4/20/2011

You're not imagining it - spring has been gloomier than normal this year around WA. Not only has it been relatively cool across the state, but most locations have been wetter than normal as well. And it hasn't only been the amount of precipitation; it's been the frequency of precipitation that has had most WA residents complaining. In order to verify this idea, we took a look at the number of days with measurable precipitation (0.01" or greater) for this season compared to normal for a number of WA locations. Table 1 shows the average number of wet days for March and April using the entire record for each station, the number of wet days for March and the first 19 days of April for this year, and the difference from normal. Every station listed has had more wet days than usual for March and April... and April isn't even complete yet!

The long term record was examined further for a few of these stations, and for Pullman, this year has had the most wet days in March and April than any other year in the record dating back to 1940. For Everett, only 2 years since 1915 have had more March and April rainy days. Hoquiam has had 3 years with more March and April wet days since records began in 1953 and Spokane has had only 6 years with more wet spring days since records began in the late 1880s. All this means that the grousing about the weather in WA during the last couple of months has some justification. Naturally folks are curious about when the weather is liable to turn around, especially in light of the relatively inclement weather of the late spring and early summer of 2010. In this regard, it is not just our skies but also our crystal ball that is cloudy... but at least there is little reason to expect that the weather will necessarily remain foul in the coming months.

Table 1: The longterm average number of days with measurable precipitation (at least 0.01") for March and April for several WA stations, the number of wet days in March and April of 2011, and the difference from normal. Note that April count for 2011 is only through April 19 while the longterm average counts the entire month.