Weather

[Mike-Bracknell]

Apols for the not amazingly technical nature of this question, but where would a non-pilot be able to get a decently accurate weather report for an impending flight?

Also, in people's experiences, how long before weather reports change at cruising altitudes? (i.e. can I leave it a day or so before flying and still have a *fair* representation of the likely weather, or is it so changeable up there that you could never tell one hour to the next?)

Finally, how would one read a weather report such as the ones so often quoted here? (i.e. what format does a pilot weather report take?)

Thanks,
Mike.

[Dit]

Met Office: Weather services for aviation (http://www.metoffice.gov.uk/aviation/ga.html) is a good start, it gives TAFs and Metar (and has a decode page to help you understand them) as well as giving UK and Europe Low level winds and weather charts.

[tubby linton]

The website below is probably more user friendly than the met office:
Weather : London-Gatwick England (http://en.allmetsat.com/metar-taf/france.php?icao=EGKK)

[One Outsider]

The question you forgot to ask is; "would I understand the information given"?

Weather information for aviation is formatted for people trained in the subject. You might not gain any correct insight, without someone trained in the interpretation of said information.

[Mike-Bracknell]

The question you forgot to ask is; "would I understand the information given"?

well, I did ask..

Finally, how would one read a weather report such as the ones so often quoted here?

..so i'm hoping some kind person comes along and imparts wisdom ;)

[bookworm]

Also, in people's experiences, how long before weather reports change at cruising altitudes? (i.e. can I leave it a day or so before flying and still have a *fair* representation of the likely weather, or is it so changeable up there that you could never tell one hour to the next?)

The weather at cruising altitudes is generally forecast (I presume you mean forecast rather than report) based on models initiated 24 hours before the valid time. E.g. the forecast for 1200 Tuesday will be based on a model run initiated 1200 Monday and will usually be available by 1800 Monday. It isn't usually updated. The output is usually graphical -- a significant weather chart indicating areas of CBs, CAT and jetstreams.

The airport weather is usually relevant only at the very beginning and end of a flight. It is forecast up to 30 hours in advance for major airports.

[ProfChrisReed]

Mike-Bracknell,

It depends on the type of flight.

If you're talking about ain airline flight, the distances travelled mean that the aircraft will transit so many weather systems that I can't suggest where to look.

If you're interested in a light aircraft flight (some kind of trial lesson, given the non-pilot audience) then my experience from several years wrestling with weather forecasting for gliding suggest the following:

1. The forecast the day before is usually pretty close - good enough to tell if (a) it's flyable and (b) roughly what kind of weather can be expected. All you can get from forecasts further ahead is a trend, unless you know what you're looking for.

2. For a non-pilot I'd recommend the Met Office site - Met Office: UK: forecast weather (http://www.metoffice.gov.uk/weather/uk/uk_forecast_weather.html) (click on the region where you intend to fly). This gives some idea whether it is likely to rain (solid rain = bad, but if showers you can fly in between, unless thunderstorms are forecast in which case it might be foolish to fly), how windy it will be (anything over 15-20 mph you might ring the airfield on the day to check whether it's too windy - wind direction is important, but a non-pilot won't know enough to know the difficult directions). This will give a general idea whether it's likely to be a pleasant flying day.

3. From that site you can work out how bumpy the day is likely to be. If you select the Wind tab, it gives wind speed in a white circle, and gust speed in a red box. If the gust speed is around 3x the wind speed, this means thermals and thus bumpy conditions. Good for glider pilots, less good for a first flight.

4. What's missing is cloudbase - if the picture shows sun and cloud, this is unlikely to be a problem. If you see white or grey clouds with no sun symbol, the cloud might be too low for a pleasant flight. The RASP site RASPtable (http://rasp.inn.leedsmet.ac.uk/RASPtable.html), used extensively by glider pilots, lets you check forecast cloudbase among other parameters. I'd say anything less than 2,000ft is likely to be less than good for a first flight, though it might be perfectly flyable.

5. The final element is visibility - on some days it's like flying in the steam over a bowl of soup, and not great if you're flying for fun. XCWeather Wind Map - Britain Forecast (http://www.xcweather.co.uk/GB/forecast) can give you this - anything less than about 5k visibility takes away some of the fun of a first flight.

Hope this is of some use.

[Mike-Bracknell]

Thanks Bookworm and Chris.

I'm generally interested in weather from an airline perspective, since i'm a bad-flying SLF and a SITT (Speccy I.T. Tw@t), this combination means I have a thirst for knowledge in order not to be caught out by turbulence (which I hate with a passion).

Hence the question (which if we expand it a bit more) is of how to understand whether i'm likely to have a decent flight or not, from the weather reports available.

(and also as a side-note, how to read those weather reports the pilots post here which look like orders at a fast food restaurant for the uninitiated!)

[napolean]

Turbulence unfortunately is probably one of the most difficult areas to predict accurately. High level charts will show areas of predicted moderate to severe turbulence. I have often flown in these areas and had smooth rides. On other days areas showing no forecast turbulence have occasionally had some. Wind speed aloft does not necessarily correlate with turbulence levels.

Regards