"Keith (Southend)" wrote in message
...
Will Hand wrote:
"James Brown" wrote in message
...
Is it a warm outlier I wonder - the encroaching warmer air from the SW
seems to at least temporarily make it through the block....

Not so cheers!
--
James Brown

Yep a marked warm outlier. Ignore it.

Will

I do admire your confidence Will :-)


Thanks keith, but it's based on a lot of experience and knowledge. In these
situations, once a block becomes established with an anchoring low to the
south of the anticyclone, what that does is two things, it helps to deflect
the westerly jet and feeds negative potential vorticity from the south into
the high - both help to maintain the block. The low to the south, by itself
will not normally break down a block. It sometimes does happen but rarely.
Looking more closely it seems that that run wanted to collapse our present
high quickly before the northern retrogressed high built, this is at odds
with the ensemble mean. What it might be signalling though is the
possibility of some organised rain/snow in the SW as the low pressure
weakness brushes northwestwards.

Will
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