Predicting FOG

[Adam.S]

Hi to all,
I have a commercial flight in a few weeks which arrives in Sydney around 8:30 am. From there I have commitments a short taxi ride form the airport that start at 10am which I must be there in time for.

At the time of booking my flight, arriving in Sydney the night before was not possible however now things have changed and I could look at this as the 'safe option', although it is not preference.

My main concern is having the morning flight delayed due to Fog.
If the flight is delayed 30-45 mins I should be ok, however delays any longer and I will be late.

I see some nights during the weather forecast on the 6pm news that "morning fog is predicted", although this forecast is often inaccurate - (understandably difficult to predict I can appreciate)


Is there any 'tool' or weather service which airlines/pilots/ATC use to predict fog 10+ hours ahead of time which has a rather high degree of accuracy?

cheers

[Philip Argy]

This is about the best you're likely to get:
http://www.airservices.gov.au/brief/html.asp?/cgi-bin/avreq?met=YSSY

[Mick F]

Adam,
Even the forecasts which we as pilots receive, can't predict fog accurately. 99% of the time it will say "PROB30" or "PROB40", which just means there is a 30 or 40% chance of whatever weather phenonema follow's that (in this case, fog). Weather is hard to predict.

Last week, I had an early morning flight to a place in the Gulf of Carpentaria. Upon reaching it, I found unforecast fog (it's generally not good when you're down at the minima of 500ft and you're still not even in it). Despite me reporting to Brisbane Centre that there WAS fog there, and plenty of it, the ammended forecast still only said "PROB30", :confused:.

So to answer your question, there is no sure fire way to know whether fog will happen or not.

Mick

[Adam P.]

Ahh fog, my favourite subject at this time of the year... lemme count the affected ports this morning: Broken Hill, Mt Gambier (no surprises there), Ceduna... there was one more, which one was it again? Some little place down south...

...oh yes, I remember now. Melbourne. Fogged in until about 0930 or so. I think that one was on the forecast last night though.

Fog affecting the airport and lasting much beyond sunrise is relatively rare in Sydney (though I seem to remember a cracker of a day in July three or four years ago when it didn't clear until about 1pm).

It's winter, fog happens. What you do depends on how much you really need to be at your meeting.

[Nigel C]

A scheduled arrival at 0830? I'd be more concerned with holding pattern delays than fog.

[Daniel G]

Even the forecasts which we as pilots receive, can't predict fog accurately. 99% of the time it will say "PROB30" or "PROB40", which just means there is a 30 or 40% chance of whatever weather phenonema follow's that (in this case, fog). Weather is hard to predict.
Mick

Interestingly on that subject, I have in the past spoken with an aviation met forecaster in regards to 'PROB30' or 'PROB40' type forecasts. As all you flying types are aware, PROB's are only ever 30 or 40% without it being flat out issued (saves the met woman/man ammending them). I was kindly advised that basically if its PROB30 it might happen, if it's a PROB40, it probably will happen...

[Jason H]

I find that most of the time it says PROB30 or PROB40, it happens anyway

[Anthony T]

Melbourne operated OK this morning in the fog.
Only 2 diversions QF from LAX & NZ from AKL? due to crew not yet authorised for CAT III ops at MEL.

[Adam P.]

...if that was OK, I'd hate to see 'bad'!!! :eek:

[Adam.S]

Thanks all for the replies, interesting and informative.
I do appreciate it.


Melbourne operated OK this morning in the fog.
Only 2 diversions QF from LAX & NZ from AKL? due to crew not yet authorised for CAT III ops at MEL.
It was today's fog in Melbourne which brought the situation to my attention.
The flight in question that I am on to Sydney in a few weeks departs from Melbourne. I have been following its on-time perfomance over the last few days whereby it has operated close to schedule, however it was delayed this morning.
It seems all passengers boarded ontime, although the flight had to sit on the tarmac for just over an hour due to the fog and traffic backlog
(or did the predicted bad weather in Sydney play its part?).

[Nigel C]

Adam, just remember Sydney only has a fog event at the airport perhaps 8 or 9 times per year, so you'd have to be terribly unlucky to cop one of these days.

[Adam.S]

^
Thanks Nigel. That was something in the back of my mind, a relatively low amount; its Melbourne which is more likely to cause problems.
A difficult balancing act; pay a lot more money to change flights, book a hotel room and arrive the night before, or save the dollars and take the 'educated' risk that fog won't occur on that particular Winter's morning.

[Adrian B]

True about Melb, but it seems things are not too bad at the moment:

ATIS ATIS YMML T 032245
APCH: EXPECT INSTRUMENT APPROACH
RWY: 16 FOR ARRS. RWY 27 FOR DEPS
OPR INFO: HIAL OPERATING
WIND: VRB 5 KTS.MAX DW 5KTS BOTH RWYS
VIS: 5000M IN BR
+ WX:
+ CLD: BKN007
+ TMP: 10
QNH: 1024