27 replies to this topic

[Gschnettler]

There are plenty of maps showing light pollution, but I’m having trouble finding one that shows the best seeing.

I’ve been bookmarking various AirBnb and VRBO cabins to rent in dark parts of the country. But I would hate to actually rent one and travel there only to find that the seeing is poor.

I know that seeing varies from night to night, and even hour to hour, so I’m just looking for an “average seeing conditions” type map.

Do you know if such a map is available?

[ShaulaB]

Find websites for astronomy clubs near the locations of your cabins. Send emails to contact people asking their opinions.

 

How to find clubs? Try these sites:

 

    The Night Sky Network Club Finder.
    Sky & Telescope Magazine Club Finder.
    Astronomy Magazine Club Finder.
    Go-Astronomy.

[T1R2]

Well if anyone is reading this tonight in C Arkansas...why, you should be out with your scope, its a 300, 400, 500x+ night, just had my 127mm refractor on Saturn at 330x but since the image got a little dim I dropped it back down to 254x and I'm still happy.

 

One thing we can do is check where the jet stream is in your area, that will give you some general idea of the seeing, next, most charts like the Clear Sky Charts will have daily updates on smoke, clouds etc.

 

Just google your city location followed by clear sky chart...example: Cincinnati Ohio Clear Sky Chart

 

https://www.cleardar...nnatiOHkey.html

[Tony Flanders]

There are plenty of maps showing light pollution, but I’m having trouble finding one that shows the best seeing.

I’ve been bookmarking various AirBnb and VRBO cabins to rent in dark parts of the country. But I would hate to actually rent one and travel there only to find that the seeing is poor.

I know that seeing varies from night to night, and even hour to hour, so I’m just looking for an “average seeing conditions” type map.

Do you know if such a map is available?

I'm reasonably sure that no such map exists -- at least not one accessible by civilians. It's just conceivable that the various nations' sky-satellite agencies have such maps, because the problem of seeing fine details on Earth when looking down from space is much the same as the problem of seeing fine details in space when looking up from Earth.

 

The problems are two-fold. First, there's no obvious automated way to collect such data -- unless as I hypothesize spy satellites can do so. Second, seeing frequently varies on very small scales; on the top of a mountain traveling 100 yards from the windward slope to the lee slope can change the seeing from excellent to poor.

 

So your best bet is probably anecdotal data. Ask around -- on Cloudy Nights or elsewhere -- what the typical seeing is like at your chosen locations. If you're restricting yourself to the United States, then on average southerly locations (away from the jet stream) are likely to be best. The California and Florida coasts are both famous for their good seeing, but neither is famous for its dark skies.

[bonsaiguy]

I don't know of any maps like that, but these web sites may help you get an idea of what the current and upcoming viewing conditions will be like at your prospective observing locations.

 

https://www.meteoblu...-states_5392323

 

https://www.cleardarksky.com/csk/

[Gschnettler]

That’s odd that no seeing maps seem to exist.

If that’s the case then I’m looking for more information like this: “The California and Florida coasts are both famous for their good seeing”.

I’m willing to travel 1000 miles in any direction from Cincinnati, Ohio in order to get to some good sites. I know where it’s dark (e.g. Cherry Springs, PA; Spruce Knob, WV). I’m trying to supplement the well known light pollution info with some seeing info.

Given a 1000 mile radius circle I think it’d be tedious to attempt to look at sites like clear dark sky one location at a time. Or to attempt to identity and contact local astronomy clubs across that large of an area.

In the absence of maps, where can I find info on which parts of the country typically have good seeing (so I know where to go) and bad seeing (so I know where to avoid going)?

We now know that Florida and California coasts are generally good. Are there any other good spots?

Also, are there differences in time of year? For example, is seeing generally better in the winter?

[Keith Rivich]

That’s odd that no seeing maps seem to exist.

If that’s the case then I’m looking for more information like this: “The California and Florida coasts are both famous for their good seeing”.

I’m willing to travel 1000 miles in any direction from Cincinnati, Ohio in order to get to some good sites. I know where it’s dark (e.g. Cherry Springs, PA; Spruce Knob, WV). I’m trying to supplement the well known light pollution info with some seeing info.

Given a 1000 mile radius circle I think it’d be tedious to attempt to look at sites like clear dark sky one location at a time. Or to attempt to identity and contact local astronomy clubs across that large of an area.

In the absence of maps, where can I find info on which parts of the country typically have good seeing (so I know where to go) and bad seeing (so I know where to avoid going)?

We now know that Florida and California coasts are generally good. Are there any other good spots?

Also, are there differences in time of year? For example, is seeing generally better in the winter?

