Author Topic: Selective Memory  (Read 2180 times)

fefeldarsro

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Re: Selective Memory
« Reply #15 on: January 12, 2018, 09:00:02 AM »
So we should be even more selective and judge a whole year of bad weather on those 2 weeks of nice weather in September?

jingdilenma

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Re: Selective Memory
« Reply #16 on: January 13, 2018, 12:21:52 PM »
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So we should be even more selective and judge a whole year of bad weather on those 2 weeks of nice weather in September?

Right now, from the posts here, I am getting a picture of solid, unrelenting nighttime overcast since January 1st in NYNE, interrupted by two clear weeks in late September. Is that weather really what happened?

tiocartratca

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Re: Selective Memory
« Reply #17 on: January 13, 2018, 10:15:32 PM »
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So we should be even more selective and judge a whole year of bad weather on those 2 weeks of nice weather in September?

Right now, from the posts here, I am getting a picture of solid, unrelenting nighttime overcast since January 1st in NYNE, interrupted by two clear weeks in late September. Is that weather really what happened?
I don't count partly cloudy skies so but if you do, then no, we had some breaks. It was so bad I counted NEAF as part of my observing sessions. Get the picture? But brother, it sucked to be an astronomer this year. Boy, oh, boy, did it ever....

STARKID2U

junktranasop

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Re: Selective Memory
« Reply #18 on: January 17, 2018, 12:37:06 AM »
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Quote

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So we should be even more selective and judge a whole year of bad weather on those 2 weeks of nice weather in September?

Right now, from the posts here, I am getting a picture of solid, unrelenting nighttime overcast since January 1st in NYNE, interrupted by two clear weeks in late September. Is that weather really what happened?
I don't count partly cloudy skies so but if you do, then no, we had some breaks. It was so bad I counted NEAF as part of my observing sessions. Get the picture? But brother, it sucked to be an astronomer this year. Boy, oh, boy, did it ever....
I have always seen partly cloudy nights as opportunities to observe. I have always seen nights even with some Moonlight as opportunities to observe. Maybe it's a matter of perspective?

coreanoguf

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Re: Selective Memory
« Reply #19 on: January 18, 2018, 03:20:28 AM »
It depends on how you observe.,This past spell of clear skies has been great.,I've logged many hours.,but I can observe any time I want.,any night.,no obligations to anything else.,so to me this hasn't been such a terrible year.,Now I've only been observing for 9yrs. so I can't say "well 15yrs. ago blah blah" but I can say that 12 days and nights of lovely clear weather in Sept. is not the norm here in Maine.,The Local fair is almost always a wet week for the fair go'eres.,The fact that many of these clear nights were without the moon was a bonus indeed.,.,

Scott Rogers

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Re: Selective Memory
« Reply #20 on: January 20, 2018, 02:28:35 PM »
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Well, the warm weather has come and gone now. It was almost two full weeks of warm weather and clear days and nights. The Black Forest Star Party happened to coincide with this period. It was 5-6 glorious nights of clear-sky viewing! But, Tony, it did not detract from this: We in NY State did NOT get a summer. Period. And the rain and clouds were relentless in the "spring". And I suspect that most of the upper NE had the same experience. I could only get in some viewing at the Cherry Springs Star Party in the spring and even then, it rained on and off the whole time, with only partial clearing at night. No, this year was a bust, on the whole, and that is how I will remember it. A short, wet summer with a burst of warm and dry at the end, like a fireworks display. The only silver lining is that no two years are alike and next year will certainly be better than this year was. So be it and so it goes...

STARKID2U

I coach track in the spring and it was the worst weather for spring track too - not so much the temperatures, but the rain and wind.

I have this giant depression that has eroded out in my driveway and it fills in when there is rain. It never dried up the entire summer which has never happened before. Literally there were small frogs in it all summer.

prehconbubun

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Re: Selective Memory
« Reply #21 on: January 20, 2018, 09:59:31 PM »
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For the record, New York and New England have now experienced a week of almost cloud-free weather -- including the end of the last new-Moon phase -- and it is forecast to continue for most of next week, with a break for 24 hours of showers. Moreover, the transparency has ranged from good to excellent, and nighttime temperatures have been delightful throughout. All very unusual for the eastern U.S.

