October 09, 2010

Heavy Rains

Driving home from downtown Seattle, I experienced very heavy rains and street flooding.

A good time to check out Seattle Rainwatch (http://www.atmos.washington.edu/SPU/), which has been funded by Seattle Public Utilities. Here is the latest 24-h rainfall:Some areas in the lowlands have gotten 2-2.5 inches of rain, with nearly the entire lowlands receive more than .5 inches. Except....almost no rain in some areas northeast of the Olympics in the rainshadow. It is very typical for the Hood Canal and Kitsap area to get hit by heavy rain during southerly and southeasterly flow as the air is forced upwards by the Olympics. Remember, you can NOT trust the radar precipitation amounts over the mountains, where substantial blockage occurs.

Looking at the current radar image, you can see the heavy rain from Seattle southwards and the rainshadowing to the north.
Temperatures have warmed tonight in many locations as a warm front has pushed northward. We are in fact in the middle of a plume of warm, moist air, known as an atmospheric river (see graphic of total warm vapor).

Later tonight a cold front will approach (yes, with more rain) and will move through tomorrow morning. Want dry conditions and sun tomorrow? No problem...head north and west for earlier breakout. But a warning...a convergence zone will form in the north Sound tomorrow afternoon, so avoid the zone between Everett and north Seattle if you don't like clouds!


  1. The rainshadow was very apparent in South Bellingham last night. As I was speaking on the phone with a friend in Seattle he mentioned the heavy rain. Here, it was dry, gusty and incredibly balmy! 67 degrees F at midnight!

  2. Quick FYI Cliff - something is up with your links - www.blogger.com keeps getting added to the front of the links. So "www.atmos.washington.edu/SPU/" became "www.blogger.com/www.atmos.washington.edu/SPU/"


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