Wednesday, November 6, 2019

One of the longest November dry periods in Northwest history

I am sure it has not escaped your attention that it has been generally dry and sunny the past few weeks over the region, a situation that is becoming increasingly unusual as it extends into our normally wet/stormy November.


By the end of today (Wednesday), we have gone through 12 days without measurable precipitation in Seattle (the last day of precipitation at Sea-Tac was October 25th).

To get an idea of how unusual such a dry streak is, consider the following graphic produced by Dr. Joe Zagrodnik, which shows that the longest dry streaks since 1950.  For the November period, the longest dry streak on record at SeaTac is 14 days.  12-days is tied for fourth place.
But our dry spell is not over yet.

Let's take a look at the ensemble forecast (models run many times, each a bit different) of accumulated precipitation at Sea-Tac Airport from the NOAA/NWS GEFS modeling system (see below).  None of the forecasts have any precipitation through 4 AM on November 9th (Saturday).  So two more days are in the bag.  We will tie the record dry streak of November (14)!  Enough to get weather enthusiasts excited.

But we have a real chance, but not a certainty, of completely busting the record.  The high resolution member of the ensemble (blue line) has no precipitation through November 14th as does several of the ensemble members (gray lines).   More members show some rain starting around November 13th.

What about the world-leading European Center ensemble (see below), which includes 51 members?  Dry through Friday.  We will tie the record.  Saturday is on the edge, with a number of runs with very light precipitation.  There really is not much precipitation through 2/3rds through the month.

So enjoy the next few days.  And perhaps we might take on another record--the lowest November precipitation---but that is one I would not bet on at this point in the month.

27 comments:

  1. I actually had to water some newly transplanted shrubs this week. Ugh. I like the old normal, will be grateful when/if the rain returns. So many dry 'pretty" days in Nov are not good for plants, wells, snow pack, salmon.

    ReplyDelete
  2. Cliff,
    What (if anything) can be extrapolated from this dry spell with regard to the longer term Nov-Jan precipitation forecast? Are we set up for a dry winter? Thanks as always for your great analysis!

    ReplyDelete
    Replies
    1. I think it is impossible to take a few days and make a claim for the whole WInter. The rain we had in Renton before this dry spell was heavy rain. Dumped real fast. Things can change real fast and no way can a few days determine the whole winter. Too many factors are involved that can change at any time.

      Delete
  3. I am utterly enjoying this odd clear streak! So GLAD to see the sun and feel its warmth at such a typically dreary time of year. :)

    ReplyDelete
  4. Cliff, it seems like in a recent blog you said it was about to start raining. What happened? It just proves what I said before, this climate is prone to what I call Entrenchment. The weather gets stuck in one mode or the other more than in other places I've lived.

    Believe it or not, I'm ready for the Pineapple Express. Better now than in the middle of the ski season.

    ReplyDelete
  5. I want my November back. All this sunny weather is making me miserable.

    ReplyDelete
    Replies
    1. trust me were i live i get snow nearly every nov in washington state foothills nut no not this nov

      Delete
  6. My kids and I raked up our leaves in a pile and have been having fun playing in them.since they are not all soggy this year!

    ReplyDelete
  7. I will take the sunshine, Cliff!

    ReplyDelete
  8. You want a dry streak? It has not rained since May 20th at my home in Arroyo Grande, CA, on the beautiful Central Coast of California.

    ReplyDelete
    Replies
    1. you're right is may not have but the cold air up were you are is pretty stale especially when there is fog and frost sorry to break but it is not dead dry

      Delete
  9. Weather anomalies, especially dry and/or hot ones, don’t really get me in the mood to celebrate these days, and not just because I’m a skier. I’d be interested to know if the warming Arctic and the wobbly jet stream have anything to do with this. The Northwest works as an ecosystem because of rain and snow. Just ask the fish.

    ReplyDelete
    Replies
    1. It just poured 2 weeks ago. SPU added 5 billion gallons of water to their reservoirs during that event, and then proceeded to gradually dump it because they are already ahead of supply for the water year. And since many rivers were at or near flood stage... it was good they had that room for the 5 billion gallons of water.

      https://www.seattle.gov/Documents/Departments/SPU/Services/Water/WaterSupply_11-05-2019.pdf

      Delete
    2. Glad to hear that! Time to start building snowpack, though. That’s what gets us through the summer.

