Wednesday, January 20, 2010

Warmest January in Seattle History?

It could happen...

Lets face it, the temperatures this month have been amazingly warm...we are experiencing April temperatures in mid January. Take a look at the plot of temperatures this month versus the daily average maxima and minima (plot).Many of our days have hit highs 5-13 F ABOVE NORMAL, and our minima have generally been higher than the normal maxes. Remarkable. The average temperature this month has been 47.55F--a month when the climatological average is
around 40F--7.5F above normal!!! The warmth this month is essentially due to the generally warm southwesterly flow, although for the last few days, downslope warming has added several degrees.

The warmest January on record was in 2006 when the daily average was 46.6F. So at this rate we are on track to beat it...IF...we stay warm. Unfortunately, temps will cool down to around normal (or perhaps a little warmer than that) this weekend, before a pineapple express heat wave strikes again midweek. We will come close...but no guarantee of being number one. But we will probably be in the top ten warm Januarys in any case. My garden is starting to react--bulbs are pushing up, a chorus of bird songs is rising , and the grass seems to be growing a bit.

Today was extraordinary....strong east winds in the Puget Sound lowlands and spring-like warmth. I went running during lunch to experience it all...there were strong easterly winds, with white caps on Lake Washington. Easterlies are pretty unusual in Seattle...and today's flow was moving right up and over the mountains. As this air subsides on the western slopes there is compressional warming that gives the temps an added boost. The Seattle profiler shows this easterly flow clearly...and the warming when it revved up earlier. The strong easterly flow tonight is keeping the temperatures up--when I biked home around 6:30 PM is was balmy and mild.



Sometimes I am too myopic about the west side..so let me say that the eastern side of the mountains are megawarm too....particularly since around January 10. Don't believe me? Check out the Spokane record below. Eastern Washington is really a bowl and during the winter it typically fills up with cold, cloudy air. The Tri-Cities is no vacation spot in January! (don't email me any complains about this--I am already getting too many comments from the pro-Jim Foreman crowd). This year the cold air was scoured out and warmth and sun has been enjoyed eastside. Is this good or bad for the fruit crops?

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