer was COOLER than the past six. The coolest since 2012. That also tells you how crazy hot the past few summers have been. This is likely the reason many of you think it was a “cool summer”. But definitely not. In fact check out the 80 degree days in Portland; a bit above average so far
Warm nights were the rule this summer. Of course in the urban areas it’s hard to chart long-term climate trends for low temps since cities turn warmer as they grow. I covered that in a post earlier this summer. But even in rural areas there were plenty of warm nights. Part of it was due to cloud cover, some likely due to the return of a warm “blob” of water in the Eastern Pacific, and some due to a warm airmass in general. Here are the PDX numbers, of course heavily influenced by the urban heat island
It SEEMS like we had more partly cloudy or cloudy days right? Especially in early-mid July. I think that may be where the feeling of a “slow start to summer” began. That said, if we take all of June through August, we saw FEWER totally cloudy days than average. And a normal number of clear days. Anecdotally I would say that’s true. Many of our marine pushes off the Pacific Ocean were weak this entire warm season. Fewer thick morning cloud cover days but maybe more partly cloudy days in the afternoons? Just a guess.
No heatwaves! This was a strange one. We had two very hot days in early June, then two more at the end of August. Otherwise no extended periods of hot weather. Many times from late June onward the models tried to push a hot upper-level ridge in over us. But it only happened twice. It was continuously mild to warm but no long stretches of 90+ days. In fact as of today we’ve seen just 11 days at/above 90 degrees. That’s FAR less than recent years. That’s also a little below the 13-14 day average.
FIRE SEASON DOESN’T DELIVER (GOOD!)
Remember those dramatic predictions of “another smoky summer ahead” by some in media and elsewhere? I remember thinking at the time that it all depends on what happens DURING the summer, not leading up to summer (a dry late spring). Sure enough, we had occasional cooldowns and even some showers here and there to keep things in check. It shows you how important the heatwaves are (plus lightning) in getting the big fires started and growing. As of right now, this fire season is pretty much dead. Fuel moisture on the western side of the Mt. Hood National Forecast is at a record high for this time of year too. So far, less than 200,000 acres have burned in Oregon and Washington; the lowest number since at least 2010. I have a feeling that isn’t going to change much over the next three weeks.
Chief Meteorologist Mark Nelsen