As much as 3½ inches of rain is expected to fall in the Thurston County area in the next 48 hours, resulting in small-stream and urban flooding. Flood warnings are in effect for the Skookumchuck River near Bucoda, the Chehalis River near Grand Mound, the Deschutes River and the Nisqually River, according to the National Weather Service.
Two to 3½ inches of rain is expected to fall in the region before tapering off Monday, although the rainstorm is not expected to be as severe as in 2007 and 2008, when flooding devastated parts of Lewis County and South Thurston County and flooded a portion of Interstate 5. The last time 2½ inches of rain fell in the Olympia area was Nov. 6, 2008, meteorologist Johnny Burg said.
He said rain began falling in the Olympia area about 7:59 a.m. today, and the area had received about three-quarters of an inch of rain by the afternoon.
“Last winter was pretty tame; this winter is different,” he said.
This type of storm is sometimes referred to as a Pineapple Express, a weather front that pulls moisture from the tropics and is characterized by lots of rain and higher temperatures. Sunday’s high temperature is expected to reach 56 degrees, with overnight lows in the 45- to 49-degree range, Burg said. Snow levels also are expected to rise, which means rain likely will fall in the mountains and immediately wash off into rivers, contributing to potential flooding.
Snow melt will not be a factor, he said.
The outlook for South Sound rivers:
Skookumchuck: Moderate flood warning. Expected to rise above flood stage at 10 a.m. Sunday and crest at 15.8 feet at 4 a.m. Monday before falling before flood stage Monday evening.
Deschutes: Moderate flood warning. Expected to rise above flood stage at 2 a.m. Sunday and crest near 14 feet at 4 p.m. Sunday before falling below flood stage Monday morning.
Chehalis: Major flood warning. Expected to reach flood stage at 5 p.m. Sunday and crest near 18.1 feet at 10 a.m. Monday before falling before flood stage Tuesday afternoon.
Nisqually: Minor flood warning. Expected to rise above flood flow at noon Sunday and reach its crest at 4 p.m. Sunday before falling before flood flow Sunday evening.
Meanwhile, in Olympia, the city’s storm and wastewater utility department responded today to some calls from residents about urban flooding, said Gary Franks, operations supervisor.
The department received calls about plugged or blocked drains and culverts, as well as water forming at intersections.“It if keeps raining like this, we’ll call in half our crew,” he said about activity planned for Sunday. That could mean checking larger waterways in the city as well as Yauger Park, which is known to flood during heavy rainstorms.
Rolf Boone: 360-754-5403, firstname.lastname@example.org