Dangerous Fire Weather Likely in Western Washington

By Monday, dangerous fire weather conditions will set up in Western Washington. Winds gusting 30-40 mph, along with humidity of 10-20% will bring very dry conditions that will accelerate fire spread. Conditions will remain like this through Tuesday night.

Below is my video update of the current weather situation along with the sunset in the background!

Upper-air smoke tonight (from California fires) made for a beautiful sunset! Here's a photo I captured from my yard!

If you noticed that skies on Friday weren't as blue and they normally are, and that there was a reddish tint to the sun, that's because of smoke aloft (high up in the atmosphere).

A marine push overnight will bring cooler temperatures and clouds for Saturday. Some fog, along with possible low-level smoke could also be around Saturday morning. It will clear by the end of the day and highs will reach 70 degrees. Sunday will be another clear day, with highs reaching 80 degrees.

However, as Sunday goes on, winds will begin to shift offshore.

By Monday morning, winds will have shifted to support strong offshore flow (wind blowing from Eastern WA towards the coast). These winds will strengthen due to a pressure difference across the Cascades. 

Gusts in the South Sound will reach 30-40 mph on Monday and Tuesday. Here is the forecast from the ECMWF model for Puyallup.

Notice that winds in Puyallup gust 30-35 mph on Monday and Tuesday. These winds are being pushed through the Cascades, and areas from Kent to Graham and in the foothills are "favored" to receive stronger wind gusts (30-40 mph in this case) than other areas in Puget Sound, due to their location relative to the gaps in the mountains. Power outages are possible, but not highly likely, on Monday and Tuesday with these winds.

In addition to this, there is a chance that low-level smoke will be pushed into Western WA due to the shift in winds. This hasn't been verified yet, but I'd be prepared for bad air quality and hazy skies.

Another aspect of this fire weather setup will be exceptionally low humidity values. Below is the forecast humidity on Monday afternoon.

These are exceptionally low values. We consider it a "dry" day when humidity reaches 30%, but these forecasts indicate values of 10-20% on Monday and Tuesday afternoons. This will help to spread fires rapidly. Humidity around 10% is typical in Phoenix...shows how dry we will get.

To show just how dangerous these fire weather conditions will be, here is the Hot-Dry-Windy index for Monday. This index shows the probability of explosive fire growth.

Nearly all of Washington has a very high index value, indicating conditions that allow fires to start and grow very easily. 

All these conditions that help fires grow rapidly remind us of the need to stay safe and avoid burning, especially when it is windy & dry.

Finally, and probably most importantly, a Fire Weather Watch is in effect from Monday morning to Wednesday night. You can find the alert by clicking HERE, and it is shown below.

There's a couple things to pay attention to. Winds will gust 30-40 mph out of the east, and humidity will be 10-20%. It is likely that this will be upgraded to a Red Flag Warning in the next couple days.

Keeping with the theme of hot & dry weather, temperatures of 85-95 degrees are likely from Monday through Friday, with the hottest days (widespread highs 90+) being Wednesday and Thursday. 

Update on the Evans Canyon Fire in Eastern WA: 

The fire has burned over 70,000 acres and is one of the 25 largest fires in state history. Firefighters are trying their best to contain this fire, but it is only 10% contained. Below is a map of the fire showing its approximate boundary. (Note: not all areas outlined have been burned).

Please keep those impacted by this fire and those fighting it in your prayers. Conditions will continue to be very favorable for explosive growth.

Stay tuned as this dangerous fire weather setup continues. I will have updates soon.