Joely

I'm guessing not an awful lot can take off in winds that high, is it reasonable to assume a good amount of disruption on the way (I'm due to go to JFK in the morning)

gms

It entirely depends on which direction the wind is coming from. If head-winds, then probably just some impact on the flow rate, but if they are serious cross winds then potential for much bigger impact.

T8191

JER Met saying "West to southwest gale F8 to severe gale F9".

That, combined with a very high tide, has led to a RED weather warning for flooding [and probably trees coming down and blocking roads].

KARFA

Weather report for tomorrow for Heathrow.

The last two lines are the wind noted for tomorrow morning. Tbh it seems less disruptive than Saturday as the wind is no longer coming from due south as it was yesterday but instead from 230 degrees. What this means is the wind has less crosswind component is less.

So yesterday the wind was 80 degrees off runway heading which means the crosswind component was 0.98 x wind speed (inc. gust). So when the wind speed was 40kts the crosswind component was 39.2 kts. The headwind component was only 0.17 x wind speed so 6.8kts.

Tomorrow the wind looks like it will be 40 degrees off runway heading so the crosswind component is now much less at 0.64 x wind speed, and headwind component more at 0.77 x wind speed, giving 25.6kts crosswind component and 30.8ktsheadwind component.

madfish

Karfa, your knowledge and clear explanation is most appreciated. Hopefully this means no cancellations as I have just completed online checkin for 19 people!

msm2000uk

Will BA be pro-active and announce the delays in advance (as in 6-12 hours before the flight), or do you think they will leave it until passengers arrive at LHR?

Im off to CDG tomorrow at 0840, with connecting flights to BKK...albeit on a separate ticket and PNR so can't expect BA to do anything if we are badly delayed/cancelled.

KARFA

Thanks. BotB is the real expert in the weather forecasting area so hopefully he will add/correct anything.

I think the fact there is less crosswind is helpful, but the increased headwind means slower arrivals rate. Time based spearation which is now in helps reduce that but can't completely counter the headwind effect. Whislt yesterday wasn't too bad as the Saturday schedule tends to be less tomorrow the overall effect could be a little worse as the weekday shcedule tends to be busier.

355F1

It was pretty bumpy coming into LHR at his morning on a 747.

Touchdown was fine. But the last 2-3k feet were wobbly as hell!

kanderson1965

I always find it amusing that the TV weather forecasts refer to wind speeds in mph rather than knots, which would be more useful to us flying types.

londonba2014

Moved

Joely

I flew out to BOS last Monday and it was fairly lively for the first 5 minutes certainly, sounds like I will be in for a repeat performance for my trip to JFK tomorrow!

callum9999

But TV weather forecasts are for people who would have no idea what knots means?

xenole

Has the wind changed take off direction? Normally loads of planes queuing outside Galleries First but only seen one plane taking off in the opposite direction (unless it's quiet on Sunday)

madfish

Flight radar still shows planes taking off to the west. Perhaps it is because of the time as they alternate the runways at 3pm as far as I am aware.

kanderson1965

I am not convinced that they understand windspeed in mph either. The same argument was used when temperature reports were changed from Fahrenheit to Celsius. If the argument that Celsius is an international standard scale for temperature, then knots is still the only measure of speed used wordwide.