I observe around 100 miles from the Gulf of Mexico. Good seeing is more the rule then the exception. Bad seeing usually follows a cold front taking a few days to settle down. 

[Napp]

Check maps of the jet stream.  Wherever it tends to hang out there will likely be poor seeing.

[Gschnettler]

I’m looking around at a few jet stream maps.
This one is interesting. If you watch the animation it appears that the whole USA is affected by the jet stream. Which if true means that I don’t know where to travel in order to get good seeing

https://weatherstree...nd-forecast.php

[Napp]

The problem you are facing is that seeing forecasts are iffy at best.  Check the Environment Canada Astronomy Forecasts (weather.gc.ca/astro/index_e.html).  It happens to be the source for many astronomy oriented weather apps.  It has probably the best seeing forecast available because you can watch the changes in the maps at a large scale.  However, there are a couple of weaknesses of forecasts.  First, weather is an extremely complex system that the models are at best incomplete.  Second, forecasts are for broad areas and not microclimates of particular locations.  I look at various forecasts before setting up in my driveway or departing to my dark sky site.  Then I see what actually occurs which can differ greatly from the forecast.  On top of that seeing can vary dramatically throughout the night. There are a couple of areas that that you mentioned in your first post that tend to have good or better seeing quite often.  What southern Florida and the coast of California around San Diego have in common is laminar flow of air over the sea.  Neither is affected that often by the jet stream.  If you want to have the best chance of good seeing plan a longer trip to one of them.

[T1R2]

The jet stream is tricky  as it moves, it also stays in place for a while too, which can be good or bad, the south / s. east usually has good to great seeing in the summer months, my average night outside Little Rock supports 180-200x on average several nights a week  I haven't logged how many but I'd say at least 250 nights a yr,  and with at least a 250x or over on at least 75 -100

 

You want to look for lazy high pressure domes when its hot and muggy with droughts, and no wind in sight and the jet stream is way north of you or way south. Even so still, if the jet stream is north of you then you'll be looking to the south at Saturn so you might get lucky,

[Jon Isaacs]

Dark skies and excellent seeing are not often companions.. People like to live in places where the seeing is very good, they're near the ocean, the winds are light.

 

In San Diego, along the coast tends to have quite good seeing through it has not been a great year yet.  

 

The nearby mountains are much darker but tend to suffer from more average or even substandard seeing.  

 

So for me, it's doubles and the planets from the coast, DSOs from the high desert.

 

Jon

[Alan D. Whitman]

 

 

You want to look for lazy high pressure domes when its hot and muggy with droughts, and no wind in sight and the jet stream is way north of you or way south.

A broad upper ridge on the 500mb charts will normally provide fine seeing even at my northern latitude of 49 North. A massive upper high (which is rare) will provide exceptional seeing even at this latitude.

 

Very local poor seeing will be caused by downslope drainage winds (katabatic winds) at night even under (especially under) a massive upper high. If you are on the peak, there will not be any downslope drainage winds. Other observers at the same star party who are a few hundred feet downslope may not experience the fine seeing available on the peak. Cold air flowing downhill at night follows the terrain just like that other fluid that you are more used to (running water) would. So, for example, my backyard observatory is downhill of ridges, but there are no ravines uphill of it directing turbulent cold air drainage into my backyard. The next yard over has a ravine uphill of it so I would not have bought that yard which is only 80 feet away. I have never observed from my neighbour's yard, but I'm pretty sure that the seeing in that yard would routinely be poor on nights when I am enjoying exceptional seeing.

 

Alan Whitman

Retired Meteorologist / Contributing Editor Sky&Telescope

[T1R2]

Its another 300, 400, 500x+ night in C, Arkansas,  it would be nice to have a thread dedicated to seeing reports , that way someone from your area might check into the thread to see if anyone from their area is viewing and if its worth taking their scope out for planetary 

[T1R2]

And just like that the seeing deteriorated and I'm stuck at 180x, I guess it could be worse.

[jrkorman]

There are plenty of maps showing light pollution, but I’m having trouble finding one that shows the best seeing.

I’ve been bookmarking various AirBnb and VRBO cabins to rent in dark parts of the country. But I would hate to actually rent one and travel there only to find that the seeing is poor.

I know that seeing varies from night to night, and even hour to hour, so I’m just looking for an “average seeing conditions” type map.

Do you know if such a map is available?

I'm retired USAF weather. If you think forecasting rain a few hours "downstream" is hard, that would be child's play compared to trying to forecast seeing. My $0.02US.

Edited by jrkorman, 30 September 2023 - 12:33 AM.

