Who's ready for a blast from the past?
Anyways, I was just musing about the weather we're having lately and doing some web-hopping to find out how much worse this year has really been compared to normal. Actually it's not as bad as perception would lead most of us to believe.
Last summer was about normal temerature-wise, just cloudier than usual. Most of the months of the past year have seen temperatures ranging from about 1 degree above to 2 degrees below normal. Not really that bad in the grand scheme of things. Still, it shows a trend that may be attributable to a return to the cool phase of Pacific Decadal Oscillation, which we were in from about 1947-76. This clearly had an effect on our climate. Not only were some winters more severe; summers were often cooler and many of the region's glaciers advanced or at least stopped receding for a couple decades.
With so many poorly understood variables, there's no telling what the weather of the future will bring. Nevertheless, I think it's a good bet that we will see a return to an overall colder climate for the next 20 years in the Pacific Northwest. But that won't stop me from planting whatever I want... LOL.
I also found this article.... (link below)
Deviation from 59 year average @ Sea-Tac airport (from http://www.wrcc.dri.edu/cgi-bin/cliMONtavt.pl?wa7473)
2007
August +0.73
September -0.46
October -1.82
November -0.63
December -0.94
2008
January -1.26
February +1.20
March -1.73
April -2.37
May +0.74
June -2.03
July +0.01
August... still just above the mean as of today. That may change this week, however.
I should do a broader geographical sample including areas that have been less effected by urbanization.
The following thread was started by Ian on August 26, 2008 at 10:01 pm PST
Then the cold phase of the decadal oscillation may be enough to cancel out the effects of increased CO2 levels, at least here in the PNW. Heck, a fraction of the heat we had over the past 15 years or so might have been due to a warm phase! The PNW temperature was reported as having risen by about 1.3 degrees Celsius since the mid-20th century (don't quote me on the figures, they are only from memory!) which is MORE than the global temperature as a whole. We may be entering a phase where global warming is underrepresented, instead of overrepresented, in the PNW.
But that doesn't mean human-induced climate change isn't real, or that things will go back to the way they were in the 1950s and 60s. One thing that is radically different today is the polar climate. Sea ice is much smaller than it was 50 years ago and most polar and subpolar regions are reporting shorter, warmer winters. That means that there will be less Arctic air available for deep freezes in the temperate latitudes.
So even though we may go back into a generally cool weather trend, it might end up more closely resembling the climate of Britain: chilly springs and mild summers, but not much extreme cold in the winter.
The above followup was added by Eric Eug. on August 27, 2008 at 12:05 am PST.
The link you provided has another link to a world map depiction the affects of the warm faze of PDO from 1982 - 1996. I have linked this below. Note that the PNW is actually on the edge of a cool zone. The question is, does the warm faze of the PDO actually warm the PNW AND what does the map look like for a warm faze of the PDO?
The above followup was added by Jeff, Victoria, 8b on August 28, 2008 at 10:32 am PST.
Interesting map for sure, but it doesn't really show what the warm PDO does, only what we're experiencing right now compared to that warm PDO 15 year interval. And it fascinates me that the ocean just west of us is so comparatively cold right now...what is that doing to our weather patterns? For several years recently the Pacific just offshore of us was almost record warm, several degrees above average...now it's obviously well below average, hmmm.
Also as Eric pointed out, look how comparatively warm the arctic is just north of Alaska and Eastern Siberia...seriously "overheated"...does that affect the intensity of arctic outflows which are my main concern regarding winter plant survival here.
The above followup was added by Glen in Surrey on August 28, 2008 at 8:19 pm PST.
After more followup with Ian's article, I see what seems to be a summary of how the warm and cool cycles affect the Pacific area...in the provided link.
According to the two globes pictured, it's hard to be optimistic about our longterm weather patterns if we return to the cool phase...looks like the sea temps offshore and wind patterns will both be against us here. Is that what others conclude from these depictions?
The above followup was added by Glen in Surrey on August 28, 2008 at 8:38 pm PST.
