Friday, March 13, 2009

Major Weather Changes Coming

Today will be the last sunny, dry day for a long time. You can see the changes aloft as thin cirrus moves in aloft and contrails fill the sky. Contrails are a real sign of an approaching system since the air has to be close to saturation for them to form...the extra water vapor from combustion supplies the water needed to produce saturation and cloud droplets.
A weak front will approach tonight....and rain should start in the lowlands after midnight. The front should get through around breakfast time and then there will be a few hour break before the next...and stronger...frontal system moves in. Both of these fronts will bring considerable snow to the mountains. Colder air will move in behind the second front on Saturday night...and a few snow showers could reach the lowland hills on Sunday AM. But no big accumulation.
On Sunday, a low center will approach from the SW and this will bring more rain to the lowlands and snow to the mountains on Sunday afternoon. The low will bring strong winds to the northern Oregon coast and then breezy conditions over the Puget Sound lowlands on Sunday night.
The rest of the week remains cold and wet..with the mountains picking up lots of snow.

10 comments:

Joe said...

Good news for the skiers, and the ski hills, at least. And for our summer water supply of course.

Joseph Ratliff said...

Cliff,

I am curious about the approaching low from the SW...

Is it a 970 - 980mb low? Weaker? Stronger? Too early to tell?

The natural follow up would be...does this low have the potential of "winding up" before it reaches the coast?

andycottle said...

Hey Cliff, with GFS models showing COOL and unsettled conditions with low thicknesses in the lower 520`s, do you think through next week that Tiger Mountain may get a bit more on/off through the week?

andycottle said...

Sorry for the re-post. I spotted a typo.
-----------

Hey Cliff, with GFS models showing COOL and unsettled conditions with low thicknesses in the lower 520`s, do you think through next week that Tiger Mountain may get a bit more snow on/off through the week?

LJansen said...

Hey, Cliff! Just saw this:
"Spending bill includes money for Doppler" in the Aberdeen Daily World.

http://www.thedailyworld.com/articles/2009/03/14/local_news/03news.txt

"WASHINGTON, D.C. — A $410 billion spending bill signed into law by President Obama this week contains $2 million to go toward a special Doppler radar system along the Washington coast.

"Sen. Maria Cantwell, D-Wash., said the money for a new system is necessary to provide “our communities with a safety net to better predict severe storms.”

"It’s a project community leaders and weather experts across the region have been advocating for years, but everything came to a head after the December 2007 storm. Its severity caught most of the area unaware.

Harrison said...

Tiger Mt. will definately get some snow over the weekend on the hill. I lived up there when I was 8-11 years old and at around 990 feet, it was game on!!

sparky said...

I will miss the beautiful weather we had this past week!

Monsooning in West Olympia at 2:15pm.

andycottle said...

Sparky.... yeah, it`s been pretty nice last few days. Yesterday my high reached 58. Todays high so far...just 44 degrees!

Maybe a weak ridge for Thurs/Fri? Models right now aren`t sure what to think, but it appears the possibility is there.

andycottle said...

Cliff, kinda off topic I guess...but why is it that at times the UW-WRF GFS gets stuck updating? Maybe a glitch in the system?

It has`nt updated past hour 49 since this morning and I just checked and still hasn`t gone anywhere.

albion said...

Perhaps a half inch of snow here in Burton on Vashon Island at 8am.