Why West Coast Fires Are Producing Smoke & Bad Air On The East Coast

Via Cliff Mass Weather blog,

A remarkable situation is evident right now.   

Fires over the western U.S. are producing a dense veil of smoke that moved across the continent and then descended over the East Coast.

And there is a great irony in all this: most of the West Coast has excellent air quality while the air is unhealthy over the northeast U.S.

To illustrate this strange situation, here is the latest AIRNOW air quality map showing the air quality based on PM2.5, small particles that can move deep into your lungs.  ( I want to acknowledge UW Bothell professor Dan Jaffe, who brought this to my attention)

Green is good air quality while red is unhealthy. 

Really bad air quality in parts of New York, New Jersey, and Pennsylvania.  But air quality is really good along the West Coast!

You can visualize the movement of smoke by an image showing the smoke distribution at 11 AM this morning from the wonderful NOAA HRRR model.  Smoke generated over eastern Oregon, northern CA, and eastern WA moved northward around a ridge of high pressure centered over the Rockies and then headed southeastward towards the northeast U.S.

The smoke was quite apparent over the Northeast in the visible satellite imagery mid-day today (see below).  The grayish stuff is smoke.

The air reaching the East Coast has an interesting three-dimensional trajectory (the path of air in 3D space).  Using the NOAA Hysplit software, I found the origin of the air ending over New Jersey at 11 AM PDT today at 500 meters, 1500 meters, and 2500 meters above the surface ( see below).

Wow..the air reaching near the surface in New Jersey started over Washington State (red line).  First, the smoky air rose over the Northwest, gained altitude to catch stronger winds aloft, and then got mixed down to the surface over the East Coast.  A Washington import that may not be as popular as wine, apples, or cherries.

Kind of wacky, really….. start a fire here in the Northwest and the folks in the NY Metro area are choking in the smoke.

This kind of transcontinental smoke has happened before, but this event is particularly dramatic in terms of the air quality degradation along the East Coast.