A Wet Memorial Day

 If you are planning an outdoor excursion on Memorial Day (Monday), I have a suggestion:  bring an umbrella and wear a warm jacket.

Consider the latest forecasts.  The total precipitation through Sunday at 5 PM shows only a little drizzle on the windward side of some local terrain.

But on Monday, a strong upper-level trough will move in (see upper level map below, with blue indicating lower pressure than normal...troughing), producing much colder than normal temperatures (highs in th 50s) and substantial precipitation.

Here is the forecast precipitation total through Tuesday morning:  western Oregon and Washington will be thoroughly watered down, with some rain extended over the Cascades into Yakima and Kittitas counties. 

More precipitation is predicted for later in the week.  In fact, the regional totals through early June are scary wet (see below).  Perhaps this will comfort folks worried about drought. 😊

It is important to note that Memorial Day weekend is infamous for wet conditions in our region.  It illustrates this soggy fact, below is a plot of the historical precipitation at SeaTec from May 23 through May 28.

Most years have some precipitation over that period...and occasionally it gets quite wet (almost 2 inches).   This year, we will enjoy about a half inch over that period, so we will be a little wetter than normal.     That's fine...we can use it.