Wednesday, July 31, 2019

The Driest Week of the Year Brings Rain and the Summer Outlook

We are now near the halfway point of summer, and it is clear that this summer has been the best in several years-- temperate, dry with brief rain periods, and very little smoke. 

July brought above normal rainfall for much of the region, with Seattle getting 1.15 inches, .45 inches above normal.  Temperatures were cooler than normal over the Cascades and eastern WA, but warmer than normal in parts of western WA.  Cool in wildfire land.


 Thursday will be warm in western WA, with highs in the mid-80s away from the water.

But our warm, dry days are about to get another interruption, with a stronger than normal Pacific front making landfall on Friday.

The front will be approaching the coast at 11 AM Thursday (see 3-h precipitation ending that time below)


And will sweep in on Friday morning.  Not a super amount of rain on Friday in Puget Sound, but enough to cool temperatures by at least 10F and wet things down. 


The accumulated precipitation through 5 PM Saturday show an important story:  SW British Columbia will get hit hard with rain, with the NW corner of our state getting the most.  Forgot much fire activity in southern BC--- this is going to be a low-fire season there.  Which means less smoke for us.


The signature weather pattern this summer has been the persistent trough offshore--something that is very evident in the upper level map for 2 AM on Friday morning.  We started seeing this pattern consistently in late June and it has remained remarkable constant over time.  Such troughing keeps us cooler than normal.


And now it is time to look at for the rest of the summer!  Here is the predicted total precipitation through Sept 13th by the vaunted European Center model ensemble system (see below).  Wow.  BC is quite wet, as is NW Washington.  SE Alaska in nutty wet.  You have to feel sorry for folks taking cruises up there.

The next map shows the difference of that precipitation from normal.  Wetter than normal over most of the region.  Crazy wet in SW British  Columbia

The take away. This is going to be a quiet wildfire season in the Northwest, with average or fewer than normal fires.  If you are planning a vacation on Vancouver Island, take rain gear. And a tarp.  And more rain gear.


18 comments:

  1. I wonder if this wetter than normal summer will mean a pattern change come September into one of those Indian summers where the Fall rains don't arrive until mid to late October. This type of pattern was common in the 80s and early 90s. Not so common anymore. 2012 was the last true Indian summer here.

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    1. I was wondering the same thing. Great minds... (-:

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  2. Darn, I'm on vacation on a mini-cruise from Juneau to Seattle from mid-September to the end of the month. Rain for those two weeks?

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    1. Nobody knows what the weather will be like for your vacation in two months. Long range modeling has improved, but forecasting accuracy still falls off dramatically after 96-120 hours out. Cliff would like you to believe otherwise, because he, like the overwhelming majority of those dwelling in Pugetopolis, worship the false god of technology.

      Check out Wasatch Weather Weenies for a reality check on long range modeling.

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    2. It will rain for 2 hours on 3 of your days then be nice for the other 11 days

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  3. In the macro, it is going to be a quiet fire season in W. Washington. Where I live, however, I am worried. South Whidbey Island this year missed much of the rain Seattle received. Our beloved rain shadow has caused us to be drier than 2015. We've received only 1.64" of rain May 1st through Aug 1st and .39" for June through July.

    We've had two brush fires in the last week caused by careless human activity. We were lucky the winds were calm and our volunteer firefighters were quick to put them out.

    I am very worried about the associated winds with this system. Our forests are dangerously dry, particularly around the town of Langley, and a single spark or cigarette butt will likely start a fire. Should this happen on a windy day, I fear we could have a bad situation. We wont be out of this situation until we have a season-ending soak.

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  4. I look at some of these maps and wonder what stations have been used as historic "data" for the Cascades end of Whatcom County. The precip for the current three Julys in Glacier: 2017 .05", 2018 .91", 2019 2.54" This year, WET. It irks me that NWS and others appear to use lowlands "banana belt" stations. The figures for 2015 were way off (which has led to an outrageous "snow drought" narrative); 2016...similarly wrong for the mountains up here.

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  5. ". . . take rain gear. And a tarp. And more rain gear." Made me giggle, Cliff!

    The larger images in this post are very effective. I'm so happy to know wildfires are expected to be average or less.

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  6. I suspect most Alaskans won't mind the rain and cooler temps, they need it this sumner.

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  7. Not everywhere on Vancouver Island has been getting soaked - mostly just places where not many people live. In Victoria we had 17.8 mm (0.70") of rain for the month of July. That's a bit wetter than normal, but still pretty dry.

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  8. Dewpoint of 65F at UW right now. Blech!

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  9. Nope, don't feel sorry for vacation cruisers to SE Alaska one bit. It's a RAIN FOREST! That's what's supposed to happen, and part of the real experience. :-)

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  10. This sounds like "old times" for those of us who have lived here for 20 years or more.
    Happy to see the rain, even if it's inconvenient.

    We "cruised" from the Everett area to Nanaimo BC on our motor-sailor back then. It rained most of the way. We mostly motored, because managing sails in a downpour was no fun. And sailing meant very slo-o-ow progress ~ tacking (zig-zagging) back and forth. It was fairly warm most of the way and we were younger, so we put up with being wet, with infusions of hot coffee, snacks, and food cooked on very small stove.

    We were younger and used to difficult conditions from our earlier mountaineering activities. We laughed through a lot of this.

    Wonderful memories.

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  11. On the topic of summer temperatures, did the thermometer anomaly at SeaTac, about which you wrote a year or so ago, ever get resolved?

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  12. Late winter, now a late summer. Climatological momentum is real

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    1. Nothing out of ordinary varation. I guess you don't really know the difference between climate and weather. Your cult used to talk about it all the time, but in recent years that mantra has been dropped. Any lie for the cause, huh?

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  13. I wonder what next summer has in store for us? Would approaching the solar minimum increase our likelihood for La Nina and cooler temperatures? I remember that happened in 2010 and 2011.

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