On Tuesday, July 3, 2018 at 9:14:48 AM UTC+1, Graham Easterling wrote:
A very unstable day yesterday with a fair bit of cloud (which made a real change!) including sizeable Cb from late morning.

There was quite sizeable surf yesterday for the 1st time for week. I went out to Sennen (it was plenty big enough for me) and there was some interesting weather.

10:30
F3 offshore E wind sunshine, 23C or so.

11:00
A feature heading in from the east backed the wind, and together with a sea breeze influence it became a distinctly F4-5 alongshore NNE. Strong enough to create white horses & whip the top of the breaking waves. At the same time this air (now 20-21C or or so on the beach) came up against air near 25C just inland, and within minutes quite large CU had formed a mile or so inland.

12:00 The sea breeze pulse died & the wind veered E. The band of Cu & Cb passed overhead and there were a few large drops before the sun came out and the temperature rapidly rose.

During the afternoon, the sea breeze against a now generally E flow caused convergence along the north coast. A series of heavy showers ran westwards near the north coast, with some thunder. Little rain onshore.

All fell calm in the evening and it was very muggy. 22C @ 21:30.

Endlessly interesting, the weather & sea.

Graham
Penzance (Yesterdays Max 25.8C)

From Peter Lea-Cox, Umborne

It looks as if there was a steep temperature gradient in this part of the country yesterday. I see from Colin Youngs' report, Yeovilton was at 28.1C; here, we managed 24C and Nick, only 20C.