Severe Storms hit Melbourne suspending services 24-6-2014

 
  bevans Site Admin

Location: Melbourne, Australia
Many lines suspended due to storms in Melbourne. Hurstbridge line blocked as is belgrave

Sponsored advertisement

  bevans Site Admin

Location: Melbourne, Australia
southbank flooded!



and

  bevans Site Admin

Location: Melbourne, Australia
  X'Trapolis-904M Deputy Commissioner

Location: Melbourne
Belgrave


Suspended • 1 hour agoBetween Bayswater & Belgrave due to a tree that has fallen across rail tracks at Upper Ferntree Gully. Replacement buses are in operation. Please listen for announcements.


Train services have resumed between Carrum and Moorabbin after an earlier issue with fallen trees. Customers may experience delays to 15 minutes as we get our trains and drivers back in position.




Between Macleod & Eltham due to a tree that has fallen across rail tracks at Macleod. Buses replacements may take some time to get in position, please listen out to announcements

Train services have resumed between Ringwood & Lilydale after an earlier issue with a fallen tree across rail tracks at Croydon. Customers may experience delays to 10 minutes as we get trains and drivers back into position.



Delays up to 15 minutes due to a tree that fell across rail tracks at Hampton. Trains need to travel at reduced speed until the area is fully cleared.

The line has reopened between Bell & South Morang after a fallen tree was removed from across rail tracks at Ruthven. Delays to 15 minutes as we recover. Please listen for announcements.


Between Frankston – Stony Point due to a tree fallen across rail tracks in the Tyabb area. Replacement buses will be in operation. Please listen for announcements.

Customers may experience delays to 10 minutes in both directions as a knock effect from the signal issue on the Werribee and Sunbury lines.
  X'Trapolis-904M Deputy Commissioner

Location: Melbourne
and power is gone on 40% of the jemena network aswell
but not affecting train lines
  bevans Site Admin

Location: Melbourne, Australia
  X'Trapolis-904M Deputy Commissioner

Location: Melbourne
Edit the IMG Tag was For a Instagram video But RP Does not Support That
Format
  X'Trapolis-904M Deputy Commissioner

Location: Melbourne
  X'Trapolis-904M Deputy Commissioner

Location: Melbourne
  DalyWaters Chief Commissioner

Is this the first "once in a hundred years" weather event for this year?
  Valvegear Oliver Bullied, CME

Location: Norda Fittazroy
Is this the first "once in a hundred years" weather event for this year?
DalyWaters

I think so, but there'll be another one pretty soon. That will then be superseded by "the worst bushfire season for many years."
  712M Chief Commissioner

Caulfield - Oakleigh was also suspended in the afternoon peak due to a vehicle being hit by a train.
  raudteejaam Train Controller

Is this the first "once in a hundred years" weather event for this year?
DalyWaters

Just to clarify, when people say a "one in one hundred year storm", what it actually means is there is a 1% chance in a given year that the storm/flood/whatever will occur. That's why it's possible to have such events multiple times a year or in successive years, it's a mathematical formula, not a guaranteed weather cycle.

My SES crew are still mopping up today, though we have just cleared our last task. We had a tree leaning against was either a power staunchion or signal gantry on Tuesday that required a lot of back and forth with Metro, who eventually took responsibility for clearing it. I assume they did before it created any problems.
  Valvegear Oliver Bullied, CME

Location: Norda Fittazroy
Just to clarify, when people say a "one in one hundred year storm", what it actually means is there is a 1% chance in a given year that the storm/flood/whatever will occur. That's why it's possible to have such events multiple times a year or in successive years, it's a mathematical formula, not a guaranteed weather cycle.
raudteejaam

Without wishing to appear rude, I do not believe your definition. The words mean what they say, i.e one in a hundred years. That is plain English. Without going into details, I have had this debate with idiot Consulting Engineers, and they believe they are designing for one event, and one only, and it will occur only once in a hundred years. The concept is, of course, nonsense, but enough of them believe it.
  xxxxlbear Token Booking Clerk

