Friday, September 9, 2011

Onshore Push

Update 7 AM Tuesday...the push was fairly strong last night---and still quite breezy this morning. The satellite picture below shows low clouds pushing to the crest of the Cascades. Want sun today? Simply go over the passes. A few miles more and you will be in bright sun. But remember that places like Ellensberg will get hammered by strong NW winds today...and golf at Suncadia will be, lets say, a challenge. (and see the new video link at the end of this blog)




My wind chimes are ringing right now and the trees are starting to sway as the wind increases. Such behavior after a warm day means only one thing...an onshore push has started.

Temperatures rose into the low 70s over much of the western lowlands today, but as we enjoyed the warmth an upper level disturbance has been approaching and the difference in pressure between the coast and interior has been rising. These changes are producing an onshore surge of marine air that will bring a substantial cooling tomorrow (by at least 10F) and the return of low clouds in the morning.

Meteorologists follow the pressure differences very carefully during such events. North Bend, Oregon minus Sea-Tac is one that is popular. I prefer Hoquiam minus Seattle. As shown below, this pressure different grew from near zero to around 2.6 mb today....enough for a modest push. For a strong one you look for 3.5 to 4 mb. The times below are in GMT (18 is 10 AM, 00 is 5 PM)


Here is the predicted upper level chart for 2 AM this morning. You can see the trough--centered over Vancouver Island-- moving towards us. Onshore pushes with northwesterly flow tend to be be on the weak side.


Perhaps the best way to see a push in progress is by looking at the wind and temperatures from the Seattle Sand Point profiler (below). Time is on the x-axis and height (in meters) on the y axis. If you can read the blue wind vectors, you can see that the winds are now from the southwest in the lowest 1000 meters (roughly 3000 ft) and increasing....a good sign of an onshore push.



And the low clouds offshore have thickened and started to push in! (see satellite picture below)

So get your sweater out for tomorrow...highs will be in the lower 60s, clouds will dominate, and there even could be some light sprinkles. By the afternoon there could be some cloud breaks and maybe a bit of sun.

Onshore pushes are the main forecast problems during Northwest summers---some call it our version of air conditioning.

Finally, a key point is that we are in a very different pattern from the last few weeks--it may not be hot, but endless days of clouds and rain are NOT in the forecast.

KUOW: Several listeners delivered the petition with nearly 5000 signatories to KUOW today and talked with their program manager Jeff Hansen. KCPQ-TV (Channel 13) covered it....and should be on at 10 PM. Here is the segment on KCPQ:

http://www.q13fox.com/videobeta/?watchId=38b0cbf5-7207-405f-8369-01a9125fab7b


KCPQ also gave me some time to talk about what I would have said on KUOW if I had been allowed. I am working on a detailed blog about my interactions with KUOW and particularly their reactions during the past few weeks. I really think KUOW has serious issues and I will try to analyze them in this work.

Climategate


Several of you have asked me during the past few weeks to comment on Climategate--the emails stolen from the University of East Anglia dealing with global warming issues. I will do so here, but I want to go beyond that situation to some of my own personal observations derived my own experiences doing climate-related research.

Let me start with my bottom line points:

Were some of the climategate emails inappropriate? Yes
Have some scientists exaggerated the implications of human caused global warming? Yes.
Are many global warming deniers unreasonable and expressing opinions that are not based in facts or rational thought? Yes.
Is the basic science of climate change now in question because of the climategate emails? No.
Has the whole business gotten too political? Surely.
Are scientists human and sometimes doing things out based on human emotion or group think? Yes.

Climategate emails: I read through more than a hundred of them...particularly the ones that have gotten big attention. These scientists were in circle the wagons mode. Clearly, they felt under pressure, if not threatened, by the global warming (GW) skeptics, and discussed ways of denying the critics information requested through Freedom of Information inquiries. They scientists talked about erasing emails, and not publishing in journals they felt were printing materials they disagreed with. Web sites like "Climate Audit" has become dirty words to some. (I personally love "Climate Audit"!). All of this was inappropriate.

In the famous "trick" email the east Anglia emails talk about replacing the proxy tree ring records with instrumental records for the past several decades (because the tree ring records disagreed with what the instrumental records were saying)--instead of just showing those records and noting the difficulty. Not quite open. Is there any major technical cover up evident in the emails?...not that I could see. Denier and skeptic types are claiming that these emails undermine the whole global warming business...and they are completely wrong about that. But there are some general issues we should talk about.

There is an almost tribal separation going on today between the scientific community and their "allies" (generally of a liberal persuasion) and the denier and critic crowd (many of them of a conservative bent). The denier folks have become angry, with conspiracy theories and accusations of far-left agendas. Whenever there is an article on climate change in newspapers, these people leaves large numbers of online comments. And few of them are well informed about the science. And there is a lot of misinformation on the "pro" global warming side as well. Scientists, unaccustomed to being on the firing line, have gotten defensive--and the emails from climategate really document this attitude.

