I’ve written here occasionally about how the historically mild ocean-facing (west of the Cascades) Pacific Northwest climate is becoming more and more like its southern neighbor and sibling, the “original” hot-summer Mediterranean. Most recently I wrote in late July, during an exceptionally long heat wave. How does becoming “more genuinely Mediterranean” look like?
- The dry summer season becomes longer and longer, hotter and hotter, drier and drier.
- Heat waves that are not really “heat waves” anymore, just weeks-long stretches of dry hot days. As I wrote in July, they become the New Normal.
- More violent storms during the cooler wetter seasons.
We’re seeing all of this happen now, literally in front of our eyes. When we moved to Seattle (from very hot-summer Israel-Palestine) 20 years ago, effects of global heating were already visible — but still, both winters and summers tended to be mild. That didn’t last long. Precisely 10 years ago, right after the first zero-precipitation calendar month in recorded Seattle history, I decided I’d seen enough and wrote a diary compiling the various records broken during our 1st decade in Seattle. Ugh; in retrospect — and as climate modelers keep telling us — in 2012 I ain’t seen nothing yet. At that time the Pacific Northwest (PNW) was still expected to suffer relatively milder effects from global heating. That notion is now out the window.
In particular, getting choked by a wildfire smoke plume from somewhere in the greater PNW, with particulate matter rising to hazardous levels for days and weeks — wasn’t yet a regular annual Seattle summer occurrence in 2012.
But it is now. Every single year since 2017. Just Thursday evening during a walk through the neighborhood, I commented to Orna that we seem to have escaped smoke in summer 2022, despite it being very hot and dry (in historical PNW terms).
The very next morning the sun took on that dreadful orange hue, and I realized I had just jynxed us, big time. This had been in the cards for weeks; since August 11, two medium-size (in gigantic American West terms) twin wildfires were burning just east of the Cascades crest, 100km east-north-east of our home. As long as the winds blew in from the ocean — their usual direction — Seattle area remained clean. In fact, exactly a week ago we did a rare backpacking trip only 40km southwest of the fires, and didn’t get any smoke.
So that’s where Friday’s smoke came from. It became bad enough for our son to cancel his afternoon cross-country practice. But by evening a “marine layer” settled in, and things became reasonable again.
Saturday morning I wake up and it’s even worse and deteriorating. We shut all the windows, thinking it’s simply that the wind switched easterly again. It took our older son waking up and checking his feed (he’s a journalist), to inform us that there’s a raging, brand-new fire, west of the crest and literally in our back door. Only a few km from where we had camped last Saturday night! Within a few hours from its inception early Saturday morning, this new Bolt Creek fire grew to nearly twice the size of its month-old easterly neighbors. It was fueled by easterly winds and hot ~30c temperatures.
With this massive fire much closer and winds blowing its smoke onto us, the air has become far worse. Here’s the particulate air quality trace since Friday in our neighborhood, north of us in Everett (‘RambullAQS’)— and in the foothills town of Index right west to the fire. Index is now under “mandatory” evacuation; reportedly only half of residents there and further west right in the line of fire, have agreed to evacuate.
Note that the AQI scale is not proportional at all — in particular, at the higher end huge increases in particulates only add a few points to AQI. That last value at index translates to 191 micrograms per cubic meter — 50-60x the normal summer level. That’s AQI 241. Conversely, AQI of 100 is “only” 35 micrograms, which itself is nearly 3x the value at AQI 50 (12 micrograms/m3).
Just like we had camped there a week ago, this weekend too the area was full with people who had planned to enjoy the outdoors. Here’s a now-viral pic taken yesterday by hikers coming down right across from Baring Mountain.
Many PNW hikers (not us) are hardcore; for them a 4000-foot vertical scramble up peaks like Baring Mountain is a totally routine day hike. Two such dudes were unlucky to start precisely that hike early morning yesterday, before news of the fire came out. Then, they saw smoke but like us, had thought it was from the twin fires further east. By the time they realized they must come down, they were near the top and the fire had closed in on their path back down. Very fortunately, they have survived to tell the tale.
In legacy west-of-the-mountains PNW climate, this kind of fire rarely happens. The forest is just too moist. Even though summer is the dry season, during a historically-normal PNW summer there’s a substantial rain episode at least once every 1-2 weeks. By contrast, here’s how our precipitation has looked like in the past 2 months. Plotted are the official SeaTac airport gauge, and a pass right on the Cascades Crest, ~50km south of the fire. Note the vertical scale! In two months barely 5mm (0.2”) cumulative have fallen on the western Cascades and most of Western WA.
Since the west-of-the-crest forest is far richer, it grows way more fuel material than east-of-the-crest forests. When we hiked last week, right south of where the fire is now, we kept noting how dry everything was. Our footsteps were often raising dust clouds. Normally this is one of the lushest and rainiest parts of the region, home to magnificent Old-Growth trees (a small remnant of what was here before Western greed colonized the region, but still very awe inspiring). But despite some localized downpours we encountered on our drive back Sunday night, there were no widespread meaningful rains.
The lush mountain forests have become a literal tinderbox, which has unfortunately ignited on Saturday morning. Here’s one last graphic of the Bolt Creek fire, with many landmarks familiar to those who’ve hiked the area.
3:45 pm update -------------------------------
Thank you BOHICA in the comments, for pointing out the obvious: these aren’t the only PNW fires right now, and by far are also not the largest.
In particular, the Cedar Creek Fire, straddling the Cascades crest in south-central Oregon, seems to have tripled in size to 86k acres yesterday. It’s affecting all of Oregon’s major cities, including Portland 200km almost due north. See BOHICA’s comments below for some images.
Although Portland air might also be hit more by the even bigger, >150k acre Double Creek fire in far NE Oregon near the Idaho border. That one has joined, and quickly dwarfed, some longer-tenured fires in that general region.
Also (hat-tip to MarEng in the comments), the Bolt Creek fire has of course closed US-2 highway which runs right along its southern edge; the highway will hopefully help prevent the fire from jumping south into Alpine Lakes Wilderness. In addition, further south in Western WA the (smaller) Goat Rocks fire, also west of the crest and just south of Mt. Rainier National Park, has closed US-12. These are the #2 and #3 roads across the mountains in WA by traffic volume. Thus far the #1 highway I-90 seems to handle the traffic well — possibly because many people have cancelled weekend travel plans?