Tacoma was on the lookout for rare tornadoes Thursday.
No twisters ever came, but the storm front the National Weather Service thought might cause one did flood streets by overwhelming storm drains in parts of the city after spurts of thunderstorms dumped rain through the evening.
“We don’t get very many (tornadoes), they’re going to be rare,” Weather Service meteorologist Jay Albrecht said. “If we get them, they tend to be pretty small and weak, but that doesn’t mean you won’t get damage from them.”
Tornadoes have hit the region in recent years. One knocked down trees and cut power in Enumclaw in 2009, and a funnel cloud touched down in Commencement Bay in 2003.
Rotation in the storm cells had meteorologists keeping an eye out for funnel clouds Thursday, which become tornadoes when they touch the ground, Albrecht said.
“We’re seeing some pretty heavy rainfall for brief periods as these cells move over,” Albrecht said.
It was hard to measure how much rain the short bursts brought unless they happened over weather stations, Albrecht said. That happened in Olympia, where 0.9 inches of rain was measured in a 20-minute period.
“The one that hit Tacoma was one of the heavier ones,” Albrecht said about 5 p.m., when the storms appeared to have headed north to Renton. He thought others might form over Lewis County and could follow.
The storms were supposed to clear up overnight, and things were expected to be nicer Friday. A high of 74 was forecast, according to data from Joint Base Lewis-McChord, and Saturday was expected to be sunny with a high of 80.
But Thursday afternoon was anything but sunny. Heavy rain kept crews busy as they responded to flooding reports, said John O’Loughlin, assistant director of environmental services for the city.
Debris-clogged drains and small drain pipes in the storm water system affected some backups, though in many cases Thursday water had drained away before crews arrive.
“It’s not designed to make sure that there’s never any flooding ever,” he said.
He didn’t know of any lasting flooding from the storm, but said two manhole covers did pop off on Pacific Avenue that had to be put back in place.
Crisstoffel Jackson said half of the sidewalk outside his Hilltop home flooded, but that he convinced his daughter they should go to the Tacoma Rainiers game anyway.
“It stopped raining as soon as we pulled up,” he said about 8 p.m. “It’s gonna be a perfect day for baseball.”
Another brief deluge came down on the city about an hour later.
Alexis Krell: 253-597-8268