Well I really don't have all the answers but that map does look like the onset of a cool phase pattern. The cold pocket to our northwest is typical of the cool phase (and may be in part responsible for our lousy weather of late) and the warm pocket to the southwest could be expected to diminish. We will just have to see what happens.
I'm not sure about the warmer Arctic and it's certainly an interesting question. Let's remember though that even during the ice ages when the top half of North America was buried under miles of ice, it is thought that the Arctic Ocean was about as ice-free as it is now. (how someone figured that out I'm not sure, but I think it's widely accepted). It seems to me like North Pacific Ocean temperatures would play more of a role in whether cold air is pulled in our direction since it just takes a big, persistent high pressure dome out over the Pacific in winter (now an extremely rare event for more than a few days) to lock us into a frigid pattern. But of course I'm no expert.
The above followup was added by Ian on August 28, 2008 at 11:35 pm PST.
The T. wagnerianus at the Washington State capitol campus made it through the fifties and sixties. Of course we had more snow with the cold fronts during those times, which insulates plants.
The above followup was added by Issaquah John on August 29, 2008 at 7:11 am PST.
I could have swore that we just got done with a 30-40yr old cool wet cycle and now were headed for dryer stage. This came out about 8-10yrs ago.
Does anyone remember this?
The above followup was added by Roger on August 30, 2008 at 1:17 pm PST.
Was that the wet PNW was going to get wetter,while we in Nor Cal get warmer storms and less snow,more rain. A faster start to a warmer spring and by 2075 near present day San Diego summers,if not winters. That would mean earlier spring,warmer summer nights. What that will do to the Redwoods,bays, and our NorCal oaks is not good.
The PNW,may have cooler summers as the rainy season goes on and on..
That darn Sou Cal may not see any change in their lifestyle since they get water from the Colorado. San Diego and L.A. might have Cabo winters by 2075 and still they will have lush lawns..they have the money and pull-lol.
The above followup was added by Stan on August 31, 2008 at 7:48 am PST.
We may understand (or think we understand) various individual factors that impact our weather (greenhouse gas emissions, El Nino, La Nina, PDO, AMO, MOO, sun spots, Milankovitch cycle and who knows what else is out there) but no one has yet been able to put all of them in one reliable model to predict the likely overall impact. My strategy in the meantime: do not rely solely on tender exotics for your landscaping needs and bring in into the garden some bullet-proof or reasonably hardy plants as well. As an example, last week, I bought Olea europea (Arbequina), which I may loose in an unusually cold winter, but I also picked up bullet-proof Shepherdia argentea and hardy Zanthoxylum piperitum, etc. Or how about some hardy, interesting perennials under the canopy or in between tender shrubs or perennials. I overlooked these two beauties many times in the past only bying them this past summer. Tricyrtis "Empress"
The above followup was added by Vlad Pomajzl, Saltspring on August 31, 2008 at 10:40 am PST.
Or this Kirengeshome, which is just about to start blooming. Regardless of what the up coming winter will be, we could do much worse. Just watch what will happen in the next hours on the southern US coast. I believe we have one contributor to this Board sitting in the path of Gustav. Ryan hope you will be O.K.
The above followup was added by Vlad Pomajzl, Salstpring on August 31, 2008 at 10:44 am PST.
Good for you, buying a named olea europea! Arbequina does seem to be the most "fruitful" (or at least the most precocious) of all the olives I have. This year, with our "La Nina" summer, they have by far the most olives per foot of branch - in fact I would say mine are loaded this year. Some other varieties did not much fruit at all, and some are just loaded with shot berries (a sign of poor polination). See photo of Arbequina fruit taken this morning below - the tree was planted in 2006...
Good luck with yours - I bet you have fruit next year!
The above followup was added by DavidInAmityOr,Z8 on August 31, 2008 at 11:00 am PST.
If you remember from our last talk I already had three olives but of uncertain varieties. I planted one but decided to play it safe with the next one and bought this tree. It is already loaded with olives. However, I don't think it will go out before the next spring. It may be getting a bit late plus I don't have a good site for it right now.
The above followup was added by Vlad Pomajzl, Saltspring on August 31, 2008 at 7:08 pm PST.