As a bicyclist, I can say emphatically that the surface winds tends to blow stronger about an hour after sunrise and decrease about an hour before sunset. Typically, we have more in the afternoon (except those very hot summer days when you just can't seem to get a break). That said, there are always weather fronts that blow through increasing or decreasing the wind. Also, there is a definite seasonality to wind, blowing strongest in the spring and fall. However, in the northern portion of the country, the cold north winds in winter definitely correspond to high energy useage.
I believe the "misconception" that wind blows stonger at night comes from some actual data on high altitude radio towers (say 1000 ft) in the midwest. However, lower level and surface winds definitely decrease at night. Typical wind turbines are typically at a couple hundred feet.
All these generalizations are great, but each site is different and then there is the inherent random nature of weather. I have read that in certain areas (e.g., California) where coastal mountains interact with the ocean, there are daily fluctuations as the air heats up and rises during the day, cools and sinks at night.
The point of my post was to point out that during this NW spring there is lots of hydro and wind (several GW of new wind capacity added in the last 5 yrs). To deal with this current excess we have four options: 1) consume more, 2) export, 3) shut down, or 4) storage. Adding electric cars during this "driving season" is only one option. Shutting down excess capacity is fairly normal in the industry, it's just a matter of choosing which ones. Personally, I say shutting down the pollution-producing generation makes the most sense. If this is planned, then these plants can do their maintenance, then restart in July when the wind and water tend to decrease.