March 14, 2011 in City, Idaho
Healthy snow pack to swell Inland NW rivers
The National Weather Service in Spokane today said they foresee an average chance that streams and rivers will reach flood stage this spring as a result of a larger-than-normal snow pack.
Most of the region’s rivers are likely to swell to full bank, and some may flood depending on the amount of rain and snow that falls in coming weeks.
Smaller streams in Eastern Washington, including Latah Creek, Little Spokane River and Palouse River may see higher flows by later this week.
Milder air and a series of storms are causing those rivers to fill to near capacity, said forecaster Jeremy Wolf on Monday. Lower elevation snow pack has been melting.
Wolf said the weather service is advising residents to prepare for potential stream rises and use caution when approaching rivers and creeks.
“Rivers are expected to respond to the wet conditions over the next several days, but flooding is not expected,” according to a weather service outlook issued on Monday by hydrologist Katherine Rowden.
A La Nina weather pattern got the snow pack to build during November and the recent series of late winter storms has also contributed to healthy snow packs.
As spring progresses and snow begins to melt, several Inland Northwest rivers are likely to approach flood stage, including the Coeur d’Alene River at Cataldo where it may rise to within a foot of flood stage.
The St. Joe River at St. Maries should rise to less than a foot above flood stage.
Similarly, Pend Oreille Lake should rise to a foot below flood stage later in the spring. The Kettle River near Ferry, Wash., also is at risk of reaching flood stage.
The water equivalent in snow packs across the region is running at 101 percent of normal on the Spokane River; 114 percent of normal on the upper and lower Clark Fork; 115 percent of normal on the Kootenai River; 93 percent of normal on the Salmon River; and 103 percent on the lower Snake River drainage.
The east slopes of the Cascades has snow pack amounts that are below normal, and that may limit irrigation water in places such as Yakima Valley, hydrologists said.
The lower Columbia Basin is also considered abnormally dry in the latest U.S. Drought Monitor, Rowden said.