On Thu, 20 Jul 2017 16:08:28 +0100, NY wrote:

"James Wilkinson Sword" wrote in message
news
What do you believe weather forecasters mean when they say "40% chance of
rain"?

1) It will rain for 40% of the day.
2) There's a 40% chance it will rain at some point.

I googled it and apparently it depends on the forecaster? 1) and 2) are
completely different meanings.

Given that it includes the word "chance" (ie probability) I'd interpret it
as the second meaning: if (hypothetically) you replayed the day many times
(Groundhog Day!) then approx 40% of the occurrences of the day would have
some rain.

Which is of no use to me whatsoever. Pouring with rain all day is nothing like spitting for half an hour. Yet they don't distinguish between the two. There should be a measurement where 0% means no rain at all, and 100% means rain all day.

--
Love is complicated machinery.
But sometimes all you need is a good screw to fix it.

On Thu, 20 Jul 2017 19:36:28 +0100, Gary Woods wrote:

On Thu, 20 Jul 2017 11:46:10 GMT, lid (AnthonyL)
wrote:

Yesterday Accuweather MinuteCast was showing no rain for at least
120mins

I must confess that when I saw the OP, I had two thoughts;
"An obvious troll, considering the entity posting is new, and posted
to two unrelated groups, one of which is troll fodder."
"Typical broadcast weather type, who really wants to be....a
lumberjack!"

(now that song will be running around in my head all day).

Gardening and DIY are 100% related to weather.

And I'm not a new entity. I've asked about 4 gardening questions in the gardening group over the last year, and I'm in the DIY group a lot.

--
Dopeler effect (n): The tendency of stupid ideas to seem smarter when they come at you rapidly.

On Thu, 20 Jul 2017 20:29:24 +0100, Jim S wrote:

On Thu, 20 Jul 2017 12:13:43 +0100, James Wilkinson Sword wrote:

What do you believe weather forecasters mean when they say "40% chance of rain"?

1) It will rain for 40% of the day.
2) There's a 40% chance it will rain at some point.

I googled it and apparently it depends on the forecaster? 1) and 2) are completely different meanings.

Unless there is high pressure stuck over us you can go to 7 UK forecast
sites and get seven different percentages or timings. They all claim to get
their information from the Met Office. I don't believe that all seven have
in-house meteorologists so who makes it up?

If I've been in the same place for 12 hours, and am going to be there for another 12, my watch's barometer is a better guide than the internet forecasts. It takes a reading every minute, so I get a graph of the next 12 hours ish. It doesn't say exactly what the weather'll do, but it's a very accurate guide that it'll get worse or better throughout the day.

--
"I've never claimed to be anything more than a simple person" - Ronald Tompkins, circa 2013.

On Thu, 20 Jul 2017 13:30:39 +0100, Martin wrote:

On Thu, 20 Jul 2017 11:46:10 GMT, lid (AnthonyL) wrote:

On Thu, 20 Jul 2017 12:22:20 +0100, Ash Burton
wrote:

On 20/07/2017 12:13, James Wilkinson Sword wrote:
What do you believe weather forecasters mean when they say "40% chance
of rain"?

1) It will rain for 40% of the day.
2) There's a 40% chance it will rain at some point.

I googled it and apparently it depends on the forecaster? 1) and 2) are
completely different meanings.

I think it means 2

Yesterday Accuweather MinuteCast was showing no rain for at least
120mins - I only looked at the site because it was raining and I
hadn't noticed a forecast for it.

Meteox showed no thunderstorms within about 50 miles of us, when we were in a
thunderstorm.

I've seen the Met Office get yesterday's forecast wrong!

--
If breasts had no nipples, they'd be pointless.

On Thu, 20 Jul 2017 13:20:28 +0100, Asha Santon wrote:

On 2017-07-20 11:58:05 +0000, James Wilkinson Sword said:

On Thu, 20 Jul 2017 12:44:54 +0100, Asha Santon wrote:

On 2017-07-20 11:13:43 +0000, James Wilkinson Sword said:

What do you believe weather forecasters mean when they say "40% chance
of rain"?

1) It will rain for 40% of the day.
2) There's a 40% chance it will rain at some point.

