Altocumulus Lenticularis?

[Evening thunder]

Not quite sure where to put this, but about a week ago I noticed what I think are Altocumulus Lenticularis clouds to my east. Not as stunning as the pictures you can see on Google but noticeable to weather people.

This occurred in a westerly or NW'erly airflow I think, and stayed over the same spot for an hour or two until after the sun set and it became dark. If these are Lenticular clouds I find it interesting that these must have formed from the lift over hills that reach just 250m in elevation at a maximum. Would be interested in thoughts?

Edited May 28, 2011 by Stormmad26

[Summer of 95]

One of the many effects the hills nearby have on the climate here is Lenticular clouds, we get absolutely LOADS of them. In the last 2 weeks with the incessant westerlies there have been few days when I haven't spotted at least one or two. I've often seen them below a layer of Altostratus or Cirrostratus as well as against blue sky. Sometimes they are so large they seem to form a layer of medium-level cloud.

Most of them appear to have formed over the Welsh hills (the 800m Berwyns are about 30 miles NW of here), but I've also clocked the odd one swirling above the Clees and Stretton hills.

Nice for photographers but they can be a real pain when you want unbroken sunshine!

[Evening thunder]

Thanks for that that's interesting, they seem to be more common than I thought. I did think a while ago you usually needed mountains with decent height for them. I have seen what looked like small/shallow versions around here before in fact this evening I saw what looked like a couple of shallow ones, but one was to my south over the channel!

As the air flows 'through' them as they tend to stay over the same spot I can imagine they'd be pretty frustrating if you're under the shadow of one!

[Summer of 95]

Thanks for that that's interesting, they seem to be more common than I thought. I did think a while ago you usually needed mountains with decent height for them. I have seen what looked like small/shallow versions around here before in fact this evening I saw what looked like a couple of shallow ones, but one was to my south over the channel!

As the air flows 'through' them as they tend to stay over the same spot I can imagine they'd be pretty frustrating if you're under the shadow of one!

Dartmoor (where I suspect yours originate from) is certainly high enough if the Shropshire and mid-Wales hills can produce them. But there's so many hills to the W, S and SW (and even NE) of here that we rarely get only one or two, sometimes they can merge into layers of Altostratus (at least that's what it looks like, suppose it's technically still Altocumulus!) and block the sun for hours at a time- we saw this a few times last week.

They do make for good photos when you see individual ones swirling over a hilltop though.