March 06, 2011

Good News and Bad News


The good news for some is that there is little chance of lowland snow for the next week, which probably means we are out of the woods on that. Lowland DOTs can relax. The bad news for some...the faucet is about to be turned on.

Interestingly, although the last month has been substantially cooler than normal (consistent with La Nina!), we have in fact been drier than normal. (see graph for Seattle...blue is normal) That is going to end.

Now tomorrow will be pretty much dry, but then we will experience a series of storms...and I mean a lot of them during the next week. The flow pattern will be generally southwesterly, with the jet stream and moist southwesterly air headed our way. (see upper level map for an example).Not a major flooding situation, but just persistent moderate rain, with storms every day or so.

Want to see? Here is the precipitation for the next 48h.
And here is for the next 48 h. Quite a bit wetter, with some mountain locations getting 2-5 inches of precipitation (multiply by roughly 10 to get snowfall amounts).

And here is another 48h:
The spreading moss on my lawn will be very, very happy.

The air mass will be cool enough that most of this precipitation will fall as snow in the mountains...which is great for skiers and for the water supply.

7 comments:

  1. Hi Cliff,
    Been enjoying your blog a lot. Used to live in PT, and hope to return in the next year.
    Where do you get these weather maps? They're great. Thanks.
    Ken

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  2. "The air mass will be cool enough that most of this precipitation will fall as snow...which is great for skiers and for the water supply."


    You might want to edit that to say that most of the precip IN THE MOUNTAINS will fall as snow....


    You don't want to start any rumors of another "snowmageddon"!

    Thanks for the heads up Cliff....love your blog!

    ReplyDelete
  3. It hasn't felt drier than normal to me the last couple weeks, so I will say "ugh" to more rain.

    ReplyDelete
  4. Cliff, interesting graph you presented for the last month of precip at SeaTac. If you look at the water year so far (begins Oct 1), the precip is actually ahead of "normal":
    Water year charts for Seattle

    ReplyDelete
  5. Every Spring as we move into the "lost of never-ending days of rain" I need to remind myself that at least it is good for our water supply.

    Also, it helps taking our annual trip down to AZ where outside of Phoenix they have subdivisions which are sold with guarantees that "the water supply will last fifty years!" (of course those guarantees are never accurate). But think about it - can you imagine even considering buying a house where your water supply is finite? No matter how long that finite time is - it is still finite!

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  6. Dennis, that's NWS water data is interesting. We've had more than average rainfall but less than average snowfall. As Cliff notes however, the mountains are catching up and are looking good now. (I look at http://www.wcc.nrcs.usda.gov/cgibin/snowup-graph.pl?state=WA)

    Maybe this week's activity will push the south and central Cascades up in to the 90s relative to average.

    ReplyDelete

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