I googled it and apparently it depends on the forecaster? 1) and 2)
are completely different meanings.

It means there is a 40% chance that it will rain in the area to which
the forecast applies and during the period (often a day) specified.

It never means (1) and does not depend on the forecaster and is not a
matter of belief. Nor, happily, does it depend on google.

So it's utterly useless then? 40% chance of rain could mean there's a
40% chance I'll get a light shower for half an hour at some point, or
it could mean there's a 40% chance it will bucket down all day. They
should estimate the AMOUNT of rain that is going to fall, eg so many mm.

No, not useless. Some forecast services offer the probability for each
hour of the day which is more than sufficient.
It has happened on occasion that I have looked out of my front window
and it has been raining while out of the rear window it has been sunny
and dry. There is no way for a forecast to be that precise and 50%
chance of rain would be a perfect forecast for that.
Unless it is an unusual event, there is no way to predict the amount of
rain which will fall on any given occasion. That is why they don't do
it.

If the risk of rain is say 90% then a forecaster may well say it 'will'
rain but with a island weather, it is seldom so easy.

All forecasts are verbalised accounts of probabilities (or risks) of
events happening and that is all there is. The science does not exist,
and probably never will, to accurately predict wat are virtually random
events.

Surely they can make a reasonable guess as to how much rain will fall throughout the day. That would be far more useful. Like:
"Thursday will be spitting on and off for about 3 hours throughout the day" or
"Thursday will probably have a couple of heavy showers lasting 30 minutes each."

--
More people in the UK are injured by standing on upturned mains plugs than by electric shocks.

James Wilkinson Sword wrote

What do you believe weather forecasters
mean when they say "40% chance of rain"?

I know that they mean.

1) It will rain for 40% of the day.

Nope. Ours has both that daily number and a break down in 3 hour
blocks with that 40% appearing on at least one of the 3 hour blocks.

2) There's a 40% chance it will rain at some point.

Yep.

I googled it and apparently it depends on the forecaster?

Not here it doesn't.

1) and 2) are completely different meanings.

Sure.

"James Wilkinson Sword" wrote in message
news
On Thu, 20 Jul 2017 12:22:20 +0100, Ash Burton
wrote:

On 20/07/2017 12:13, James Wilkinson Sword wrote:
What do you believe weather forecasters mean when they say "40% chance
of rain"?

1) It will rain for 40% of the day.
2) There's a 40% chance it will rain at some point.

I googled it and apparently it depends on the forecaster? 1) and 2) are
completely different meanings.

I think it means 2

So pretty useless then.

Nope.

I have no idea if it will be for 20 minutes or the entire day.

You do when the forecaster has enough of a clue to have
an hourly or 3 hourly breakdown too like ours does.

James Wilkinson Sword wrote:
On Thu, 20 Jul 2017 16:08:28 +0100, NY wrote:

"James Wilkinson Sword" wrote in message
news
What do you believe weather forecasters mean when they say "40%
chance of rain"?

1) It will rain for 40% of the day.
2) There's a 40% chance it will rain at some point.

I googled it and apparently it depends on the forecaster? 1) and
2) are completely different meanings.

Given that it includes the word "chance" (ie probability) I'd
interpret it as the second meaning: if (hypothetically) you replayed
the day many times (Groundhog Day!) then approx 40% of the
occurrences of the day would have some rain.

Which is of no use to me whatsoever. Pouring with rain all day is
nothing like spitting for half an hour. Yet they don't distinguish
between the two. There should be a measurement where 0% means no
rain at all, and 100% means rain all day.

Prick.

"James Wilkinson Sword" wrote in message
news
On Thu, 20 Jul 2017 16:08:28 +0100, NY wrote:

"James Wilkinson Sword" wrote in message
news
What do you believe weather forecasters mean when they say "40% chance
of
rain"?

1) It will rain for 40% of the day.
2) There's a 40% chance it will rain at some point.

I googled it and apparently it depends on the forecaster? 1) and 2) are
completely different meanings.

Given that it includes the word "chance" (ie probability) I'd interpret
it
as the second meaning: if (hypothetically) you replayed the day many
times
(Groundhog Day!) then approx 40% of the occurrences of the day would have
some rain.

