Headwind or Tailwind - can you know in advance?

On flights from NYC to London, sometimes there is a tailwind, sometimes not. Coming back, sometimes a big headwind slows things down, sometimes... not. As it makes a big difference to the flight times (over an hour, longer to West Coast) I wondered if there is any way to know in advance?

When the captain comes on and says "we have a short flight time today" or... "we have a strong headwind today" - it would be nice to have known ahead of that point - for a slow flight one may decide to switch your itinerary at the destination, or take an upgrade for a slow one.

I appreciate its weather related, but how could you broadly find out on the morning of a flight, for example?

Isn't the accepted standard that he prevailing winds will blow west to east?

Of course, but some days there are none, some days very strong ones, etc. Be nice to know whats coming

[honey lamb]

I appreciate its weather related, but how could you broadly find out on the morning of a flight, for example?

The weather forecast. ii)

Nowadays most many TV channels (in my experience RTE and BBC) project a few days in advance.

I've never heard the jet-streams speed across the North Atlantic on the daily weather forecast, but... maybe you listen to a better one than me?

You can find the significant weather charts (search for SIGWX chart) easily enough on the internet.

These are what pilots use to help determine what sort of flight to expect (in terms of upper level winds, turbulence, icing etc.) Heights written on the chart are given in ft so FL250 would mean 25000ft.

If you print one off and then draw a straight line on the map between your start and end points you can see if you pass through any high upper level wind areas (these are the thich arrows).

You can also see if your ideal route is likely to take you through much turbulence, in which case you may notice the actual route taken will avoid these areas.

Of course they may not make much sense unless you have some meteorological knowledge and/or are a pilot!

I've never heard the jet-streams speed across the North Atlantic on the daily weather forecast, but... maybe you listen to a better one than me?

Given that in general the Jet Stream follows the same pattern across the Atlantic there is little point in mentioning it on the UK weather forecast.

However the BBC/Met Office forecasts do mention it when it changes and that change affects the UK weather.

I think it was last summer when the JS had shifted south and that's what brought us all that rain until it shifted back north and we then had sunny weather.

In the US the JS does get mentioned in day to day forecasts because it does shift over the land mass quite frequently.

The jet stream does move around a fair bit. As new Atlantic lows form and propagate eastwards the jetstreams path will be affected. For example this week the jet stream is expected to move quite a bit to the south of the UK as we find ourselves in a colder air stream.

Upper level air flow and lower level stuff are all interconnected but our media forecasts just don't go into the detail - only when it is unusual then they like to mention the JS!

As another bit of info referring to the OPs original question you can also look at 300HPa forecast wind charts online (again just search for them). This shows the jetstreams expected track and strength over the coming days so you can get an idea of how much it will interact with your flight.

Hope this helps!

You could try this website which has lots of useful charts for where the jet stream is.

http://www.turbulenceforecast.com/

The transatlantic charts are under the International section.