      Delete
    3. Were you here in 2015? We had virtually zero snowpack the entire year and made it through the summer (in most locations, including Seattle, easily) due to winter rainfall and full reservoirs. Or this year: we had a very early meltout... there was no snowpack to speak of after June 1 and, again, statewide we had full reservoirs and plenty of water all summer.

      The "snowpack gets us through the summer" theme has been debunked - with clear facts - by many others but also Cliff - he was outspoken on it this very spring. Google it. In an average year the vast majority (90%) of snowpack is gone by June 30th. Our reservoirs get us through July, August and September, months that are historically very dry here (July in Seattle is drier than Phoenix). That is why Seattle's Cedar River water supply and reservoir system was established in 1901. Our city founders knew it too.

      Delete
  10. Is the warm arctic and lack of sea ice to blame for the wobbly jet stream that has caused this ridge pattern or was it possibly Typhoon energy in the westerlies that is throwing the pattern out of whack?

    ReplyDelete
  11. In addition, the freezing level has been very high - 11,000 - typical for the summer. I think the early snows have mostly melted.

    ReplyDelete
  12. The 14 day dry record was going to be surpassed sometime. Explaining this to my rubber boots is not without difficulties. A 70 year dataset is a lifetime. The conditions necessary to set new records much less frequent over a 70 year period. We just do not live long enough experience real weather extremes. I impressed the rubber boots by mentioning there is a 0.2% this year of a 500 year storm.

    ReplyDelete
  13. I still think Cliff should take a closer look at the amount of extreme weather (or lack of) records we've been breaking the past 2 or 3 years. Seems we are constantly breaking some kind of new record at a much higher rate than before. But I'd like to see the statistics on this.

    I.E. the rate of extreme weather events appears (to me) to be increasing, especially in the last 2 or 3 years.

    ReplyDelete
  14. The switch to Standard Time never happening again is a better deal but this works for now. Bird in hand etc blah blah. Hopefully no one is hoping for this lull to last the whole month. We need to get the snow pack going. Plus the East is getting brutalized by winter already. There needs to be a balance.

    ReplyDelete
  15. Wasn't the last post about how the rain was gonna return in full force after the first week on Nov?

    ReplyDelete
  16. We did our annual fall road trip to the Blue Mountains at the beginning of October, weather OK ducked the snow storms, saw through the fog, had fun. But last week when we saw how great the next four days were, off to a second fall trip - Moclips to Neah Bay.

    ReplyDelete
  17. This mini pause in rainfall has put a dent in normal water year precipitation. November is a very wet month normally. Even though October was a bit cooler and wetter than normal, SeaTac has gone from slightly over normal for the water year (starts on October 1) to about 4" below normal:

    https://www.wrh.noaa.gov/climate/yeardisp.php?wfo=sew&stn=KSEA&span=Water+Year&submit=Water+Year+Charts

    https://www.wrh.noaa.gov/climate/monthdisp.php?stn=KSEA&year=2019&mon=10&wfo=sew&p=temperature

    ReplyDelete
    Replies
    1. Current yr is 3.67" vs. 5.09" avg at Seatac as of 11/8. That can be made up in one day in the Nov-Dec period. And it's not "4" below normal", try more like an inch and change. And we're dumping water out of the reservoirs.

      Btw. We just finished 2019: 35.82 actual vs. 37.49 avg at Seatac. 96%. In a year that was declared a drought emergency. Bummer how those facts mess up all the fear-mongering. However: I predict more fear-mongering because facts don't mean much anymore.

      Delete
    2. sunsnow12 with another expresso-shot of reality to temper alarmism. Thank you.

      Delete
  18. Quick, Jay Inslee! Declare another drought emergency! LOL

    ReplyDelete
  19. After you see what the meteorological professionals say, perhaps ask a salmon fisherman about what they think about all this. Then ask a farmer/gardener. Maybe ask a skier next. Ask a politician last.....or maybe just don't ask them at all.

    ReplyDelete