Location: Geelong
The term 'one-in-a-hundred-year' weather event is really a misnomer as we don't have weather records that go back more than 100 years or so, give or take a few years. Just because an event happened yesterday, or whenever, but hasn't happened for 100 years doesn't necessarily mean that it only happens every 100 years on average. We might have just been lucky that it hasn't happened more regularly in the last century. Mother Nature is her own boss Smile
  bevans Site Admin

Location: Melbourne, Australia
From the weather reports today it would seem we have another storm with high winds heading our way.
  SAR520SMBH Train Controller

It's on it's way bevans. The wind is starting to pick up here in Adelaide. Forcasting rain to hit around early arvo, gail force winds up to 100kph, hail and possible thunderstorms. Brace yourselves over there guys.
  bevans Site Admin

Location: Melbourne, Australia
It's on it's way bevans. The wind is starting to pick up here in Adelaide. Forcasting rain to hit around early arvo, gail force winds up to 100kph, hail and possible thunderstorms. Brace yourselves over there guys.
SAR520SMBH


lots of false pics from Bunbury.  The wind is picking up.
  ZH836301 Chief Commissioner

Location: BleakCity
Horrid wind today, got blown all over the highway on the bike.
  raudteejaam Train Controller

Without wishing to appear rude, I do not believe your definition. The words mean what they say, i.e one in a hundred years. That is plain English. Without going into details, I have had this debate with idiot Consulting Engineers, and they believe they are designing for one event, and one only, and it will occur only once in a hundred years. The concept is, of course, nonsense, but enough of them believe it.
Valvegear

The Bureau of Meteorology backs me up. You can choose to believe them as the experts or not. The phrase is just a phrase, the actual maths and science behind it really means there is a 1% chance that it will occur in a given year. I'm not going to comment further, but you can read the link below and see for yourself.

I'll quote the clearest part for you:
It is important to note that an ARI (average recurrence interval) of, say, 100 years does not mean that the event will only occur once every 100 years. In fact, for each and every year, there is a 1% chance (a 1 in 100 chance) that the event (in this example, 48.2 mm in 1 hour) will be equalled or exceeded (once or more than once).



http://www.bom.gov.au/water/designRainfalls/rainfallEvents/why100years.shtml
  Valvegear Oliver Bullied, CME

Location: Norda Fittazroy
Thanks raudteejam.  As I said, the definition I have been subjected to for many years, by idiot Consulting Engineers, is the one I have had to deal with. Obviously, it is a definition in fairly common usage. If I may say it again, the concept is nonsense, but they believe it.  

However, using proper English, "one in a hundred years" cannot possibly mean, "a one percent chance in any given year."  The two expressions are mutually contradictory. Once in approximately 36,500 days is blindingly obviously considerably less than the one percent definition you quoted. I do not dispute the Bureau of Meteorology's expertise, but I do not understand the reluctance of people/firms/ writers/ Departments to use clear, concise, accurate English.
  ZH836301 Chief Commissioner

Location: BleakCity
It's common terminology - a one in two chance in a coin toss does not mean you will get one head in two flips.

If you understood statistics, you would realise it is impossible to express figures in the way you desire - I'm not having a go or expecting that you should, as it's university level stuff, but there is a reason things aren't as simple as you would naively expect.

One in 100 years is an expectation value - the average number of events expected over a 100 year period will be one. The expectation value is simple for discrete events like flipping a coin, for example, the expectation value for heads of 100 flips is 50. However, to deduce such things for continuous events you need to use calculus, and it gets messy.

