General Prevailing wind in the UK

[piperboy84]

What would be a best "guessstimate" of the overall prevailing wind direction in the UK ( in an area that is a flat open plain unaffected by hills etc.,) What i mean is if you were gonna designate an area of a 20 acre field as a strip is there a general rule of thumb of the highest frequency of wind direction( ie. 270,230 etc.) over say a period of year for the UK, or is this an impossible questions as you would have to study on a more localised basis. I dont see any statistics on the Met website, is there any other almanac type data source that may record this info?

[Genghis the Engineer]

About 240 degrees for most of England and eastern Scotland, a bit nearer 280 in the North West.

If you want much more accurate historical data, have a rummage around on The British Atmospheric Data Centre (http://www.badc.ac.uk)

[Gertrude the Wombat]

Look up some local airfields, and see which way their runways are pointing :)

[Jan Olieslagers]

Excuse me for trying to guess your real question.
Should you, by any chance, be planning or wondering the layout of a g/a aerodrome, you should be concerned about the typical user, who is like to be a VFR only pilot, and thus your runway should correspond with the prevailing winds IN VFR CONDITIONS.

As an illustration only: round here, which I think is not much different from round yours, prevailing winds are from the west. So that most of our a/d's and especially the bigger ones have runways like 25/07 (EBBR) 26/08 (EBOS) 29/11 (EBAW) and so on.
However private fliers have learnt that if wind is from the West, it brings such an awful lot of moisture that flying is out of the way anyway, making the western runway orientation useless. So that, in the rare cases where a choice could be made, runways are more or less NE/SW such as EBGB 01/19 or EBZW 04/22. Concurring better with most of the flyable weather.

hth,

[piperboy84]

Look up some local airfields, and see which way their runways are pointing

Most of the fields round here a former military and they got more runways than you can shake a stick at. The issue I have is I built a single strip (levelled, ploughed, drained and rolled) and its natural heading due to obstructions etc was 270. For the first month I used it the wind was right down the strip and I congratulated myself on being a right clever bast^%d. However since then the wind is more often than not from between 230 to 250. I am fixing to make a second single strip on another farm and want to get it right this time. I fly a tail-dragger and its crosswind tolerances and my xwnd capabilities leave a lot be desired. So on the new strip I wanted to see if there was any data that would allow me to squeeze the most flying days per year possible out off it and stay within my xwnd comfort zone.

[Cusco]

Don't forget that near the coast the prevailing winds are more likely to be perpendicular to the coastline for most of the summer months.....

Look at Clacton and Cromer for example.

[piperboy84]

Jan, Thanks, that makes perfect sense . I always wondered why the small primarily "VFR" fields like Oban, Coll etc, were oriented more to a SW heading than the larger fields with commercial traffic that seemed to be predominantly oriented too a westerly heading.

[The500man]

If you have a 20 acre field why not designate two or three strips crossing in the centre for all possible wind directions? Is there a reason why it has to be just one strip?

[BillieBob]

Better yet, if you have a 20 acre field, why not grade and mow the whole lot and let aircraft land into wind irrespective of it's direction, just like we used to? Rendcomb is a good example.

Failing that, the prevailing wind in the UK is south-westerly.

[piperboy84]

My newphew farms it and wants the remainder for growing tatties and barley ( its good quality Ag land) I don't want to be greedy. It would be a real pain for him ploughing and harvesting around an X or triangle shape and having to always concern himself with tracking up parts of the strip with the tractor

[Genghis the Engineer]

I can see that.

The local topography will be a significant player also, and may constrain you down certain lines.

You can do worse than wade through the petabytes of data on BADC and see if you can find some historical information for a weather station reasonably close to your proposed airfield.

If your nephew is a farmer also however, surely he has a very good feel for the prevailing wind and weather on his land?

There's another issue for me personally, landing on a 240-270/ish heading around sunset can be unpleasant and dangerous because you are looking straight into the sun and can't see a damned thing. Most times, I'd generally rather do evening landings on around a 210 heading with a crosswind but I can at-least see the runway in front of me.

