Predicting flight reliability in bad weather

[davidjohnson6]

I sometimes find myself having to book flights at short notice (less than 5 days) on airlines with fairly small aircraft - think 19 seaters.

I'm aware at 7 am on a nice calm day in a northern European spring, all is fine, but in the middle of winter, the weather has a habit of making things sufficiently wet and windy that an airline may have to start heavily delaying or even cancelling flights. Even for highly experienced pilots, I imagine a 40+ knot crosswind with heavy rain is considered sub-optimal.

If there's a fair chance given the forecast of the weather being distinctly cr*p, I'd rather defer a trip for another day, instead of spending several wasted hours travelling to/from airport and waiting at the airport - being self employed, the cost of my wasted time is worth more than the cost of a new ticket. For clear commercial reasons which I respect, unless a hurricane is imminent, airlines are very reluctant to cancel flights a day in advance just because it might be rather windy tomorrow.

So what level of tolerance should one allow from the met forecast for a small aircraft (below 50 seats) or B737/A320 aircraft before considering a flight just ain't gonna happen reliably ?

[+TSRA]

None, unfortunately. I've been in planning before where the weather at a destination 2 hours away was reported as visual and with a good forecast. 45 minutes later with passengers all boarded and doors closed, we received notification that the weather had gone south and was now below our landing minimums with a changed forecast indicating the same. By the time we deplaned everyone and started for lunch, the weather changed again to be above landing minimums, but not great. We loaded up, got on our way and the weather changed like that the whole trip. We missed our first attempt, got in the second. The next day, same route, same weather. We went anyways and it was severe clear by the time we landed.

Point is, the weather changes too quickly over the time of any flights, even those under an hour. If airlines tried to look at trends in weather they'd end up wasting more time with cancelled flights where the weather ended up good and more missed approaches where the weather ended up not so good.

Unless the forecast is for weather conditions to exceed any AFM limitations (wind, ice, etc), we are the mercy of mother natures sense of humour.

[ExXB]

You could try looking at your flight's 'history' on Flightaware (http://de.flightaware.com). The data base in Europe is not as extensive as N. America but it can give you an idea of what happened in the past.
Not a crystal ball for the future though.

[Hartington]

I can remember sitting on the North York Moors a good few years ago waiting to dole out food to some friends who were attempting the Lyke Wake Walk. When we drove up to the rendezvous it was fog (maybe low cloud, not sure) but we started heating soup etc. 10 minutes later the fog had gone and we could see our first "client" in the far distance.

In a slightly different vein I recall a BA skipper doing one of his first 767 crossings back from the east coast and being given a rather negative weather brief for his route only to find as he crossed off his alternates as he passed them that they all had good weatehr!

[Boing7117]

You won't get much taking off nor landing with a consistent 40+ kt crosswind.

Can't speak for the bigger aircraft but the dhc8-400 has a 32kt limitation.

In all fairness though, we don't get these sort of winds regularly in the UK.

[MathFox]

David, as most of the replies have made clear, there is no sure-fire way to predict whether a flight will go or be canceled. The weather predictions a few days in advance are not good enough for that.
On the other hand I am sure that by picking days where the weather prediction says clear weather with little wind will increase your odds to actually make the trip as scheduled. Avoid days with predicted snow and/or stormy (>30kt) winds.