In this case the probability for a one in T year event occurring once (or importantly, more) over n years is:

P = 1 - (1-1/T)^n

Ie. over 100 years the probability it occurs once or more is 63.40%, and thus for it not occurring 36.6%. Over one year the probability of at least one event is 1%, with a 99% chance it doesn't occur. The messiness comes from the need to consider infinitesimal time (ie. the probability of the event occurring over a infinitely small time frame) which allows for the possibility of more than one event in a given year. There is also a static assumption, which explains why 1:100 year events tend to be clustered.

Consider simply a 1:5 yr event, ignoring for simplicity the possibility of more than one event a year (ie. simply stating that the event either does or does not occur in a given year):

The probability of it occurring in a year is 1/5, and not 4/5, then the probability of N events in five years is:

Pr(N) = A(N) x (4/5)^(5-N) x (1/5)^N where N is the number of possibilities of the order of the event occuring, ie.

For 5 years, there are 2^5=32 possibilities of how the events are ordered

N=0: Pr=1x[(4/5)^(5)][(1/5)^0]=32.769%
N=1: Pr=5x[(4/5)^(4)][(1/5)^1]=40.96%
N=2: Pr=10x[(4/5)^(3)][(1/5)^2]=20.48%
N=3: Pr=10x[(4/5)^(2)][(1/5)^3]=5.12%
N=4: Pr=5x[(4/5)^(1)][(1/5)^4]=0.64%
N=5: Pr=1x[(4/5)^(0)][(1/5)^5]=0.032%

The expected number of events is the probability of that number of events by that number of events:

Ie. Expected value = ~0.33*0+0.41*1+0.20*2+0.051*3+0.0064*4+0.00032*5 = 1

Note that 2 events has a probability of 20%, and three of 5%, so not completely unexpected. For completion we really need to consider multiple events in a year which will change the probabilities slightly (since we have possibilities of N=6,7,8...) but isn't really necessary for low probability events, and won't change the expected value.

However, using proper English, "one in a hundred years" cannot possibly mean, "a one percent chance in any given year."  The two expressions are mutually contradictory.
Valvegear

As you can see, a probability of 1% in a year gives an expected 1 event in 100 years - they mean the same thing.
  justapassenger Minister for Railways

Thanks raudteejam.  As I said, the definition I have been subjected to for many years, by idiot Consulting Engineers, is the one I have had to deal with. Obviously, it is a definition in fairly common usage. If I may say it again, the concept is nonsense, but they believe it.  

However, using proper English, "one in a hundred years" cannot possibly mean, "a one percent chance in any given year."  The two expressions are mutually contradictory. Once in approximately 36,500 days is blindingly obviously considerably less than the one percent definition you quoted. I do not dispute the Bureau of Meteorology's expertise, but I do not understand the reluctance of people/firms/ writers/ Departments to use clear, concise, accurate English.
"Valvegear"
That is a case for people being taught to understand and use the accepted terminology correctly, not for abandoning said accepted terminology which works in favour of something else which will come with its own issues.
  Valvegear Oliver Bullied, CME

Location: Norda Fittazroy
A quotation, attributed to Disraeli, said, "There are three types of lies;- lies, damned lies, and statistics!" Laughing

And, for the benefit of the condescending ZH836301, I did "university level stuff" but it didn't include statistics; what I did it was more useful and practical. Nor do I believe that I'm naive.

My comments about correct English stand. The purpose of language is to communicate, and the expression under discussion obviously fails to do this with a large number of the public whom it is meant to inform. This "large number" includes people who did "university level stuff".

And, justapassenger, there is no need to educate the public into the meaning of a very obscure and poorly-worded statistic. Just express it simply and easily. That's why we have a language.
  ZH836301 Chief Commissioner

Location: BleakCity
But that's how you express it - one in a hundred years literally means a 1% chance in a given year.

What do you want them to say, that means the same thing?

(And again, I wasn't having ago, naive is a common term in science).

Sponsored advertisement

Subscribers: bevans, xxxxlbear

Display from:   

Quick Reply

We've disabled Quick Reply for this thread as it was last updated more than six months ago.