Which is of no use to me whatsoever.

Bullshit.

Pouring with rain all day is nothing like spitting for half an hour.

Sure, but ours gives both the change the range of rainfall in mm
expected and and a flag for thunderstorms too, in 3 hour blocks.
http://www.bom.gov.au/places/nsw/syd...cast/detailed/

Yet they don't distinguish between the two.

Ours does.

There should be a measurement where 0% means no rain at all, and 100%
means rain all day.

Better to show the risk in 3 or 1 hour blocks so you can see when
it is likely to rain and how heavily right thru the day and night.

On 20/07/2017 12:25, James Wilkinson Sword wrote:
On Thu, 20 Jul 2017 12:22:20 +0100, Ash Burton
wrote:

On 20/07/2017 12:13, James Wilkinson Sword wrote:
What do you believe weather forecasters mean when they say "40% chance
of rain"?

1) It will rain for 40% of the day.
2) There's a 40% chance it will rain at some point.

I googled it and apparently it depends on the forecaster? 1) and 2) are
completely different meanings.

I think it means 2

So pretty useless then. I have no idea if it will be for 20 minutes or
the entire day.

Pretty useful actually. If it is likely to rain, you know not to go out
without a coat or umbrella, drive an open topped car or start an outdoor
event that could instead take place indoors. It matters little whether
it rains for 20 minutes or all day if you are going to get soaked pat
way through.

You are correct that there are many other things where the period it
will rain for is more useful than the likelihood though.

SteveW

On Thu, 20 Jul 2017 23:00:39 +0100, Steve Walker wrote:

On 20/07/2017 12:25, James Wilkinson Sword wrote:
On Thu, 20 Jul 2017 12:22:20 +0100, Ash Burton
wrote:

On 20/07/2017 12:13, James Wilkinson Sword wrote:
What do you believe weather forecasters mean when they say "40% chance
of rain"?

1) It will rain for 40% of the day.
2) There's a 40% chance it will rain at some point.

I googled it and apparently it depends on the forecaster? 1) and 2) are
completely different meanings.

I think it means 2

So pretty useless then. I have no idea if it will be for 20 minutes or
the entire day.

Pretty useful actually. If it is likely to rain, you know not to go out
without a coat or umbrella,

Most people don't care if they get a light drizzle for 10 minutes, but do if it pours for 3 hours.

drive an open topped car

Again, I'd take the open topped car if I knew it was only going to rain for small periods. I can always close the lid.

or start an outdoor
event that could instead take place indoors.

Again, a sport like football or tennis doesn't have to stop for a bit of rain, but it would for a lot if the ground got waterlogged.

It matters little whether
it rains for 20 minutes or all day if you are going to get soaked pat
way through.

But you don't get soaked if it's only a short shower.

You are correct that there are many other things where the period it
will rain for is more useful than the likelihood though.

Every thing.

--
Freeze mother stickers, this is a **** up!

On 2017-07-20 19:38:18 +0000, James Wilkinson Sword said:

On Thu, 20 Jul 2017 16:08:28 +0100, NY wrote:

"James Wilkinson Sword" wrote in message
news
What do you believe weather forecasters mean when they say "40% chance of
rain"?

1) It will rain for 40% of the day.
2) There's a 40% chance it will rain at some point.

I googled it and apparently it depends on the forecaster? 1) and 2) are
completely different meanings.

Given that it includes the word "chance" (ie probability) I'd interpret it
as the second meaning: if (hypothetically) you replayed the day many times
(Groundhog Day!) then approx 40% of the occurrences of the day would have
some rain.

Which is of no use to me whatsoever. Pouring with rain all day is
nothing like spitting for half an hour. Yet they don't distinguish
between the two. There should be a measurement where 0% means no rain
at all, and 100% means rain all day.

Actually there shouldn't as there is no possibility of redefining the
meaning of probability to suit the needs of one person.
If you get your forecasts online, then you can get, as I mentioned
previously, an hourly forecast with the probability for each hour. That
already tells you if it is likely to rain all day or just at certain
times. If you want more than that then there are only two
possibilities. One is that you do not understand weather forecasting.
The other is that you are in fact as the troll I just killfiled
suggests. Being of a kindly and generous disposition, I will assume the
first.

