Heavy precipitation has moved into Puget Sound country. Here is the lightning over the past 24 hr (basically all day Tuesday). The most recent is yellow, followed by reds and purple. The Cascades have been hit very hard with lightning and right now the folks around Bellingham are getting the flashes.
Last night thunderstorms hit portions of Western Washington and right now (3 PM) a band of heavy showers is moving northward towards Puget Sound. Note that particularly heavy precipitation is associated with thunderstorms over the southern Cascades (red colors).
Here are recent lightning strokes. The Cascades are getting hit by multiple strokes.
The forcing for all this activity is an upper level trough/low that is moving towards us now and which will circle around the area for the next day. To illustrate, here are the upper level forecast maps (500 hPa) at 5 AM and 11 AM on Wednesday.
Take a look at the 24h precipitation ending about 6 PM today. The south Cascades have been hammered by the thunderstorms, with some locations getting 2-3 inches,
Large amounts of precipitation for this time of the year...as much as 1-2 inches over the Cascades..are forecast during the next 72 h (see map). Eastern Washington will get a lot of precipitation, and they need it.