This defensiveness has now gotten unhealthy for both the science and society. Scientists who attempt to publish material indicating that global warming due to manmade causes is not evident or weak, or who doubt the severity of the problem, are not treated well by some. I have had some first-hand experience with this. I am known as somewhat of a skeptic regarding global warming effects in the NW--although I do believe that greenhouse gases are a serious problem in the long-run. A group of us noted that the snowpack in the Cascades was NOT rapidly melting away, in contrast to some publications by some local climate scientists and publicized by Mayor Nickels. The reaction was intense. One of my colleagues, Mark Albright, who was the first to notice the lack of snowpack loss was fired as associate State Climatologist and the media went wild...we called it Snowpackgate...and it got national attention. I was told in the hallways to keep quiet about it...the denier types would take advantage of it!

We then wrote a paper on the subject (the main contributor being Mark Stoelinga) and submitted it to the Journal of Climate. I have published a lot of papers in my life (roughly 100) and I never had problems like we had with this paper. Very biased associate editor and some reviewers. Four review cycles and it was about to be turned down, until we appealed to the editor, who proved fair and reasonable. This paper has now been accepted for publication, but it really revealed to me the bias in the system. Here is the paper if you are interested:

http://ams.allenpress.com/perlserv/?request=get-pdf&doi=10.1175%2F2009JCLI2911.1
Poor papers with significant technical problems, but reflecting the "official" line, get published easily, while papers indicating the global warming is weaker or delayed, go through hurdle after hurdle.

I have heard case after case of similar treatment...so this is no anomaly.

The media tends to publish all kind of threatening predictions about global warming without really researching them. A good example is that suggestion that heavier precipitation will fall in the NW under GW...or is already happening. There is no evidence for this, but it gets repeated over and over again. On the other hand the denier types point to every cold wave or the fact there has NOT been a lot of warming in the last 5-10 years (which doesn't mean anything). And the glaciers! Some of the melting may well be due to man-forced warming...but the melting started early in the last century before CO2 effects were significant.

Another problem is that uncertainty of our climate predictions are often not clearly expressed in various publications--even semi-official ones put out by climate impacts groups of various types. It is sobering to note that the uncertainty in climate predictions has not declined over the past decades. Our models are much better now than thirty years ago, but key aspects of the modeling systems...like how they simulate clouds... are not as realistic as we would like...and this is very important for climate change work. I think people sense there is more uncertainty in the predictions than the official outlets tell them...and that may be part of the fuel of denier rage. The essential physics of warming is quite solid and well understood, but the details...like how clouds will react...are still under investigation.

So perhaps I have been confusing....but the bottom line is that this issue has been completely politicized and confused with both sides using problematic information at times....did this have to happen? If Gore hadn't taken up the mantle of stopping global warming, would things have been better? Can Climategate lead to a better approach and attitude among all parties?

Wednesday, September 7, 2011

Large Diurnal Temperature Range

An interesting aspect of the current weather regime is the large diurnal (daily) temperature range--the difference in temperature between the daily highs and lows.  At a number of Northwest locations we have seen highs in the 80s and 90s, while temperature have plummeted at night into the lower 50s and even some 40s, with some dropping into the 30s.   I am talking about surface air temperatures here, measured at roughly 2 meters. Some good examples:

Baker, Oregon--high of 90 and a low of 39F:  a diurnal range of 51F!
Olympia,WA--high of 85 and low of 44:  range of 41F

Or consider the Turnbull climate reference network site near Spokane that had  a 51 deg temperature range today with a low of  36 and a high of 87 on Tuesday.  What is really amazing is the range of surface (ground) temperature that on Tuesday jumped from 32 F to 114 F (82F!!) on Tuesday.  You read that right....from frost on the ground to 114F in one day.   That will crack some rocks!

 Here are graphs of temperature for the last two weeks--all of which show the huge range.  First, Sea-Tac, then Pasco, and finally Spokane.  All have a much greater range than normal.
So why such a big range?  Hint:  we often observe such big daily swings during late summer and early fall.

We start with fairly warm aloft and the sun being still fairly strong....that allows warming.
We have weak offshore flow aloft...that keeps the low clouds and marine influence at bay.
We have clear or nearly clear skies...that allows good infrared radiational cooling to space--and thus good temperature falls at night.
And nights are getting longer--that gives more time for nighttime cooling.  And the relatively equal time for heating and cooling at this time of the year is helpful

Put this all together and you get one big temperature range.  During the winter the range is far less in general, particularly because the cloud cover reduces heating during the day and infrared cooling at night.



Now for the controversial part of this blog.   There seems to be some difference in opinion whether a large temperature range is good for viniculture.   Does a big range help or hurt the quality of grapes used in wine-making?  Some online sources claim that such a range is good since it has the effect of producing high acid and high sugar content as the grapes' exposure to sunlight increases the ripening qualities while the sudden drop in temperature at night preserves the balance of natural acids in the grape.  Others, like the book by Gladstone, claims that a narrow temperature range is good.  Any wine experts read this blog?  What is the correct story?  I have always found the meteorology of wine making fascinating...and will climate change make eastern Washington wines even better?  Perhaps in another blog.