What do you want to bet that when people in this region look back on 2017 they will entirely forget this period, and instead bemoan how cloudy the early summer was? And those among us who are constantly harping on how much better the good old days were will take this as proof that everything is declining everywhere in every possible way.

Thus are anecdotal averages and anecdotal trends born.

Those observers who are outside on every clear night, or who at least go outside to check the weather each night will remember the stretch of clear skies. Those with more sporadic observing habits will remember "one or two" clear nights in a row and clouds for the rest of the year.
I know every day what the weather forecast is and check the sky as it gets dark ... perhaps one mitigating factor in my perception as to how bad the number of clear skies have been is that - and I haven't charted this but just noted - the full moon time seems to correspond with many of the clear nights that we have had.

So for example, in a given month maybe a few consecutive clear nights have slipped in, but those nights have mostly corresponded with a full moon which obviously limits the deep sky observing.

My friend with the 6" Lunt APO has the added constraint that due to his work schedule he can only get out on Friday and Saturday nights. In a year already rich with cloudy nights that has severely limited his chances.

For my part there have been numerous times this past year when the ~ 2 weeks when the Moon is not a problem for observing in the evening sky have passed with not a single clear night.

And the other thing is how variable it is locally. Literally one night I was at my parents house at sunset and it was crystal clear. I traveled the 7 miles from their house to mine and it was overcast. So you get these strange local variations. I see it all the time - if I just lived 10 miles this way or that instead of clouds I would have clear skies or the reverse.

Weather around here is just strange. During one of the storms in August my dad called to tell me that it was pouring looking out the back of his house but ... He walked the 30 feet to the front of his house and it was dry - not a drop of rain. This went on for 10 minutes. How does that even happen?

jumphindnore

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Re: Selective Memory
« Reply #22 on: January 21, 2018, 02:54:40 AM »
I think the memory is always selective.. We remember the unusual event rather than the typical event. If Tony chooses to remember the clear skies in September, those are good memories.

I remember this winter and spring as being cloudy with very limited opportunities but looking back at my notes, it was only February when things were really bad and I was only able to get out for 8 nights. The other months were typical for me, 14-17 nights. I rarely get in more than that, what with the moon, something of a social life and clouds.

Jon

Charlie Carpenter

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Re: Selective Memory
« Reply #23 on: January 23, 2018, 01:51:28 AM »
I have 2-3 clear nights a month on average, usually just one at a time, when the weather systems happen to all keep the clouds away simultaneously. In summer there's more but then solar is the sole option up here.

Let's check. Next clear night may happen 8 October. Clear weather then in the forecast for about 12 hours. So it may be then, or some other night. I like to check probabilities, for example Meteoblue have about ten different forecasts, they can vary very much. Anyhow, even if it would be cloudy with a 90% probability every singular night there still is one clear night on average during a 10 day period.

Having a whole month without even one clear night would maybe make me complain a bit. Haven't happened yet during 2017. Somehow it suits me to be out 0-1 times a week. Or maybe I have made it suit? You can't fight windmills, and maybe better not wanting to.

And studying the moon is natural, feels pragmatic! Every clear night is an option. Good transparency and seeing is a possible icing of the cake, but not a necessity, like cloud free skies are.

Cloudy Nights we are here : )

Davione Boone

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Re: Selective Memory
« Reply #24 on: January 23, 2018, 03:17:12 AM »
Just as you say, Jon, memory alone can be quite selective and hardly worth posting about when discussing a question involving accuracy in numbers. But just as you also point out, those of us who follow more in the way of a regimented observing scheme resulting in detailed nightly records can look back to our actual written entries and see concrete evidence of how good, or bad, any month, year, or decade really was. Thereby you have actual statistical evidence to refer too. If those records extend back decades it becomes possible to document trends clearly.

