March 25, 2019

Aurora Forecast Bust and Dry Western Washington

Well, I have to admit disappointment, both in the lack of auroral activity over Washington on Saturday and the poor forecast by the NOAA Space Weather Center of the Planetary K-index, Kp, which is used to characterize the magnitude of geomagnetic storms.

As noted in my last blog, there was a solar disturbance last Wednesday and the NOAA center predicted that that impacts would be felt on Saturday, with the potential for an evening aurora.

The forecast of Kp made the day before is shown below, with the verification right below.  Values over roughly four suggest a moderate geomagnetic storm that might provoke some decent auroral displays.  The initiation was predicted to occur Saturday morning (18 h is 11 AM).

But what occurred was much less and much later.  The "event" started on Sunday afternoon and was only reach a Kp of 2.

There was some minimal auroral activity Sunday night, but not in our area. 

Well, I suspect that predicting the propagation of particles from the sun to the earth is far more difficult than weather prediction, so I won't be critical of the NOAA folks.  Still disappointed though.

And we are getting some light rain tonight, which is welcome.  The last month has been dry for western Washington, in some places more than 4 inches below normal.  But most of the west has been wetter than normal, particularly around the Bay Area.

As shown in the cumulative one-month rainfall below, Sea Tac Airport received roughly 2.5 inches less than normal (cyan is normal, purple is observed)
But Pasco, in eastern WA, was about right:
The dry conditions in western Washington were very obvious over the weekend when I was busy turning over the soil in my vegetable garden....the soil was quite dry through depth. Sure enough the soil moisture anomaly (difference from normal) for yesterday showed drier than normal soil conditions.  And one good thing about the rain--it should lessen the pollen count a bit.


  1. Yes indeed, it seems that the typical belt of Pacific rain has been located a bit further south for a bit. And I've wondered what's contributed to that, if anything, beyond normal variability.

    What I expect more than anything in the Pacific Northwest is variation (sometimes, quite wide swings). Whatever the situation may be, I'll track this summer's lows which have been in a downward trend in the last few years (mere observation; zero speculation on my part).

    As for gardening, I learned decades ago that however promising a spring may seem, it's risky to plant "starts" before June, even at low elevations, here in the mountains. We've had a mere handful of nights above 32 F since the start of the year. Clear skies only exacerbate that.

  2. I recall a few aurora displays seen in eastern Washington in the late 1950's. They were spectacular!
    Those years saw a lot of sky watching what with Sputnik and my growing interest in astronomy.

  3. Yes, very dry. As some of the precipitation fell as snow, my general impression is that there has been very little rain so far this year.

    As the jet stream returns northward, one would expect a wet March and April (isn't that the usual El Nino pattern?) but it seems that so far that is not the program... does that mean the jet stream will be over us only briefly before summer?

  4. Thanks Cliff. Always a pleasure to read what you have to say, even when I disagree.

    Interested in the Aurora forecast / foercasting? Take a look at They had a good explanation of the mechanics of how solar space weather works on March 23. Check their archives.

  5. I have never seen the Northern Lights in the Seattle area and that's in 20+ years of actively trying. I may...may have seen the faintest of glimmers on the far northern horizon once, but if so it was very underwhelming.

    Whenever you see the amazing shots in the newspaper they are in photographic manipulations. If you were in the exact same location as the photographer you would see little to nothing since your eye does not pick it up like the camera does, not to mention other tricks like long exposures and contrast increase.

    I would love to see the Northern Lights someday, but will have to make my way to Alaska to see a real show. I discount any forecasts around here for such shows. They just don't turn out.

  6. I've seen auroras 4 times in my life: On a high pass in Colorado, probably in the late fall or winter; once briefly near Bellingham, in July back in the 80's and only near the horizon; in October of either 2004 or 2005 from my house; and in the mountains near Hope, B.C. in July of 2012 or 2013. The display in B.C. lasted for hours and flickered in bars of white. But only the one I saw over my house in Oct 2004 was colored- red, green, and white. It flickered in bars of light, and there was an interesting crescent of light overhead.

