Grass and Range Fires East of the Cascades

As expected, the massive lightning event this week led to the ignition of several wildfires.

But our region lucked out:  few fires were started on the eastern slopes of the Cascades within forested areas.  

This is because we are in the early season, which means less time for drying in the slow-to-dry forested areas, and because of the distribution of lightning (relatively little lightning on the eastern slopes).

Below is a map of the largest fires.  

Most were in grass and range vegetation, with the greatest fire activity in southeast Washington and northeast Oregon, where the most lightning occurred.

You can see the smoke in the midday high-resolution visible satellite image (as well as low marine clouds over western Washington).

Some satellites can observe the heat from the fires....and here is the same image with fire locations (orange dots).

The grass/rangeland of northeast Oregon is clearly the "hot spot" for the fires.

It is important to note that such fires have little to do with global warming or heat waves. 

 Light fuels, such as grass and range vegetation, are typically dried by now, and lightning events like this week have no correlation with a warming planet.

Want proof that the moisture level of the fuels (grass/range vegetation) was not unusual?

 Below is the data from the US Forest Service showing you the 100-hour fuel moisture levels. (100-hour fuels include dead organic materials, such as branches and dead roundwood, that measure between 1 and 3 inches in diameter.) The observed moisture levels (red line) are in the middle of the average range (gray shading).

But something has changed over the past decades the was made our grass/rangelends far more flammable...the invasion of explosive-burning cheatgrass and other fire-friendly species.

This map shows you the extent of the problem and why eastern Washington and Oregon are so vulnerable

Flammable grasses have taken over the region (see below), and ignition by lightning or human activities can start a firestorm.

And there is one more thing.  

To get large fire growth requires strong winds, and the weather systems that produced the thunderstorms also provided large wind gusts, both during the storms and after.   

Want proof?  Check out the maximum winds on Thursday (below).

Winds are declining now, and you can expect that the grass/range fires will quickly decline.

Massive Lightning Outbreak Hits The Northwest

One of the greatest Northwest lightning outbreaks in recent memory occurred today, with well over 5000 lightning strokes over the region.

Below are the strokes over the past 24 h:  very impressive.  

There were three major thunderstorm paths...one down the lowlands of western Washington, one along the coast, and a broad band in eastern Oregon and Washington.

Importantly, there were very few lightning strikes on the eastern side of the Cascades, which greatly reduced the chances of forecast fires there.

The massive lightning activity over northeast Oregon did start fires.

Normally, the Pacific Northwest is the poor stepchild of lightning activity in the U.S.  But look at the national lightning activity for the past 48 hr below.  For once, we were in the league of Florida or Texas!

The radar image this morning was enough to promote goosebumps for the meteorologically inclined:

And today's precipitation totals were quite significant, with several locations receiving over a half-inch (see today's totals below).

The visible satellite image  around 10 AM looked like something out of Oklahoma:

During the morning, several folks told me they saw funnel clouds, based on pictures like this:

I saw such clouds myself... which result from aircraft passing through a low cloud deck. NOT a tornado.

Let me end with a truly remarkable image.

Low clouds were left in the wake of the thunderstorms over western Washington, but Mount Rainier extended above the clouds. Eastern Washington is now experiencing plumes of smoke from fires ignited by the lightning over northeast Oregon. The green areas show lightning strikes.