Land Breeze Showers? Expert answers appreciated!

[Graham Easterling]

It is the norm for showers to develop along the spine of Cornwall (mainly Camborne eastwards) or along the spine of the Lizard if the gradient wind tends northerly (as was the case yesterday) during unstable conditions.

However, on a few occasions you get a line of slow moving showers off the north and or south coasts developing around sunrise, and then gradually starting to move as the temperature rises. A good example this morning.

07:15

By 08:15 just starting to move, but not much.

Is a land breeze one of the factors involved? The SST is around 14C, the temperature dropped to 8C in Penzance around dawn. THe wind did appear to be offshore all around the coast of Cornwall around 8pm. (S at Camborne & Newquay, SE at Lands End, NE at Culdrose & up at Plymouth)

The line of showers now extends well to the SW of Lands End, suggesting there is much more to it, but I think the land breeze might have been a factor adding an extra boost.

No convergence line on the 6am UKMO charts.

Graham

Penzance

[Len W]

I doubt it was initiated by a land breeze Graham.

The unstable air stream is ripe for shower development during the day inland

as shown by the current radar pic.

But look at the line of rain over the sea to the the south of Cornwall at 1235.

Convergence lines seem to form in all sorts of places.

Len

Wembury