Quick Thursday Evening Fire Weather Update

10pm Thursday…

It’s been another extremely busy day for fire crews over and west of the Cascades. These last two days have seen an unprecedented number of large fires west of the Cascade crest.

There is one bit of bad news, but much more good than bad weatherwise this evening.

First, evacuation zones have been expanded in Clackamas County; Level 3 (GO NOW) includes Marquam, Estacada, Colton, & Molalla. Even Oregon City, Canby, & Sandy are in a Level 2 (BE READY) zone now. You can find this map on the Clackamas County page Click for a better view…


ABSOLUTELY NOT AT THIS TIME! Authorities are being very careful and proactive. They are making sure people are not in danger in these towns. An “abundance of caution” might be the best phrasing here.

But there is very good news for evacuees weatherwise…the dry east wind is gone! The most dangerous “explosive fire growth” phase of this event has ended. As a state official said at a news conference earlier today, he felt today was the day “we’re turning the corner”. That’s good news.

At this moment wind is either calm or almost calm everywhere west of the Cascades. I can’t find a wind gust over 15 mph inland from the coastline! That includes the Cascade foothills as well. And that wind is coming from a westerly direction = more moisture from the Pacific Ocean. A fire sure won’t be racing westward out of the mountains and down into the lowlands in these conditions. Check out relative humidity, way up from the teens and 20s yesterday at this time in the valleys.

The two coastal fires are now under the influence of a chilly & humid marine airmass. They are done making any advance towards the beach towns (Lincoln City).

Where do we head from here? A brief summary…

We now enter a more “normal” forest fire situation in the mountains and foothills. Each afternoon through Sunday a westerly breeze develops, but this will push those fires mainly eastward, farther into the mountains. So if a town hasn’t burned yet, it seems very unlikely it will from this point forward. But fires WILL continue to grow; these are massive fires!

To summarize…in the lowlands of Northwest Oregon.

  1. There’s no reason to believe any of the large fires will suddenly advance farther down into lower elevations (westward) and into more towns/cities.
  2. Thick smoke will be with us through Saturday, possibly Sunday as well. Air quality is hazardous in much of the metro area right now, and down into the Willamette Valley.

Now that things are settling down a bit we can take a look at the acreage…the numbers are stunning. Here are the “mega fires” burning in and along the west slopes of the Cascades. Click for a closer view on each one

The 900 square miles of public/private forestland burned hits relatively close to home. I grew up in this area and know how important timber is for these towns. My wife grew up in Sweet Home with relatives in Mill City, Gates, & Blue River. Remember that private timberlands support families and communities too, not just national forests. For some people their future income just burned up, along with a home and/or town.

That’s it for now. I’ll be on tonight at 10/11pm and the evening shows again tomorrow.

Chief Meteorologist Mark Nelsen

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