Low-pressure system this weekend may provide relief to fire-stricken areas

Wildfire smoke and warm daytime temperatures are expected to dominate the weather for the next two days, but big changes are possible starting on Friday night and lasting into next week.

National Weather Service forecasters said that a shift to a southwest wind in the lowest 5,000 feet of the atmosphere today may begin to lessen smoke problems.

Highs in Spokane should be in the middle 80s to around 90 today and middle 80s on Friday.

A low-pressure system that’s been stalled off the Pacific coast is expected to move inland late Friday and Saturday.

It is gathering remnant moisture from a tropical storm that brought a deluge to Hawaii earlier this week.

That rain should arrive across the fire-plagued areas of the northern Cascades and western Okanogan region on Friday afternoon and evening.

Rainfall amounts could reach an inch or more in the northern Cascades and lesser amounts as the storm progresses to areas to the east in Okanogan, Ferry and Stevens counties. North Idaho’s mountains may see some of that precipitation with the higher amounts falling to the north.

Forecasters said amounts could range from a tenth to 0.4 inches of rain in those areas.

The rain may persist for a 24-hour period over some locales, which will dampen wildfires more efficiently than a quick wet thunderstorm, forecasters said.

Lightning is not expected with the weekend storm. But it should bring relief from smoky skies by providing strong southwest winds, putting the urban areas on the upstream side of the largest smoke plumes.

Those winds will peak on Saturday when Spokane could see sustained southwest winds at 23 mph and gusts to 38 mph with stronger winds in the Columbia Basin. Blowing dust is possible.

Spokane should see rain shower chances increase on Friday night and Saturday, but linger through at least Tuesday. Amounts, if any, will be light.

High temperatures will drop back to the 70s with lows remaining in the 50s to near 60.