We at the moment are experiencing probably the most sustained extension of summer season climate into autumn in a few years, with one of many signs being the longevity of some smoldering fires over the area.
And the smoke from these fires reveals some fascinating facets of native meteorology and the consequences of terrain.
Yesterday afternoon one might see smoke plumes from the Bolt Creek and Lake Wenatchee fires heading westward towards western Washington. Photo voltaic heating through the day reinvigorated the fires and helped combine the smoke vertically the place it was caught by the easterly (from the east) winds of the decrease environment.
NASA MODIS Imagery round 1 PM, Saturday
In a single day, because the floor and decrease environment cooled, vertical mixing was tremendously weakened and the cool air tended to maneuver down-valley in the direction of decrease elevation…on BOTH sides of the Cascades.
As an example, check out the seen satellite tv for pc picture round 8 AM this (Sunday) morning.
Smoke from the Bolt Creek fireplace was transferring westward down the Skykomish Valley into western Washington, whereas the Lake Wenatchee fireplace smoke adopted the Wenatchee River Valley eastward into Leavenworth and the Wenatchee space.
Each of those “valley smoke flows” unfold out as they gpt out of the mountains.
The smoke not solely undermines air high quality, but additionally impacts clouds. Look rigorously on the Snohomish River valley east of Seattle–can you see the fog there?
The PurpleAir air high quality observations clearly present the unlucky implications of the smoke (see beneath). The Bolt Creek smoke plume is exiting round Monroe after which swept southward over the jap suburbs of Seattle. MUCH higher air high quality close to the Sound.
The Wenatchee River smoke plume is related to very unhealthy air high quality from Lake Wenatchee by means of Leavenworth to the Columbia River.
Tomorrow (Monday) shall be related…sorry.
The Downside
The environment is caught. The atmospheric circulation has been locked into a really secure sample with a ridge of excessive stress over the West Coast and two troughs on each sides–called an Omega Sample.
Check out a collection of upper-level maps (500 hPa, about 18,000 ft) displaying heights above sea stage (you can even consider this because the stress at 18,000 ft). Purple colours point out ridging/excessive stress and blue/greens are the other.
This morning there’s a ridge over the western US and troughs on each side. An omega sample).
The state of affairs late Thursday is comparable with even larger amplitude. This implies dry and heat over the Northwest.
And the forecast for October twelfth is solely extraordinary. An omega sample on steroids.
We could not see a single drop of rain earlier than mid-month. Have we ever had a very dry first half of October?
Right here is the information for Seattle….the reply is sure… a number of occasions.
Surprisingly sufficient, this scorching, dry sample will forestall new wildfires over from western Washington and Oregon, in addition to California.
Atmospheric Sciences 101
Like final 12 months, I’m educating atmospheric sciences 101: a normal introduction to climate and local weather, this fall. You’ll be able to study extra concerning the class on the class web site. I speak about all the pieces from the fundamentals of the environment to climate prediction, thunderstorms, hurricanes, and native climate to world warming and local weather.
I shall be educating the category in particular person on the UW, however will even make it out there over zoom. Thus, of us can take it remotely.
In case you are over 60, you possibly can take the category by means of the ACCESS program for a really nominal cost (one thing like $15). Final 12 months I had over 125 of us achieve this.
So if you’re a UW scholar trying to study climate or a non-student within the subject, I welcome you to affix me this fall. My top quality is on September twenty ninth.
