The week of July 22, 2024, will see wildfire smoke spread across the US affecting visibility and air quality in many US states and Canada. The wildfires causing this smoke transport are primarily located in Canada with additional wildfires in the Pacific Northwest that could increase the smoke transport late this week.

Let's look at the current wildfire/smoke conditions, and the smoke forecast this week.

Current Wildfire Conditions

The US and Canada wildfire season is in full swing with a growing number of wildfires in the past couple of weeks. In Canada, as of July 21, 2024, 3,434 active wildfires have burned 2.1 million hectares. There are currently 871 active wildfires primarily located in British Columbia, Alberta, and Saskatchewan. 

In the US, as of July 18, 2024, 66 large active wildfires have burned 1.1 million acres. The wildfires are primarily located in the Pacific Northwest (PNW) with a significant wildfire in southern California as well.

Learn More → Northwest Wildfire Maps & Updates Mid-July 2024

The largest of these wildfires are in the PNW, with a combination of human and natural (dry thunderstorms) causes of the wildfires. There are other wildfires in western US states, but these are smaller with fewer effects.

Current Smoke Conditions

The wildfires in the US and Canada are producing smoke that is affecting visibility and air quality for millions of people. The wildfires occurring in Canada are pushing smoke to the south, affecting areas east of the Rocky Mountains in southern Canada and the central US. The most dense smoke is closest to the CA-US border but the smoke is extending all the way to Texas!

Check out the OpenSnow smoke map across southern Canada and the US on Monday, July 22.

The US wildfires in the PNW are causing smoke to stay relatively local with a semi-stationary high-pressure system causing smoke within Washington, Oregon, Idaho, and Montana. The other wildfires in the western US are smaller with less smoke transport. The exception to this is the Trout fire in southern California, as seen at the bottom of the satellite loop below on Monday, July 22.

The fuzzy grey areas are wildfire smoke and the brighter white areas are clouds.

The wildfire smoke in the PNW is reaching the surface in many areas due to a stubborn high-pressure system that is keeping the airmass stable and limiting the mixing of the smoke to higher parts of the atmosphere. The high-pressure system has caused record heat over the past two weeks and also kept smoke at the surface, creating poor air quality in many areas.

Check out the OpenSnow air quality map on Monday, July 22. 

In the Midwest, Canadian wildfire smoke is causing poor air quality. The northern Great Plains are experiencing the worst air quality due to wildfire smoke mixing to the surface. Further south into Iowa, Nebraska, and Kansas, wildfire smoke is primarily affecting visibility with smoke higher in the atmosphere.

Putting this all together with the weather pattern shows how winds in the middle parts of the atmosphere (8,000 - 12,000 feet) are pushing wildfire smoke from Canada into the central US. Weak winds in the PNW are limiting smoke transport and confining the smoke to the PNW.

Smoke Forecast Week of July 22, 2024

A very similar weather pattern as above will continue for the first half of the July 22 week. A high-pressure system will remain stationary in the western US and cause smoke to remain semi-stationary. The northerly winds from Canada will continue to push smoke into the central US and even extend through parts of the eastern US. Most of this smoke will stay in the higher parts of the atmosphere, with localized areas (mainly near the CA-US border) seeing smoke and poor air quality at the surface. 

On Wednesday, July 24 changes will be coming to the PNW. A storm system will move into British Columbia (see above for the circular black lines and brighter colors) and slowly move the high-pressure system. This storm will have light precipitation associated with it that will mainly be confined to Canada with a few showers through the higher terrain in the PNW.

This storm will bring a slightly cooler air mass into the PNW and cause stronger winds, which will blow from the west to the east. Despite a slightly cooler air mass, this storm will increase wind speeds in the PNW, which could lead to more smoke transport. This will keep coastal areas in the PNW clear of smoke but push wildfire smoke from the Cascades and other areas into other western US states.

Additionally, increased wind speeds could lead to more dangerous wildfire conditions. Temperatures will still be in the 80s and 90s throughout the western US and very little precipitation is expected to fall. This combination will cause favorable fire weather conditions for the existing wildfires to grow and transport more smoke.

Below is a look at the mid-level winds (8,000 - 12,000 feet) forecast on Wednesday, July 24.

This storm affecting the western US will also affect the central and eastern US. It will cause less wildfire smoke transport from Canada because winds will shift from the north to the west. However, this could cause additional smoke transport from wildfires in the PNW to other parts of the US. The smoke transport will be most favorable through the northern half of the western US and the northern Great Plains. There is also a chance that smoke transport will reach eastern Canada and northern New England.

It is difficult to know how much the wildfires could grow and how this could affect smoke transport on Thursday, July 25, and thereafter. There will most likely be less smoke initially on Thursday and Friday, July 26, but there could be increased chances of smoke transport into the weekend on Saturday, July 27.

Below is a look at the mid-level winds (8,000 - 12,000 feet) forecast on Saturday, July 27.

The forecast becomes more uncertain into the July 27 weekend regarding smoke transport and wildfire growth. The above model favors smoke transport from the PNW into the upper Great Plains and southern Canada. Some smoke could dip down into northern New England as well with favorable conditions for more smoke transport in the US and Canada next week on Monday, July 29.

Make sure to keep a tab on the OpenSnow smoke and air quality maps to see the latest weather conditions.

Learn More → Air Quality & Wildfire Smoke Forecast Maps

Thanks for reading.

Zach Butler