G

[2high2fastagain]

Genghis, that BADC website, deserves a 'link of the week' award. I shall spend hours in there.

Genghis' point about low sun is right on the money. If there's no cloud, it can be a real pain. In the winter, I've noticed the wind tends to drop towards the end of the day, so it is much more pleasant landing in another direction. If you can persuade your nephew to let you quarter the field with two runways, then that would give you more (safe) options.

[gasax]

Rather than quarter the field you might try using two of the sides - presuming it is more 'squarish'. It does mean the fence or boundary is always going to be an issue but doesn't mess up the agriculture anything like so much.

[riverrock83]

If you want an easier to access site, see below. Select your nearest weather station, then select wind statistics. Check what period the stats are over (some might be over 10 years, others much less). It doesn't differentiate between VFR and non VFR days though:
Windfinder - Wind & weather forecast map British Isles (Great Britain, Ireland, United Kingdom) (http://www.windfinder.com/forecasts/wind_british_isles_akt.htm)

If near the coast, it probably depends as much on the time of day you do most of your flying (onshore / offshore breezes) as anything else though.

HTH
RR

[Genghis the Engineer]

If you want an easier to access site, see below. Select your nearest weather station, then select wind statistics. Check what period the stats are over (some might be over 10 years, others much less). It doesn't differentiate between VFR and non VFR days though:
Windfinder - Wind & weather forecast map British Isles (Great Britain, Ireland, United Kingdom) (http://www.windfinder.com/forecasts/wind_british_isles_akt.htm)

If near the coast, it probably depends as much on the time of day you do most of your flying (onshore / offshore breezes) as anything else though.

HTH
RR

I'd guess that's BADC data it's using, but a brilliant bit of presentation. Purely for interest, I took Yeovilton, and got...

http://chart.apis.google.com/chart?chxl=0:|N|NNE|NE|ENE|E|ESE|SE|SSE|S|SSW|SW|WSW|W|WNW|N W|NNW&chxr=1,0,11&chxt=x,y&chs=340x340&cht=r&chco=FFFFFF&chds=0,11&chd=t:2,6,6,3,4,4,5,4,6,11,7,8,7,9,7,3,2&chdl=%C2%A9+windfinder.com&chdlp=t&chls=0,4,0&chm=B,FF000082,0,0,0&chtt=Wind+dir.+distribution+Yeovilton+all+year&chts=676767,12.5

And Yeovilton's runways 09/27 and 04/22 make near perfect sense.


Similarly Edinburgh...

http://chart.apis.google.com/chart?chxl=0:|N|NNE|NE|ENE|E|ESE|SE|SSE|S|SSW|SW|WSW|W|WNW|N W|NNW&chxr=1,0,24&chxt=x,y&chs=340x340&cht=r&chco=FFFFFF&chds=0,24&chd=t:2,2,9,10,3,1,1,1,1,5,12,24,13,3,2,2,2&chdl=%C2%A9+windfinder.com&chdlp=t&chls=0,4,0&chm=B,FF000082,0,0,0&chtt=Wind+dir.+distribution+Edinburgh%20Airport+all+year&chts=676767,12.5

Main runway 06/24.


I do find it interesting that both (and a few others I think) show a significant spike the direct opposite to the normal prevailing wind. The weather gods are presumably not trying to save airport constructors some money, so why is that? I may have to go and ask a meteorologist.

G

[gasax]

I suspect some of the directionality comes from the local topography.

Edinburgh - there is a largely east west ridge line running to the south of the airfield so that would tend to force local winds into being largely parallel to it.

Yeivil I don't know - but it looks much more like the predominating more general wind directions.

I've recently been involved in some assessments around the North York moors - which have a very marked effect on the locals winds - depending whre you are in relationship to them.

[Jan Olieslagers]

Winter: continental regime, predominant wind = NE
other times: maritime regime, predominant wind = SW
A bit oversimplified, yes, I know.

And, excuse me for repeating myself, those graphs are not saying a lot, nice though they may look. What we really want to know is the direction and strength of wind AT THE TIMES WE COULD CONSIDER FLYING. No private pilot is interested in 27025G55.