Canada’s smoke, created by fires in the boreal forests of the sub-Arctic, is now above us.
You can tell this by the slightly opalescent shade of the sky or by looking at the satellite images visible this morning (see below).
The Puget Sound Clean Air Agency (PSCAA) has a device (a space meter) that measures smoke overhead. The mid-afternoon image clearly shows the densest layer of smoke at about 3000 – 4000 meters above the surface, less smoke below (time increases to the right)
Air quality across the area was good (green) to moderate (yellow) this afternoon, so I suspect that some people are experiencing poor air quality issues at this time. This. The situation is only going to get worse tonight when the big fireworks displays start to take place and people go wild with the show at their homes.
Temperatures rise from mid to above 80 degrees in western Washington and only slightly warmer over the Columbia Basin. Winds are relatively light in the Columbia Gorge, which is useful for containing the Tunnel Fire.
Tomorrow and Thursday will be similar to today, but then temperatures will start to drop on Friday. And circulation changes with cooling that will push Canadian smoke eastward.
The key change is the transition from having a higher high pressure over the eastern Pacific toToday (see chart below) for a depression over the northeastern Pacific something illustrated by the forecast map for Sunday at 8pm (second map)
The shift is predicted to bring rainfall back to the region and British Columbia in particular. The forecasted cumulative rainfall through Tuesday is shown below. Fairly heavy rainfall is predicted in the south BC. This is great news for residents of the Northwest as it will both reduce the threat of wildfires over BC (and we can feel some of their smoke) and bring water into the Columbia River.
At this point, it looks like the region will enjoy a week of near-perfect weather starting Friday, with highs in the 70s west of Washington, no Canadian smoke and no thunder. Lightning or strong winds can cause forest fires. Probably the best weather in the country.
