How Historic is the Flood in the Pacific Northwest?

If you've flipped on your TV today, you've probably seen video of the flooding in Seattle, Portland, and nearby areas. Again, check the Raw Videos at right, some are very impressive.

CNN is calling this "historic flooding" so I wanted to see if I could quantify that. Here's a map of some of the flooded gauges. This USGS map shows rivers or creeks in a black color if they are experiencing record streamflows (the amount of water flowing through the gauge). That's a lot of black dots, and the situation is similar in northern Oregon.

Now let's talk "heights" - how high the water is compared to history (remember . According to NOAA AHPS, out of 44 forecast gauges, 30 are flooding, or are forecast to be flooding in the next 48 hours. I have seen two rivers, however, that are over their historical crests, in Naselle, WA and the Snoqualmie River at Carnation, WA. The Naselle River's highest point at that location was 19.26 ft on 03/18/1997 and the gauge read 19.98 feet yesterday (see graph below -- before the station stopped transmitting). Presumably the crest was higher than that.

These two stations certainly classify their flooding as "historic" and we will probably see more in the days ahead.