‘Atmospheric river’ bringing heavy rainfall, increasing threat of urban flooding, mudslides

An atmospheric river is bringing significant rainfall to Western Washington through Friday morning.

The warm front is slowly moving south Thursday afternoon. It has been heaviest north of Seattle, but is increasing over Olympia, Tacoma and Seattle. The trend will continue Thursday afternoon, and the rain

It will stay heavy until early Friday morning when the rain tapers off. Highs will be in the low-60s.

Rainfall totals will range around 1 to 2 inches for the lowlands, around 3 to 6+ inches for the North Cascades and the Olympics, and around 2 to 4 inches for the coast.

Some area Flood Warnings are expected for rivers feeding off the mountains to the north. Pockets of urban flooding are also expected due to clogged storm drains.

Besides the river flooding potential and the breezy conditions…a lot of us will deal with localized ponding and pockets of urban flooding. Clear those storm drains! #NickKnows #wawx https://t.co/pmNwcT9NLE

— Nick Allard (@NickAllardKIRO7) October 28, 2021

The National Weather Service said the rainfall rates will increase the threat for landslides.

Crews are preparing for flooding and falling trees. Arborists said the drought during the summer laid the groundwork for problems this fall. Trees can’t handle the weight of constant precipitation, especially after the soil was soaked from last weekend’s storm.

Arborists are expecting high call volumes over the next few days.

Overall, it’s going to be a very wet day with breezy conditions and some possible flooding concerns.

StormTracker Doppler Radar Livestream

WEEKEND OUTLOOK

Friday morning, the rain will end fairly quickly, with just a few lingering showers past the morning. We should see increasing sun Friday and through the weekend. Halloween looks fantastic with highs in the mid-50s.

>>KIRO PinPoint 7-Day Forecast

There’s a chance for a few showers on Monday night into Tuesday, with more rain by Wednesday.