  7. I suppose a trip to Alaska is in my future! I do want to experience the aurora borealis lights as well as lesser developed parts of the state.

    My disappointment about viewing the aurora in WA is tempered by how happy I am the rain lessens the pollen.

    Of course, there is so much beauty here in WA just looking out your window or stepping outside the door. At the moment, I can't get enough of looking at the snow capped mountains and being in nature in general.

  8. Growing up in south dakota we’d see them all the time in the northern skies, there is no way to explain the night sky in a rural setting with no ligh pollution. I’d look up as a kid and go “What in tarnations! What is this complex light show supposed to be? I’m still annoyed at the night sky in Whatcom county. Seen too much growing up.
    in summary. If it wasn’t for the high population in out region we’d see green and quite often.

  9. "Yes, very dry.... my general impression is that there has been very little rain so far this year."

    Seatac precip for the water year: 25.06" vs 27.53" normal or 91%. 91% is not remotely "very dry". This year has been wet and in some places very wet. February itself was at 132% of normal, but interesting.... none of the drought-mongers talked about that, or the fact SPU has been dumping water for over 4 weeks (and still are) as they make room for the snow melt that will be ongoing through May and likely June...

    On another subject... anyone for the over/under on if/when they open the new CA Oroville Dam spillway? Articles today are speculating that after next week's storm it could happen... stay tuned...

  10. Here's a great webcam for observing clouds (especially lenticular) and aurora on the south side of Mt Adams pointing north. Not a lot of light pollution and the webcam owner is very good about increasing the ISO setting when aurora are forecasted.

  11. Saw Northern Lights sometime in the late '70's standing in the front yard of our married student housing residence in Corvallis. We had only been in Oregon several years up to then and I did not fully grasp how unusual the display was for this latitude. Good excuse for not being in the lab though!

  12. @Sulla, that is not quite true. The camera does pick up more then eye can see, especially colors, but the camera cannot convey the rapid motion that often happens with aurora, so this cuts both ways.

    The main issue for us in Seattle is getting away from the city lights. To really have a great view of the aurora, you need to be in a place where the Milky Way (if overhead) would be obvious and bright. There aren't many places left where it is this dark, at least west of the Cascades. Then the issue becomes, Do I drive 2+ hours to a suitable site when odds of a bust are maybe 2 in 3? (The odds are rarely better than this no matter what the forecasters tell you.)

    I have seen at least 8-10 displays in Illinois and Washington states since the late 90s, but there have been relatively few grand displays in Washington since the early 2000s. The last solar cycle was quite weak, and the next one may or may not be any better. Keep trying! but a trip to Alaska or Iceland is a surer bet :)

  13. Not a bust. Visible from south Vashon tonight.

  14. November, December and most of January was wetter than normal just north of the border in Vancouver BC. Yes we have had some dry summers over the past few years but also in recent years we have had wetter than normal water years. (Oct 1-Sep 30). For sure 2015-2016,2016-2017 and 2017-2018 saw above normal precip totals for the "water year" over much of SW BC and Western Washington. It seems the the dry months have been very dry( below normal) but because of some extremely wet periods in the fall and winter,the overall totals for those years i mentioned, ended up being above normal for the water year. I think there have been more quick but heavy rain events that also skew the numbers a little. I know in Coquitlam BC we had copious amounts of total rainfall this past November (well above normal) but most of it came on only a few days and we even had more dry and sunny days than normal despite the massive rainfall monthly total.

  15. We saw the aurora last night (March 26) from south Maury Island. Not colorful, but streaming and shimmering, emanating from below and slightly right of the northern star. A cone of light at times, splitting into a fork, then going away, then re-appearing. My 16-year old said it was green, but my old eyes could not see the color. Most people on FB claimed I was smoking something or seeing sirrus clouds and/or city lights. Please tell me you got another report from someone!


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