Saturday, April 11, 2009


The visible satellite picture today show two things...the clouds on the western side of the Cascades and the approaching weather system offshore. Eastern Washington and Oregon are nearly clear and sunny. We have now switched to the period when eastern Washington no longer clouds in...so very frequently they are clear, when the west side is in clouds. A good time to visit your favorite winery and dry-land hike.

The approaching system is stronger than most this time of the year and the low center will cross northern Vancouver Island (see image for 8 AM tomorrow). It will get breezy later tomorrow am as the low passes north of us, but the big issue will be rain.

The two images that follow show you the predicted 24-h precipitation ending 5 PM tomorrow and Monday. Quite wet tomorrow--with the model going for 2-5 inches on some windward slopes! And a spectacular rainshadow. Head to Sequim tomorrow...somewhere around there may be completely dry...maybe even with some sun breaks. The second day precip is still signficant..but those are mainly showers...with a strong Puget Sound convergence zone (see the next figure for 11 PM on Sunday). Behind the system, temperatures and the snow level will drop...and expect snow..lots of it above 1500 ft (check on the 24h snow ending Monday at 5 AM)

8 comments:

JewelyaZ said...

Wow, here it comes, like you said. ;-) I'm glad we got the dirt in the new raised bed today!

andycottle said...

Cliff, guess you could`nt think of a title for this blog. Maybe something like..."Wet & unsettled"?

It will be cool and a bit on the Wet side for sure. But I`m looking forward to later next week as models are showing a nice, warm ridge. EURO seems to be the strongest. But it`ll be nice to see warm sunshine again if comes to fruition.

andycottle said...

Also....you think there will be any new snow fall accumulations up at Tiger Mountain when the cooler air moves in?

Was up there last Sat and there was about 4ft or so of snow up there. Now yesterday when I was up there, a few patches were left, but majority of snow had melted with in a weeks time. Though at West Tiger2, there were still some small snow banks left.

Keeping one's head above water said...

they are saying t-storms here in chehalis on monday. but when anything does come here, it seems to split: either they go toward the mountains or go around towards PeEll. Is there something about the topography here in SW Washington that allows for this to happen?

Cliff Mass Weather Blog said...

Keeping... sinking off the mts of sw washington can weaken the thunderstorms/convection over the lee areas (like Chehalis)...Pe Ell is inthe terrain...and thus they get more..cliff

JewelyaZ said...

Did the system stall or not come onshore as fast as it was predicted to? Here in east Bellevue, we've had a peak gust of 4.3 mph today and very little rain... I thought it would be more exciting by now?

Not really complaining, just wondering if things have shifted out a few hours.

Joan Neslund said...

11 Miles S Stehekin WA
48.2°N 120.75°W (Elev. 3224 ft)
Holden Village

Easter morning, we awoke to about 2 inches of fresh snow. It snowed till about 11am and then turned to rain. Still coming down.

Total snow is now at 223 inches. We have just now begun to dig out a bit but no shoveling today.

evilzenscientist said...

Wow - what a wet Sunday.

31mm of rain since midnight in downtown Issaquah - even the normally rain-light gauge from the City of Issaquah shows 0.8" (20mm)

http://weather.ci.issaquah.wa.us/current_monitor.htm