One More Day of Smoke, Then Clouds & Rain Arrive

Wednesday was a relatively smoke-free day in Western Washington, but that won't last for long. Major fires in Northern California are sending large plumes of smoke north into Oregon and Washington. 

These NorCal fires, particularly the rapidly growing Dixie, McFarland, and Monument Fires have completely destroyed towns, are showing extreme fire behavior, and have no signs of stopping. Western Washington residents should be thankful that we’re only experiencing smoke aloft. 

Below is the HRRR Smoke forecast for 7 AM Thursday. Potentially the heaviest concentrations of smoke aloft yet are moving north into Western Washington.

The good news is that virtually none of this smoke will reach the ground, and it won’t last for too long.

Below is 3 PM Thursday. The smoke plume has made it a bit further north up the Sound, but this is about as far north as it’ll go. Dense smoke is overhead across most of the state, except the northwest sections.

Heavy smoke aloft will likely stick around through nightfall, but overnight, a big change will take place, and when we wake up…boom! The smoke is completely gone! (7 AM Friday below).

Why? A weak weather system and stronger marine influence will push the smoke eastward and bring in marine clouds and rain showers. This marks a shift to more dominant westerly winds, which will keep smoke out of our skies for now!

Additionally, cooler weather, clouds, and rain showers are ahead! After a hot day on Wednesday (mid 80s to low 90s), temperatures will cool to low-mid 80s on Thursday, then to the upper 60s to mid 70s from Friday to Monday. Below is the UW rain forecast ending 5 PM Saturday.

Expect the Puget Sound area to get 0.05 to 0.2 inches of rain, with more on the coast and north of Everett (up to 0.5-0.75”). The Cascades will receive up to 1 inch of rain, good for minimizing wildfire risk (for now). The official dry streak will likely end in the neighborhood of 52 days, just 3 days short of the tying the all time record!

Speaking of wildfire risk, on Tuesday afternoon & evening, high instability and monsoonal moisture contributed to strong thunderstorms over the Cascades, east slopes of the Olympics, and parts of the Eastern Lowlands.

A total of 1,399 lightning strikes were recorded over Washington State. Of particular concern is the massive amount of strikes over the Northern & Central Cascades. The Northwest Interagency Coordination Center (NWCC) map and data shows where the strikes were.

While there was some rain with the thunderstorms, wildfire starts are still likely due to the massive amount of lightning strikes.

CAPE (Convective Available Potential Energy) instability levels were observed at 1,500 to 3,000 over the Cascades, levels comparable to other parts of the country with many more thunderstorms. Additionally, cloud tops reached 40,000-49,000 feet (radar estimated), which is high even by Midwest standards!

One thunderstorm, between Snoqualmie and Stevens Passes, was strong enough for NWS Seattle to issue a rare Severe Thunderstorm Warning for hail up to 1.75 inches (about golf ball size, radar estimated). In the RadarScope image below, the severe cell is outlined in the yellow warning polygon.

This storm cell was quite strong for Washington, and such Severe Thunderstorm Warnings and massive hail are rare for our state.

We’ll end with the extended forecast. As the rain & clouds move out by next Tuesday, expect a warmup and a return to hot and dry weather. The Weather Underground forecast for Federal Way is below.

Temperatures in the upper 80s to low 90s are forecast starting next Wednesday. Stay tuned.

For now, enjoy the upcoming clouds & rain showers!