Re your disgusting sig. Love is a strong feeling of affection (no more,
no less). The other topic is completely unrelated thereto. HTH.

--
Asha
minnies.opcop.org.uk
nature.opcop.org.uk
pictures.opcop.org.uk

On Thu, 20 Jul 2017 16:08:28 +0100, "NY" wrote:

"James Wilkinson Sword" wrote in message
news
What do you believe weather forecasters mean when they say "40% chance of
rain"?

1) It will rain for 40% of the day.
2) There's a 40% chance it will rain at some point.

I googled it and apparently it depends on the forecaster? 1) and 2) are
completely different meanings.

Given that it includes the word "chance" (ie probability) I'd interpret it
as the second meaning: if (hypothetically) you replayed the day many times
(Groundhog Day!) then approx 40% of the occurrences of the day would have
some rain.


There's a 50% chance that tomorrow's weather will be the same as
today's. No need for any further weather forecasts.

--
AnthonyL

On Fri, 21 Jul 2017 09:20:55 +0100, AnthonyL wrote:

On Thu, 20 Jul 2017 16:08:28 +0100, "NY" wrote:

"James Wilkinson Sword" wrote in message
news
What do you believe weather forecasters mean when they say "40% chance of
rain"?

1) It will rain for 40% of the day.
2) There's a 40% chance it will rain at some point.

I googled it and apparently it depends on the forecaster? 1) and 2) are
completely different meanings.

Given that it includes the word "chance" (ie probability) I'd interpret it
as the second meaning: if (hypothetically) you replayed the day many times
(Groundhog Day!) then approx 40% of the occurrences of the day would have
some rain.


There's a 50% chance that tomorrow's weather will be the same as
today's. No need for any further weather forecasts.

In Scotland, if it's raining today, there's a 99% chance it'll be raining tomorrow.

--
From an unknown aircraft waiting in a very long takeoff queue: "I'm ****ing bored!"
Ground Traffic Control: "Last aircraft transmitting, identify yourself immediately!"
Unknown aircraft: "I said I was ****ing bored, not ****ing stupid!"

On Fri, 21 Jul 2017 08:51:53 +0100, Asha Santon wrote:

On 2017-07-20 19:38:18 +0000, James Wilkinson Sword said:

On Thu, 20 Jul 2017 16:08:28 +0100, NY wrote:

"James Wilkinson Sword" wrote in message
news What do you believe weather forecasters mean when they say "40% chance of
rain"?

1) It will rain for 40% of the day.
2) There's a 40% chance it will rain at some point.

I googled it and apparently it depends on the forecaster? 1) and 2) are
completely different meanings.

Given that it includes the word "chance" (ie probability) I'd interpret it
as the second meaning: if (hypothetically) you replayed the day many times
(Groundhog Day!) then approx 40% of the occurrences of the day would have
some rain.

Which is of no use to me whatsoever. Pouring with rain all day is
nothing like spitting for half an hour. Yet they don't distinguish
between the two. There should be a measurement where 0% means no rain
at all, and 100% means rain all day.

Actually there shouldn't as there is no possibility of redefining the
meaning of probability to suit the needs of one person.

I'd think most people want to know if it'll rain once or all day.

If you get your forecasts online, then you can get, as I mentioned
previously, an hourly forecast with the probability for each hour. That
already tells you if it is likely to rain all day or just at certain
times.

Show me one that's anywhere near accurate.

If you want more than that then there are only two
possibilities. One is that you do not understand weather forecasting.

I understand they're rubbish at it.

The other is that you are in fact as the troll I just killfiled
suggests. Being of a kindly and generous disposition, I will assume the
first.

Re your disgusting sig. Love is a strong feeling of affection (no more,
no less). The other topic is completely unrelated thereto. HTH.

Since you snipped it I don't know which one you're referring to. But if you find it disgusting I can only assume you're a prude from the Victorian ages.

--
If you're cross-eyed and have dyslexia, can you read all right?