In response to heavy rain, warmer temperatures and a melting snow pack, NOAA issued a Flood Warning for the Snoqualmie River near Snoqualmie Falls and Carnation. Moderate flooding will happen tomorrow, February 22nd. 
The flooding not expected to be anything like Snoqualmie experienced in January 2009. Near Snoqualmie Falls, the river is expected to crest Wednesday morning at about 35,000 CFS. At 30,000 CFS the Snoqualmie River causes widespread flooding of pasture lands from Snoqualmie downstream to Fall City. Low-lying roads in the Fall City, Carnation area may also be covered by water. This river level corresponds with a phase 3 flood in the King County Flood System.
Near Carnation, moderate flooding is also expected. The Snoqualmie River will crest near 58 ft. late Wednesday afternoon. Flood stage is 54 ft. At 56 ft. the Snoqualmie River causes widespread flooding from Fall City downstream to Carnation and Duvall, inundating local farmland and many roads.
The rain is expected to taper off tomorrow. Colder weather returns by Thursday to help alleviated the snow pack melt, putting less pressure on mountain-fed rivers. You can check local weather forecasts here.
Comments
Thanks for putting out the word on this! As a homeowner living near the Middle Fork, I’ve learned not to expect accurate, detailed predictions when these events loom. It is virtually impossible to say the magnitude and extent of each flood until it is upon us. On an hourly basis the numbers can vary dramatically up or down based on winds, small temperature changes, slower than expetced movement of a front, etc. Best advice I have is to be prepared for the worst case scenario, subscribe to Floodzilla’s email updates and check back with their website as well as the NW River Forecast and National weather center’s websites every few hours to see what is actually happening.
I have WeatherBug on my smartphone; when there’s an alert (such as High Winds or Flood Watch), I get an immediate notification (alarm and message). It’s quite handy.