But all will change this week, as a significant shift in the large-scale flow pattern will bring moist, warm southwesterly flow to our region, accompanied by substantial rain in the mountains.
Tonight a ridge of high pressure sits over the West Coast (see map of 500 hPa heights and winds at 8 PM). It won't last.
By Wednesday at 11 PM, the ridge has deamplified and southwesterly flow will be over us. Expect showers on that day.
A ridge rebuilds temporarily on Thursday afternoon (5 PM shown)
If you were losing sleep because you were worried about filling Seattle's reservoirs, stop worrying. If you were losing sleep because of concerns about snow conditions for skiing, get a tranquilizer.
You want to know how much rain? Well, here is the 48h total amount ending 5 PM Thursday. A modest amount, but useful, particular since the high Olympics could get a few inches.
On the other hand, the 48h totals ending 5 PM Sunday will be enough to make old Pluvius proud, with several inches in all of mountains, 3-4 inches in the north Cascades, with lots of precipitation falling into the watershed of the Columbia River. Good for irrigation, fish, and power. Even parched northern California will get a piece of this.
No snow yet, then? If I want to do Mailbox this coming weekend, I'm safe? As a hiker and not a skier, I'm loving this winter.
ReplyDeleteCliff,
ReplyDeleteI'm glad Seattleites have nothing to worry about. What about all the communities that survive on surface water from snow melt and aquifers recharged from snow melt? Should they worry? How about a place like Hood River; an agricultural community heavily dependent on snowpack on Mt. Hood. Should they be losing sleep?
I'm so glad to hear the rain is coming. I was starting to water the plants in pots outside--not our typical March weather!
ReplyDeleteIs this true? What does it mean for us? http://www.sciencealert.com/this-year-has-been-declared-an-el-nino-year-here-s-what-that-means-for-you
ReplyDeleteWe've been under El Nino Modoki conditions for at least 2 months. So nice of NOAA to notice. :-)
ReplyDeleteGood for you hiking Mailbox! You're a tough atmospheric scientist!
ReplyDeleteMount Baker suspending operations.
ReplyDeletehttp://www.powder.com/stories/first-chair-blog/low-snow-closes-mt-baker-ski-area-indefinitely/
-Douglas
I hiked up Bald Mountain, 4800+ feet about 5 miles E. of Mt. Pilchuck on Sunday in warm sunshine. This area is in the convergence zone and would normally be snowbound through most of June if not later.
ReplyDeleteBut there was essentially no snow except a couple inches in the shady spots. Conditions similar to late October.
Presumably it will be a very early spring for the alpine flowers. One thing for sure- it will be in interesting year for hiking.