[JOEinCO]

And just like that the seeing deteriorated and I'm stuck at 180x, I guess it could be worse.

 

Yes it could.  

[T1R2]

Yes it could.  

It was a false alarm...I was able to push it back up to 254x a little bit later, but then Saturn went behind the trees and I turned the scope to Jupiter which was rising higher and higher and watched the GRS transit, but I liked the view of Jup better at 183x because its lighter color got washed out easier at 254x.

[Gschnettler]

alright, it seems that a "seeing map" isn't going to be possible. 

 

But, is there a place to get more anecdotal data?  For example, it's seems that it might be common knowledge that there is good seeing at the coasts of Florida and California. 

 

Is anywhere else in the USA known to have good seeing?

 

 

 

 

 

[Napp]

I recommend attending the Winter Star Party in the Florida Keys in February.  The added bonus is a break from winter for you.  You won't find a cheaper way to spend a week in the Keys in the winter unless you have a relative or friend there who will let you use their couch.

[jrkorman]

alright, it seems that a "seeing map" isn't going to be possible. 

 

But, is there a place to get more anecdotal data?  For example, it's seems that it might be common knowledge that there is good seeing at the coasts of Florida and California. 

 

Is anywhere else in the USA known to have good seeing?

Big Bend National Park in the Winter season. Very dark skies, the weather tends to be pleasant, and storm systems tend to be further north.

[T1R2]

A broad upper ridge on the 500mb charts will normally provide fine seeing even at my northern latitude of 49 North. A massive upper high (which is rare) will provide exceptional seeing even at this latitude.

 

Very local poor seeing will be caused by downslope drainage winds (katabatic winds) at night even under (especially under) a massive upper high. If you are on the peak, there will not be any downslope drainage winds. Other observers at the same star party who are a few hundred feet downslope may not experience the fine seeing available on the peak. Cold air flowing downhill at night follows the terrain just like that other fluid that you are more used to (running water) would. So, for example, my backyard observatory is downhill of ridges, but there are no ravines uphill of it directing turbulent cold air drainage into my backyard. The next yard over has a ravine uphill of it so I would not have bought that yard which is only 80 feet away. I have never observed from my neighbour's yard, but I'm pretty sure that the seeing in that yard would routinely be poor on nights when I am enjoying exceptional seeing.

 

Alan Whitman

Retired Meteorologist / Contributing Editor Sky&Telescope

Yeah, seeing is not looking so great for us, down-right terrible the next week or so, but the clarity may be great for low/ med power if you have clear skies.

 

The 500mb map shows how deep the trough will go  https://www.youtube....?v=pcLZbUoelLk 

[graz]

There are plenty of maps showing light pollution, but I’m having trouble finding one that shows the best seeing.

I’ve been bookmarking various AirBnb and VRBO cabins to rent in dark parts of the country. But I would hate to actually rent one and travel there only to find that the seeing is poor.

I know that seeing varies from night to night, and even hour to hour, so I’m just looking for an “average seeing conditions” type map.

Do you know if such a map is available?

Not a map, rather a forecastfor for many locations including yours:

https://www.meteoblu...-states_4508722
 

Edited by graz, 17 October 2023 - 02:47 PM.

[daveb2022]

I find forecasts often contradict each other. Also, from my backyard, the seeing over the night might change rapidly. But I can sum up my observing sites I have frequented over the years. My home in the CA central valley provides much more good seeing days than poor. I might not get exceptional seeing, but I often reach a Pickering 8 level. On the other end of it, I rarely see a Pickering 4 level and the average is around  P-6 or 7. I have observed a lot from up top Glacier Point in Yosemite. Other than cloud cover, on all the trips I've taken there, I've never had anything other than exceptional seeing. Perhaps the rising air currents stabilize things??? I also have a spot in the Sierra's that supply very good skies most of the time. It's also a spot with rising air currents from a large valley below. Another spot close to the crest is usually very poor on average.

 

I would never trust a app forecast over talking with those who use a particular area often to observe from.

 

I don't know if it's timing, but the last couple weeks of September (at my home) were horrible transparency wise. The worst in 2 years, but I also had an unbelievably great season from Sept 2022 up until a few weeks ago. Now it's back to normal. Last night and the night before I had seeing so good that I could easily see Saturn's Cassini division, but by the time Jupiter was within view, it wasn't good at all.

[Cpk133]

Yeah, seeing is not looking so great for us, down-right terrible the next week or so, but the clarity may be great for low/ med power if you have clear skies.

 

The 500mb map shows how deep the trough will go  https://www.youtube....?v=pcLZbUoelLk 

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