Pacific Northwest warmer drier winter

[xrp]

Wrong. Remove 2012 and the trend line is statistically flat. With 2012 in it may be too; the confidence interval for the slope was not reported and the line may have been free hand.

Until you present your credentials so I can compare your experience and expertise vs a Chief Meteorologist, I'll side with the Chief Meteorologist.

[drm]

Wrong. Remove 2012 and the trend line is statistically flat. With 2012 in it may be too; the confidence interval for the slope was not reported and the line may have been free hand.

Until you present your credentials so I can compare your experience and expertise vs a Chief Meteorologist, I'll side with the Chief Meteorologist.

And if you remove 2005, the trend line might be steeper. Not sure how you can justify one more than the other.

As Mark Nelson said in that post, we would need to see if that trend holds for more than the one single Snotel to really say more. My _guess_ is that for higher altitudes it might hold, but that the meltout day would be earlier at lower altitudes, with a cutoff somewhere between 4000 and 5000 feet. That's been my experience. I might even spend some time to get those figures from a few other Snotels in the area, though there aren't very many as high as 5400'. It would probably take just a 5 minutes per site to get that data.

[retired jerry]

yeah, seemed like snowfall last year was much below normal below 5000 feet, but normal above

you could have one snowstorm that happened to be when the freezing level was 5000 feet

[raven]

Among other things xrp,, you confuse the study of weather with the study of cllimate. They are different disciplines, with many weathermen climate change deniers while few academic climatologists are.

As to the trend line, I have taught that stuff. Have a primer:
http://en.wikipedia.org/wiki/Trend_estimation

Note the discussion on testing the significance of the slope. If one observation is an outlier near the end of a series, the data cannot be trusted because the calculation formula weights end observations more than ones near the middle of the distribution.

[drm]

One thing that gets lost in discussions of temps is nighttime temps. I think that Portland set a record this summer for the number of nights that were 60 or more, even even with the recent rains and cooler days that are closer to average or even a bit below, the nights have stayed well above average. Official records for whether it has been or will be warmer than average aren't based only on daytime highs, they take the temperature many times per day and average them up (maybe weathercrazy can clarify this for us?) so if the current trend of average days and warm nights continues, it still will be counted as warmer than average overall.

[retired jerry]

Warmer nights helps my tomatoes, peppers, and cantelopes to ripen.

Increased CO2 in atmosphere reduces the amount of radiation back to space which keeps it warmer at night. The plot of number of nights per year greater than 60 degrees has steadily increased the last few decades, corresponding to increased CO2 levels.

This is from KPTV, a month ago, there's actually a few more for 2014 making it bigger than the previous record, 2013.

Warmer nights will also result in fewer bugs killed. We may find that bugs that used to be killed over winter, will now be a problem the next year, like those pine beatles that kill all those pine trees on the East side.

[mcds]

Warmer nights will also result in fewer bugs killed. We may find that bugs that used to be killed over winter, will now be a problem the next year, like those pine beatles that kill all those pine trees on the East side.

Yet another reason to see about getting decent snows here.

[miah66]

So either the trend is more snow during the snow season or lower temperatures during/after snow season delaying the melt out.

Another way to interpret that graph is that it could also be showing a "shift" of the seasons to start and end later than historically thought, not that we are seeing any type of increase in snowpack.

I will admit that this last year seemed different from other recent years in that there was hardly ANY snow below 5000' while above there was "normal" amounts.

Hardly any above 5000' even until after New Years, coinciding w/ a possible "shift"?

Jerry, that graph you posted is pretty interesting...er, alarming!

[drm]

It's also important to remember that relatively late meltout days do not correspond with heavy snowpacks. It could either mean the snow arrived late and/or the spring was cool, both of which have happened in recent years (but not the last 2).