Wednesday, February 18, 2015

The Winter of 2070

There is a fascinating aspect of our present anomalously warm/snow-free winter.

It is very similar in many ways to what will be experienced in an average winter about a half-century in the future --more so than any recent year I can think of.


Hurricane Ridge (5200ft) on Monday Afternoon

As you all know, this winter has been much warmer than normal.  Here is the difference of the average temperature of the last 90 days from climatology (1980-2009).  Roughly 4F warmer than normal over the Northwest.

The UW Climate Impacts Group has published a report outlying their prediction of the future Northwest climate.  Here is a figure from that report showing predicted temperature change (relative to 1960-1989) with time.  They show the warming from various scenarios or RCPs (Representative Concentration Pathways).  RCP 8.5 (solid red line) is the most aggressive.   For reasons that I won't go into, many of my climate colleagues believe it it too aggressive and the RCP 4.5  (blue line) will prove closer to what will happen.  A number of climate model simulations were made, with the solid lines being the average of many runs (the range of these simulation is shown by the lighter lines).

Reading off the graph, it looks to me that a 4F warming from the end of the 20th century would occur around 2070.  If we choose the more aggressive RCP 8.5 scenario the answer would be a bit earlier (say 2050).


What about precipitation during the past 90 days?   This figure shows that the precipitation this year has been close to normal over most of the Northwest.  This is similar to what the climate models are suggesting for later in the century.

The snow pack is now running about 30-40% of normal, less in some places, more in others (see figure).  Similar to what a number of regional climate models are suggesting for around 2070.




So forget about checking out time machines or reading dry scientific reports on the future climate of our region.   You are living it right now, experiencing the conditions that will be typical 60 years in the future. 

We will have enough water 60 years from now for the urban populations, but skiing will be lousy at the lower elevations.  Snoqualmie Summit will be memory as a skiing venue.   And quite honestly, the winter temperatures will be more pleasant around here.   But the lack of snow, will bring serious consequences:   it will be bad for fish and there are serious problems for the Yakima agricultural area. This summer will be an interesting test of how our region deals with a very low snowpack that will be common late in the 21st century.    Keep in mind that winter is not over yet and the models are suggesting a major weather regime change late in the month, towards a wetter and colder pattern.


You don't need this...you are already in the future.




The Pacific Northwest Weather Workshop

Interested in attending the big local weather workshop of the region?  The Pacific Northwest Weather Workshop will be held in Seattle at the NOAA facility on February 27-28th.   Everyone is invited and the majority of talks are accessible to laypeople.  To attend you have to register or they won't let you in the gate.  There will be a major session on the Oso landslide.  There is a registration fee that covers refreshments and food, and special student pricing.  If interested, check out this website.

KPLU Climate Talk (SOLD OUT, but there is a waiting list)

If you want to hear me talk about the regional implications of global climate change in some detail, please come to my UW Kane Hall talk on March 11th.Sponsored by local public radio station KPLU, tickets for this event can be secured at this web site.

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