In my own case the number of nights with recorded observing sessions should actually be bias in favor of the last 10 to 15 years, because I was retired and had every clear night available to me. Yet, the number of clear observing nights has instead continued to decline! I have even been resorting to using party cloudy nights and those with far less than favorable conditions recently, nights I would have passed on years ago. Had I not, this spring I would have seen a couple of months probably without any recorded observing sessions at all, something I've never encountered previously since joining the AAVSO back in 1963!

BrooksObs

gairiloocon

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Re: Selective Memory
« Reply #25 on: January 23, 2018, 08:02:24 AM »
I wonder how much all that above ground nuclear testing during the period from ~1945 through ~1960-something affected the weather patterns you old timers enjoyed, or for that matter, how much it affect the weather patterns we see today.

Ken Kamkoff

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Re: Selective Memory
« Reply #26 on: January 23, 2018, 09:50:15 AM »
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I wonder how much all that above ground nuclear testing during the period from ~1945 through ~1960-something affected the weather patterns you old timers enjoyed, or for that matter, how much it affect the weather patterns we see today.


I tend to doubt that above ground nuclear testing had any measurable affect on the weather, certainly nothing that I can recall seeing evidence of. I would mention however that very recently I made a long post to the AAVSO forum regarding weather changes and VS observing in which I made note of a discussion I had with my mentor many many years ago (the late 1960's) about the number of clear nights perhaps declining. He had begun his variable star observing career back about 1940 and had remained one of AAVSO's top observers ever since. He remarked that he had clearly noted a slow but progressive decline in the number of clear nights in the Northeast between then and the 1960's!!! Now that's downright scary to consider!

BrooksObs

senbevekek

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Re: Selective Memory
« Reply #27 on: January 23, 2018, 09:57:11 AM »
I did have some great Jupiter nights late spring/early summer this year on nights where the transparency was horrible but the sky was extremely steady. Maxed out my refractor (275x) on at least two occations, and that rarely happens on extremely transparent nights around here...

Bob

barlaliblo

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Re: Selective Memory
« Reply #28 on: January 23, 2018, 03:27:50 PM »
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I don't know of a good source of data for nighttime cloudiness over the past decades. It would be great if such a thing existed. I think there are good records of cloudiness during the day in many regions - but not so much for the night.

Does anyone know of a good source of nighttime cloudiness measurements done in a systematic manner over the past, say - 50 years, for some location?

Professional observatories should have that - but they tend to be on mountain tops and in areas with clear skies in the first place.

I hear people in both northern and southern hemispheres saying that the skies are cloudier than they used to be. But is there any systematically taken data to back it?

Observing logs don't really count unless a log is taken every hour of every night.

Frank


This subject comes up on occasion, and at least the answer for Flagstaff, AZ is yes. Brian Skiff has been recording cloudiness data since the late 1970's. While there are many in the Southwest U.S. and California who are convinced that cloudiness has become worse, there is actually no such trend. The annual and nightly summaries may be found here:

http://www2.lowell.e...ata/clouds.html

The plot of the annual data below ("photometric" + "partial" nights) looks pretty flat. Note that here in the best astronomy climate in the country, only slightly better than one night in three is clear.I can't speak for New England, but at least in my region, the notion that the weather is degrading is indeed another case of pessimistic, selective memory. As I age, I notice that my contemporaries tend to remember many aspects of their past as being better better than they really were.

Tom


Eric Ayyagari

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Re: Selective Memory
« Reply #29 on: January 25, 2018, 07:56:00 PM »
Certainly there is some of that, "the older i get the betterI (or) it was" perhaps, but this is data that I don't feel has really been collected much on an 'eyeball vetted' basis for a lot of places in the country in a way us amature hobbyistshave easy access to. I know it is keptI think for some airports that have a NOAA pipe, but is most important ways it becomes unimportant outside the moment. Pilots and observatories just want to know what the weather is like now, and what the immediate conditions / expectations are. Data from past years not terribly relevant. I know a few years ago i was looking about on the web searching for what places or cities are the most cloudy or cloud bound, and was really surprised at the results. Trying to determine how the data was compiled it seems it was mostly from pilot / airport data. So the data sets were highly constrained. At the time I was looking for the data to help with the "if I moved..." scenario.

An interesting blog here...

Not unexpected that my city is listed as 4th worst.