We are living through a historic warm period. No, not the new record for days above 90, 80, or 70 here in Portland. (But we will break the 70 degree record tomorrow)
Not the hottest summer on record, or the warmest winter on record, or the warmest January and June temperatures ever recorded at Government Camp (70 & 93).
I’m talking about the BIG PICTURE. We have been consistently warm for almost two years now. The last time we had anything close to a cool month across a good portion of the Pacific Northwest was way back in February 2014! Yes, we had a cold spell last November, but the warm temperatures in other parts of the month cancelled out that cold.
February 2014 was below normal here, although not really a “cold” month.
You have to go all the way back to December 2013 to find a COLD month
So far this year (through September) is the warmest on record in most of the Pacific Northwest.
In Oregon climate zone #2 (lower elevations westside) it IS the warmest on record:
Most likely next year will be warmer than normal as well with El Nino dominating the first half of the year. Calendar year 2014 was the 2nd warmest in our area.
This is quite a turnaround from 2010-2011 when short-term trends showed cooling through the early 2000s. During that time I would sometimes get emails from critics about how our climate was “cooling”. Well, if you cherry-pick the data you can often find a trend that agrees with your view. I prefer to look at the real big picture:
Our climate is slowly warming (regardless of the reason) but the extreme warmth of the past 1.5 years is likely a highly anomalous event that may not be repeated for a while.
Many times I’ve discussed the reasons for the warmth:
- Upper level ridging (high pressure) has tended to want to hang around the West Coast or just west/northwest of us for extended periods beginning in January 2014.
- Warmer than normal sea surface temperatures in the eastern Pacific. If air comes off the ocean much of the year then that air will be warmed more in this case.
It’s possible #1 goes away anytime, but #2 will likely stay put through this El Nino winter. Thus another mild winter as mentioned in my El Nino postings (see tabs above main blog posting).
If we swing to La Nina conditions next year, that could very well put us back to cooler again. But in our gradually warming climate the “cool years” will not be as cool in the future.
Chief Meteorologist Mark Nelsen