Mirabile dictu! The jet stream is apparently moving north, at last, and an anticyclone is set to move in from the Azores. This may just be in the nick of time to save the 2012 Purple Emperor season from an apocalyptic start.
At the moment, we do not know whether the butterfly has managed to hold back from emerging, and is simply late; or hasn't held back, and is out in appallingly low numbers. We'll know by the end of Sunday. It may be a mixed picture. It is likely that it's still not out properly in many sites, including Fermyn Woods, Northants (though I fear it may have collapsed there).
At present it appears that males are only well out in some of the early-emerging sites (in Hants, Middx, Oxon & Surrey), and that only one female has been seen so far (Chiddingfold Forest, last Sunday). It also appears that numbers are very low away from the primary male territories in the best locations, and even in those local epicentres numbers seem to be at best modest.
The butterfly is likely to be at peak season (maximum numbers) this weekend at most of its sites, so that will be the time to take to the woods - so, skip the big family wedding, birthday, anniversary, sell the children into slavery and, in the words of IRP Heslop, the founder of the Purple Passion: 'To the woods - without breakfast!'