Portlanders have been counting down the hours until a predicted Monday night rain would diminish the smoke that's enveloping the city.

Well, hate to be the bearer of even more bad news, but it doesn't look like that's going to happen.

The weather system that was previously forecasted to bring rain—and better air quality—to Portland tonight and tomorrow will mostly hit the coast. At most, the Willamette Valley will receive a light sprinkling.

It's now likely that the smoke caused by the surrounding wildfires won't thin until Thursday, when more rain and westerly winds are predicted.

But according to the Portland office of the National Weather Service, it might be best not to get your hopes up even then.

"Don't be surprised if things get put off even further," says meteorologist Miles Higa.

What's more, there's a chance of thunderstorms later in the week, though the probability is low, Higa says.

Portland's air quality has been in the "hazardous" range of the Air Quality Index since Saturday. Other parts of Oregon are experiencing air quality so thick with particulate matter it's beyond the AQI scale—a serious health concern.

The Department of Environmental Quality's air quality advisory has been extended to Thursday for all of Oregon. Portlanders are encouraged to stay inside with doors and windows closed.

Multnomah County has opened additional emergency shelters, and those looking for shelter for themselves or their neighbors can call 211 to check availability and arrange transportation.