Predicting Seeing

[Radar]

Apart from checking links like these to monitor jet stream activity,

http://www.wunderground.com/global/Region/AU/pxJetStream.html?MR=1

http://squall.sfsu.edu/scripts/shemjetstream_model.html

is there any other way to (apart from scintillation) predict if an evening is going to be stable or not (air temp, coming storms etc)?-

Also sometimes I've noticed that the seeing is bad, but then within half an hour becomes nice and stable. Is there a way to predict the end of bad seeing?

Ray

[Asimov]

There's no way to fully predict as far as I know, but then, I'm totally over the technical aspects of predicting anything at all lol.

In my experience, there are 3 layers in the atmosphere to contend with; high mid & lower layers. The high being the jetstream itself.

If the breeze/wind in the lower 2 layers are running in the same direction you'll have greater success even if the jetstream is present. If the jetstream is NOT present; even greater success.

With the lower 2 layers 'fighting' against each other (breeze running in opposing directions) I'll give imaging a miss, jetstream present or not.

I've setup in 9/10 seeing in the States a few times. It either gets better, stays the same, or gets worse over a period of hours. I've also seen it fluctuate from 2/10 - 9/10 in a matter of seconds.

So in my mind, your either lucky or not on the night. Basically, imaging is a competition. A competition on who gets the best seeing lol..

[Kokatha man]

There's no way to fully predict as far as I know, but then, I'm totally over the technical aspects of predicting anything at all lol.

I've setup in 9/10 seeing in the States a few times. It either gets better, stays the same, or gets worse over a period of hours. I've also seen it fluctuate from 2/10 - 9/10 in a matter of seconds.

So in my mind, your either lucky or not on the night. Basically, imaging is a competition. A competition on who gets the best seeing lol..

:smiley-laughing001::smiley-laughing001::smiley-laughing001:.....too true John: it's ridiculously unpredictable a lot of the time - then there's the fortunate beggars that seem to "attract" good seeing wherever they are....!:smiley-laughing006:

[Asimov]

I used to dwell on this problem years ago "Oh golly gosh, do I setup or not!?" Then I'd look at countless weather maps, jetstream predictors etc. Then if it was supposedly crap (according to these sites) I wouldn't bother setting up.

The next day I'd then find out the sites were full of crap - & see pearler images posted by joe-blows just up the road from me in forums!

Yep I'm over it. Now I just setup if it's clear & resonably steady & cross my fingers & anything else I can cross lol.

[Kokatha man]

I used to dwell on this problem years ago "Oh golly gosh, do I setup or not!?" Then I'd look at countless weather maps, jetstream predictors etc. Then if it was supposedly crap (according to these sites) I wouldn't bother setting up.

The next day I'd then find out the sites were full of crap - & see pearler images posted by joe-blows just up the road from me in forums!

Yep I'm over it. Now I just setup if it's clear & resonably steady & cross my fingers & anything else I can cross lol.

Excatly my sentiments too - and the supposedly " more kosher" jetsream charts often change from morning prediction on any one day to their evening update.....forgetting completely about what changes happen to what they are predicting 2 or 3 days further ahead!

I've had similar experiences of supposedly crud seeing and it's turned out either okay or quite good.....and plenty of vice-versa - come to think of it, when they reckon it's gunna be good seeing it's more likely it ain't....!:smiley-laughing021:

[Asimov]

I'm still receiving emails from the clear sky clock I was registered with in the States!

I had it set so that I'd get notified if the seeing was predicted to be 7 or more.

That's the only prediction method I found to be reasonbly accurate - But we don't have the system here..

[Radar]

Thanks guys. The information about mid and lower level wind has cleared a few things up for me. Sometimes stars will twinkle when there is no jetstream (according to all reputable sources). So I guess the lower levels causes that.

I can predict local wind easily with the Australian B.o.M.


Basically, imaging is a competition. A competition on who gets the best seeing lol..

lol, interesting, but true quote mate.

Ray

[Tony]

In the States, Cleardarksky.com offers conditions for the North American Continent that I refer to every day... that having been said, I've been fooled by projected good conditions only to have then turn sour, and conditions predicted to be weak turn good. As with conventional outdoor photography, you just have to give it a go, and more often than not, it works out... but then again, my gear is heavy and takes about 30 minutes to move into place and another 30 minutes to get to imaging... so its tempting to rely on the charts sometimes...

[Rumples Riot]

Ray another good indicator is when a good high pressure sits directly over your observing position. Over the years I have seen this push jet stream and other layers out to give a nice even level of seeing. Most times if the cloud is not present you will see 7/10 or more on any given night when a high is directly over the top.

Local conditions and topography make a huge difference too, but overall it seems to be the high that dominates things.

[Radar]

Thanks for the tip mate. I will keep an eye on this. I just installed a weather station in my backyard to monitor the dew point and other factors. Life is slowly returning back to normal (after having a second son), can't wait to start hammering Joop.

Ray

[garciamartinez]

I fully understand what you mean, what I'm saying is that it is possible to judge, all the same rules. Long ago, some people that the earth is flat, long before the fire was inconceivable. The fact that we do not study things, and not see some evidence, we can not say that does not work.