And the the 1 PM radar showed storms moving northward on the western side of the Cascades.
The anvils from the approaching storms was apparent at 1 PM from the SpaceNeedle PanoCan.
This morning's forecast models predicts quite an event this afternoon. The UW super-high resolution (4/3 km grid spacing) WRF model indicates major thunderstorms on the western slopes of the Cascades at 2 PM.
And by 5 PM, western Washington is covered, as well as the northern Oregon Cascades and portions of southeast Washington.
Why all the action? The atmosphere is relatively unstable, with high levels of CAPE (Convective Available Potential Energy)--some places of 1000 J per km (blue colors).
And there is upward motion associated with an upper level low on the coast (see 500 hPa, ~18,000 ft) map below.
The problem of these events for thunderstorm lovers in Seattle is that the storms tend to weaken rapidly moving west from the Cascades--but we well might enjoy a few showers from the convection and maybe a few boomers.
Enjoy the show.