Col wrote:
"Edmund Lewis" wrote in message
oups.com...



Same here in Shrewsbury.

Until 1300BST there was not a cloud to be seen, and I thought we'd get
a 30C. From 1300-1500 a few cumulus developed, yet the sun was still
keeping us warm.
At 1600 it suddenly (and I mean suddenly) clouded over to 7/8ths cloud
cover, which looked black and threatening. I thought we were in for a
thunderstorm, but no. Just annoying cloud from nowhere which spoilt the
late afternoon. Where did this appear from? (MO radar showed similar
cloud development in a line from Cumbria down to just south of here)
Wasn't a front AFAIK, no precip, or TS.
1900 sun came out again. All in all a lovely day, except for those 3
hours of unforecast cloudy weather.

Some kind of convergence line perhaps?
I did notice on the forecast that there were light westerlies in the west and
light easterlies in the east. This combined with sea breezes and uplift
over the Pennines could have led to it. Though that's doesn't really work
for Shrewsbury!
To be fair cloud build up in the afternoon and even a very isolated shower
in Pennine areas was mentioned, so for me at least it was a very good forecast.

I wasn't surprised at all to see the cumulus flecks appear, I'd have
been more surprised *not* to have seen them. It was the way it suddenly
went totally overcast, grey and threatening in 15 minutes, with only
some brightness visible in the far W, that caught me by surprise. I and
everyone else here thought a TS was brewing, but it cleared again at
7pm.

Today it hasn't happened, it's been sunny with just a few Cu all day.

Edmund