Lunar phases and cloud: any link?

[Euan]

Maybe I'm being paranoid, but it seems like every time I get a decent clear spell it coincides with a bright moon?

..oh well just as well some clever person invented narrowband imaging

[brianb]

Being diagnosed "paranoid" doesn't mean there's no-one after you....

I'm convinced the weather pattern does often change at around the time of new moon or full moon, more often than it does with the moon about half phase. But the change can go either way. Just hoping that the forthcoming Full Moon will shift the depression that's been sitting over the UK for the last 10 days back to Iceland where it should be ...

[Peter Drew]

We used to keep a record of full Moon/clear sky correlation and there was a very significant percentage of this happening. Never seen any authoritative meteorological explanation for this.

[hunterknox]

Are there such a things as atmospheric tides?

[James]

I keep some records regarding clear skies and the phase of the moon - they're at home somewhere and I have a pot on SGL somewhere but the gist of it is that I in Taunton seem to get far more clear skies at full moon than new moon. One other thing I've noticed is that in the last 35 months there's always been a clear night when the moons phase is around 60-65%... except for the last two months.

I doubt it's coincidence but I also doubt the clear skies are actually related to the phase - there's probably another cause that happens to have a monthly cycle...

James

[Talitha]

I'd read somewhere that there's a valid explanation for the phenomenon of clear Full Moon skies, not only in the UK but here in the US as well... might have been on a meteorological sight, can't recall. But as an avid lunar observer, i can say that there seem to be just as many clouds when i'd like to catch some deep sky as there are when i'd like to see Luna.

Very interesting, James.. i've noticed more clear nights during a 75 to 80 percent waxing gibbous Moon than any other time. One thing's for sure, though... the seeing's never too good in my locale no matter what the lunar phase is.

[oceanheadted]

Euan,

good post. I noticed that full moon often seems to be clear, but just thought it was coincidence/I was deluding myself....

cheers

Alan

[kev]

Yes there are atmospheric tides, as the atmosphere is fliud just like water, but they dont do much. As for the weather at full moon... hmm yes of late ive noiced that too.

Mind you living on the east coast what I really need for a clear sky is a gentle westerly, as the moors are to the west and Scarbro has a local weather system where any small amount of cloud biulds on the moor and leaves the town clear. Ive seen it c5C colder just a mile inland than in my garden! Easterlies - such as we are reported to be gettig next week are a mixed bag here. Sometime it can be really clear - and also really cold, but other times in winter we get low cloud / snow.

PS I live on a 1 in 5 hill, have seen the rubbish cart skid all the way down the hill!!!

[brianb]

Ive seen it c5C colder just a mile inland than in my garden!

Yes, this is the problem with a coastal location, I have the same issue - when the wind is parallel to the coast the temp can rise & fall continuously by several degrees, which plays merry hell with the seeing as the scope never gets a chance to cool anywhere near ambient, and when it's cooler than the dewpoint (moist wind off the sea) you could easily drown in the condensation. Best conditions with a light wind either directly onshore (relatively warm but moist, temperature steady) or directly offshore (cooler & usually drier but sometimes bringing fog, temperature slowly dropping through the night). Strong winds almost invariably bring bad seeing irrespective of direction.

[Euan]

Well, weeks of cloud and now were coming up to a full moon... OH LOOK WHAT A SURPRISE!