Smoke and Fire During A Cold Wave

One of the most interesting aspects of the current smoke/fire event is that it is occurring during a cold wave.

Over the past few days, temperatures in eastern Washington have been well below normal.   

Not a heat wave associated with global warming.  A cold wave with strong winds.

Don't believe me?  Below are the daily low surface temperatures yesterday and today (only showing values of 40F and below).

My God! 

Several locations dropped into the mid-30s!  Since such temperatures are measured around 6 feet, the surface temperatures could have dropped to freezing!

Smoke and ice...what a combination.

The surface temperature analysis for Sunday at 4 PM shows the very cold temperatures over the northwest.  Burr.....

Temperatures aloft were also very cold.  

Here are plots of Sunday and Monday morning temperatures around 5000 ft (850 hPa pressure).  Blue is colder than normal.

The cold and winds (which produced the rapid fire growth) are connected, both associated with a strong upper-level trough of low pressure moving through this weekend (see map at 500 hPa, about 18,000 ft below).  

Blue shows heights below normal (a trough).

Currently, air quality is good in western Washington, with any smoke staying aloft, moderate in the Willamette Valley, and poor in eastern Washington (see below).

The forecast surface smoke (NOAA HRRR Smoke model) for 11 PM tonight is good for western Washington, unchanged for the rest of the region.  Really bad near the Little Giant Fire near Lake Chelan.

Strong Winds Cause Major Expansion of Eastern Washington Wildfires

As feared, the great enhancement of cool, westerly winds caused a large increase in eastern Washington wildfires, with the Little Giant Fire expanding to Lake Chelan.

The change in visible satellite imagery yesterday shows the major changes

Early in the day Saturday, you can see the smoke from a few fires in eastern Washington, with the Little Giant Fire possessing only a modest amount of smoke.  Lots of low clouds in western Washington.

But later in the afternoon, as strong winds surged into eastern Washington, the fires exploded, with massive smoke plumes.

Here is a close-up at the same time.

The satellite image this morning shows a massive smoke cloud from the Little Giant fire extending into Montana and beyond.

Satellite sensors can pick up the emission from fires, and this morning's image of the Little Giant fire indicates a rapid spread of flames to the east, with some fire reaching Lake Chelan.

As noted earlier, this major fire blowup was associated with strong winds resulting from the movement of cooler, onshore flow into the region.  Cooler air associated with a Pacific weather system.

Below are the maximum winds over the region on Saturday.   At several locations,  wind reached 40-50 mph.

Zooming in to the area of the Little Giant fire, multiple locations surged to around 50 mph.

The strong winds were accompanied by profound cooling, something shown by the 24-hour temperature change (ending 6 AM this morning).  

Many locations were 20F cooler!  

The strong winds also resulted in some fire expansion near Spokane, which was picked up by weather radar yesterday:

The winds will calm down today, and the fire growth should greatly decline.   

In any case, this event illustrated the profound danger of lightning, dry fuels, and wind.  Often our big fires are associated with cooling weather, not heat waves.

But one thing has profoundly changed.   Our ability to PREDICT the winds is immensely better than 20 years ago, allowing far more effective preparation and protection for such events.

The question is whether society will properly take advantage of this forecasting prowess, including de-energizing powerlines.