Late last night, I had the unfortunate mishap of wandering to another website WITHOUT first saving my blog-in-progress.  More than an hour of work was instantly lost.   I’m not going to make the same mistake again. But this blog will be shorter than originally planned.

The big story in our September weather picture has shifted from extreme heat, to extreme wind and fire danger.  Basically the cold airmass over the Rockies and Plains beginning tomorrow, is going to come a little closer to us than previously thought- close enough for moderately cool Canadian air to spill into the Columbia Basin.   This is remarkably similar to a wintertime pattern where arctic air just barely brushes by us, with all the frigid stuff remaining east of the divide.  Except that it’s September and the continent is about 40 degrees warmer. Here is the WRF-GFS pressure map for 3am Tuesday:

WHOA.  I’m pretty sure nothing quite like this has happened in early September in my lifetime. The pressure gradient between  North  Bend, OR and Spokane,  WA is about  24 mb northeasterly.  It honestly looks more like the gradients during a strong arctic blast.  Needless to say it’s going to be very windy AND very dry.  The absolute worst-case scenario for fire danger.

How unseasonable is this pattern?  Some NWS meteorologists have been saying that this kind of pattern happens less than once every 30 years, during the late Aug-mid Sep period.  We did have a pretty significant ‘Virgo Windstorm’ during September 2014, also caused by slippage from a cold airmass to our east.  But that storm was weaker with respect to pressures, as was the east wind during the devastating Eagle Creek Fire three years ago.

And how windy?  I don’t have access to really good wind maps, but here is a version of the ECMWF for 10pm Monday night:

The strongest gusts will be in the Cascade passes, west foothills, and Coast Range where they are expected to range from 50-75 mph!  Also some 40-50 gusts in the Portland area. That’s plenty for some downed trees and outages.  However, some of the power outages tomorrow and Tuesday may be intentional; done by the power company to prevent the risk of electrical fires.

Speaking of fire….this is a DANGEROUS pattern. Like California dangerous, or for that matter the Yacolt or Tillamook Burn.  Both are also believed to have been caused by early fall cool air to the east triggering a dry windstorm in our area.  We’re at the peak of our dry season. Now you add strong and desiccating winds with relative humidity in the teens…and voila.  Red Flag Warnings are up for the entire northwest quadrant of the state, Monday evening through Wednesday.

In addition to not lighting any fires, be careful about where you park outside. The hot underbelly of an automobile can easily ignite flammable grass and brush.  Also….lawn mowers and weed whackers and chain saws are not smart either.  Just be very, very mindful of the landscape; in this pattern it is a powder keg ready to explode at any moment.

The wind dies down late Wednesday and we have at least a couple more hot days beyond that. In general we’re going to stay mostly dry and warm as we inch toward mid-September.

Be safe and wise these next few days! -Karl