Sorry Q; I mean, since you said: If the wind direction of the flat side of the approaching low has any easterly component it will undercut.
You then said it was a pure southerly so it would be close. I was hoping there was the tiniest easterly component in the southerly-biased flow on the E side of the low you showed. So I was asking if there was any chance of an undercut as a result of this.
I also wondered if, being that close, it would be more of a struggle between the (hoped-for) undercutting low and the high, as it wasn't such a clear victory for the undercutting low. I wondered, in association with this, whether that might lead to the undercutting process being delayed at all, leading to a slower process.
You have now said very small easterly components succeed, making me wonder it some more.
Originally Posted by: Bertwhistle