Page 1 of 1
Undercasts and their non-uniformities
Posted: December 27th, 2023, 11:48 am
by csearle
Just arrived in Luxembourg from City. Flew mostly between two cloud layers. Couldn't help wondering how/why the undercast sported quite a few
fissures through which I sometimes fancied the ground could be seen.
Does anyone know what might explain these? The terrain below maybe? Or, maybe other cloud-busting aircraft? Both seem unlikely to me.
Thanks,
Chris
Re: Undercasts and their non-uniformities
Posted: December 27th, 2023, 12:05 pm
by tjh290633
Probably two decaying fronts, with three air masses involved. Maybe an old warm sector below, then a cold sector then another warm sector above with its own warm front giving rise to the upper cloud.
You would need to have a look at the synoptic chart for the day involved.
TJH
Re: Undercasts and their non-uniformities
Posted: December 28th, 2023, 3:58 pm
by csearle
Thanks Terry. Should have taken a photo. These things looked like the cloud was made of earthenware that had been glued together after shattering into, say, five pieces.
![Smile :)](./images/smilies/icon_e_smile.gif)
C.
Re: Undercasts and their non-uniformities
Posted: December 29th, 2023, 8:32 am
by tjh290633
csearle wrote:Thanks Terry. Should have taken a photo. These things looked like the cloud was made of earthenware that had been glued together after shattering into, say, five pieces.
![Smile :)](./images/smilies/icon_e_smile.gif)
C.
Might have been a mackerel sky, altocumulus, if that was the upper layer.
TJH
Re: Undercasts and their non-uniformities
Posted: December 29th, 2023, 9:09 am
by csearle
Well I saw these cracks below me whilst flying at FL23. I think they were through the stratus down to ground.
If I see them on the way back (unlikely) I'll take a picture. C.
Re: Undercasts and their non-uniformities
Posted: December 29th, 2023, 10:43 am
by tjh290633
csearle wrote:Well I saw these cracks below me whilst flying at FL23. I think they were through the stratus down to ground.
If I see them on the way back (unlikely) I'll take a picture. C.
If you were at FL23, then my vote would be for altocumulus as the lower level.
TJH
Re: Undercasts and their non-uniformities
Posted: December 29th, 2023, 8:30 pm
by csearle
No chance of a photo. Turns out that it's dark at 2130 CET.
![Very Happy :D](./images/smilies/icon_e_biggrin.gif)