Spring migration 2012 has been interesting this year and although April has been quiet it has given an opportunity to experience big falls from in the first two days in May from the backup. Here's a summary of the key spring arrival dates so far.

March: Different to last year with migrants coming in later. My first fall came on 23rd March when 60+ Chiffchaff were recorded in the Weston area.

Crown copyright published by the Met Office 2012

April: Dominated by lower than average temperatures but despite this I did record a fall on 14th April

Crown copyright published by the Met Office 2012

Towards the end of the month the jet stream moved over the UK causing high winds and heavy rain. Low pressure at the months end finally moved west out to into the atlantic and again a warm southerly wind flow brought warmer temperatures to the UK from central Europe.

Crown copyright published by the Met Office 2012

On 1st and 2nd May large numbers of migrants came into the UK including hirundines, Swifts, Wheatears, Whinchats, Wood Warblers, flava wagtails and Terns. As the low moved farther out into the atlantic a southerly air flow across the bay of biscay brought birds to the western side of the country bringing waders and a good count of Golden Orioles.

Crown copyright published by the Met Office 2012

Note:
On 1st May 2012 I spent the morning on my local patch in a band heavy rain from a Warm Front moving northwards from Central Europe. The humidity was at 92% and there were no birds in the bushes and no birds on the move. Around late morning the weather started to clear and a trickle of Swallows soon became a full blown heavy passage involving many thousands flying through at ground level. It soon became apparent that these birds were following the trailing edge of this Warm Front which only had a very narrow window of opportunity as a short time later the birds altitude became higher and higher and then migration stopped altogether leaving several hundred in its wake static and aerial feeding.