Weather conditions (1 Viewer)

[SimonC]

I know this is a bit late (or early - depending on how you look at it) but if I don't ask now, I'll forget before next autumn!
Could somebody explain - preferably in plain english, with subtitles for the hard of understanding - what weather patterns I need to be looking out for, for producing the ideal "fall" conditions for autumn birding on the east coast (UK)?

If only Micheal Fish et.al. would say something like "tomorrow will be a great birding day on the north Norfolk coast, with plenty of rarities expected"

Cheers

Simon

 

[Michael Frankis]

Hi Simon,

What you need is an area of high pressure with clear skies (good setting-off weather) in Scandinavia, and an area of low pressure over the southern North Sea or the Netherlands. Winds blow anti-clockwise round low pressure, so that means east winds on the north side of the low. Low pressure also means thick cloud and rain.

So birds heading south from Scandinavia set off in good conditions, and then run into foul weather half way through the night over the southern North Sea; once in it, they can no longer keep their bearings so they just go with the wind (easier than flying against it!), and drop down exhausted on the first land they come to, which is the UK east coast.

Michael

 

[SimonC]

Thank you Michael!

I've just printed that off & will now staple it to my forehead.....or, more likely, the inside of my tripod bag!

Cheers

Simon

 

[Padraig]

That was a good reply Michael. I just wondered though whether the cetre of the low to produce easterly winds off Norfolk would more likely to be somewhere off the Scillies. I'm no weather expert so I coulkd be miles out here. I know the isobars are packed more tightly together in cyclonic than anticyclonic weather but I still reckon the centre of it all would be further south than you suggested.
But then you never said the 'centre of the low' so maybe its that I'm being a bit pedantic or even tryi :h?: ng to show off what little I know about weather charts.

Cheers,

Padraig. :h?:

 

[Bluetail]

That's a fair comment, Padraig. Since depressions move and 99% of them come from the Atlantic, perhaps it would be more accurate to say that ideally what you need is one that tracks up the English Channel.

Incidentally I strongly recommend "Birds and Weather: A Birdwatcher's Guide" by Stephen Moss (Hamlyn, 1995). Very approachably written, it includes various synoptic charts illustrating classic examples of things like southern overshooting, east-coast Bluethroat falls, autumn vagrancy from the east, winter wildfowl influxes etc, etc. Now out of print, but well worth searching out.

I've also just discovered this:
http://www.bbc.co.uk/weather/features/birds_folklore.shtml

Jason

 

[SimonC]

Thanks Jason,

If I don't try to understand Padraig's comments I think I'll be ok! (o)<

Thank's also for the book recommendation, I've been on the look out for something like that for ages - Cheers!

 

[Michael Frankis]

Hi Padraig,
A low centered on Scilly, unless it was large, wouldn't have any effect at Norfolk; if it was a large one, the winds in Norfolk would be southerly with no more than a hint of east.

Hi Jason,
The best falls are usually when a depression stalls (becomes very slow-moving) so giving a much more prolonged period of east winds on its northern side. Fast-moving depressions are good fro bringing stuff across from America, but they don't do so much for the east coast.

Michael