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.

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

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.

--
You may be a cunning linguist, but I am a master debater.

On 20/07/17 12:27, Jethro_uk wrote:
I cynically suspect that whatever methodology is being used, it allows a
retrospective "we got it right" approach.

The politically correct uncertainty principle.

The more technically correct a statment is, the less use it is.


--
A lie can travel halfway around the world while the truth is putting on
its shoes.

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.

--
AnthonyL

On Thu, 20 Jul 2017 12:46:10 +0100, 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.

The best forecast I've found (if I'm already where I'm going to be and haven't moved in the last day) is my watch. It takes a pressure reading every minute and draws a graph of the next 12 hours of weather. Basically I look out the window and look at the graph, if it's going down then I know the weather will end up worse than it already is.

--
Heaven is where the police are British, the chefs Italian, the mechanics
German, the lovers French and it is all organized by the Swiss.

Hell is where the police are German, the chefs British, the mechanics
French, the lovers Swiss and it is all organized by Italians.

On Thu, 20 Jul 2017 12:27:17 +0100, Jethro_uk 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.

I've taken it to mean that the chance of rain within the forecast area is
40%, which is subtly different.

In the last month, the Met Office has issued 3 48 hours weather warnings
for rain for my area. However, the chance of rain each time never
exceeded 5%.

I cynically suspect that whatever methodology is being used, it allows a
retrospective "we got it right" approach.

I suspect that also.

--
Change is inevitable, except from a vending machine.

"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. I have no idea

You got that right.
Prick.

On Thursday, 20 July 2017 12:13:49 UTC+1, 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.

When they explained it on the TV durign a weather documentary they said it wass the chance of rain andn showed how they calculated it.
In waether there';s a few things that can happen due to changign Highs and lows and various 'gulf' type streams the forcaster can guess which will effect which but it's a probabilty rather than a known outcome, so they use the % term.

I suppose they could use odds like bookies.

whisky-dave expressed precisely :
When they explained it on the TV durign a weather documentary they said it
wass the chance of rain andn showed how they calculated it.
In waether there';s a few things that can happen due to changign Highs and
lows and various 'gulf' type streams the forcaster can guess which will
effect which but it's a probabilty rather than a known outcome, so they use
the % term.

I suppose they could use odds like bookies.

I was wondering about that yesterday, reading the local forecast. It
was showing various percentages for each hour, 20%, 30%, 40%, 70%. Even
threats of thunderstorms. Does the first 20% mean that there is a 20%
risk of some rain within that hour, or something else?

In fact what happened was someone 2 miles away saw some brief and light
rain, hardly worth a mention. We had cloudy, no rain fell at all, no
thunder, the sun came out when it was supposed to be 70% and it was hot
and very humid.

"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.

On Thursday, 20 July 2017 15:39:29 UTC+1, Harry Bloomfield wrote:
whisky-dave expressed precisely :
When they explained it on the TV durign a weather documentary they said it
wass the chance of rain andn showed how they calculated it.
In waether there';s a few things that can happen due to changign Highs and
lows and various 'gulf' type streams the forcaster can guess which will
effect which but it's a probabilty rather than a known outcome, so they use
the % term.

I suppose they could use odds like bookies.

I was wondering about that yesterday, reading the local forecast. It
was showing various percentages for each hour, 20%, 30%, 40%, 70%. Even
threats of thunderstorms. Does the first 20% mean that there is a 20%
risk of some rain within that hour, or something else?

I guess that what it means, perhaps some may think that it means there's a 20% chance of rain in their lifetime, how anyone would come to that conclusion escapes me, but there's some on here that think the new doctor who is a women ;-)



In fact what happened was someone 2 miles away saw some brief and light
rain, hardly worth a mention. We had cloudy, no rain fell at all, no
thunder, the sun came out when it was supposed to be 70% and it was hot
and very humid.

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?
--
Jim S

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.

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.

"Harry Bloomfield" wrote in message
news
whisky-dave expressed precisely :
When they explained it on the TV durign a weather documentary they said
it wass the chance of rain andn showed how they calculated it.
In waether there';s a few things that can happen due to changign Highs
and lows and various 'gulf' type streams the forcaster can guess which
will effect which but it's a probabilty rather than a known outcome, so
they use the % term.

I suppose they could use odds like bookies.

I was wondering about that yesterday, reading the local forecast. It was
showing various percentages for each hour, 20%, 30%, 40%, 70%. Even
threats of thunderstorms. Does the first 20% mean that there is a 20% risk
of some rain within that hour,

Yep.

or something else?

Nope.

In fact what happened was someone 2 miles away saw some brief and light
rain, hardly worth a mention.

Sure, but that's why it said 20% etc and not 100%

We had cloudy, no rain fell at all, no thunder, the sun came out when it
was supposed to be 70%

That's why it said 70% and not 100%

and it was hot and very humid.

On Thu, 20 Jul 2017 20:38:18 +0100, "James Wilkinson Sword"
wrote:

snip

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

We know but aren't you only taking notice of a part of the information
on offer?

Yet they don't distinguish between the two.

They do, but not by using the single variable you mention in
isolation.

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

0% is just that, no rain at all that period

'There is a 100% chance of rain' (as the definition of that
prediction) means that it *will* happen (as a prediction) at some time
during that 24 hour period (say) and the *additional information*
will generally determine how hard and for how long it will (is likely)
rain during that same interval.

So, whilst 'There is a 100% chance of rain today' wouldn't be of use
to you in isolation, it would be of use to anyone thinking of watering
their garden or painting their shed 'that day'.

It could rain heavily ... it could rain all morning ... there may just
be light shower in some places ... are examples of the additional
information you weren't considering?

Cheers, T i m

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.

On Thu, 20 Jul 2017 21:19:30 +0100, T i m wrote:

On Thu, 20 Jul 2017 20:38:18 +0100, "James Wilkinson Sword"
wrote:

snip

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

We know but aren't you only taking notice of a part of the information
on offer?

No, all it says is "Rain: 60%"

Yet they don't distinguish between the two.

They do, but not by using the single variable you mention in
isolation.

They do on the sites I've been to.

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

0% is just that, no rain at all that period

'There is a 100% chance of rain' (as the definition of that
prediction) means that it *will* happen (as a prediction) at some time
during that 24 hour period (say) and the *additional information*
will generally determine how hard and for how long it will (is likely)
rain during that same interval.

I've never seen this additional information of which you speak. Show me a website with this.

So, whilst 'There is a 100% chance of rain today' wouldn't be of use
to you in isolation, it would be of use to anyone thinking of watering
their garden or painting their shed 'that day'.

It could rain heavily ... it could rain all morning ... there may just
be light shower in some places ... are examples of the additional
information you weren't considering?

For most activities a light shower is not the same as pouring all day.

--
A penny saved is ridiculous.

T i m wrote:
On Thu, 20 Jul 2017 20:38:18 +0100, "James Wilkinson Sword"
wrote:

snip

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

We know but aren't you only taking notice of a part of the information
on offer?

Yet they don't distinguish between the two.

They do, but not by using the single variable you mention in
isolation.

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

0% is just that, no rain at all that period

'There is a 100% chance of rain' (as the definition of that
prediction) means that it *will* happen (as a prediction) at some time
during that 24 hour period (say) and the *additional information*
will generally determine how hard and for how long it will (is likely)
rain during that same interval.

So, whilst 'There is a 100% chance of rain today' wouldn't be of use
to you in isolation, it would be of use to anyone thinking of watering
their garden or painting their shed 'that day'.

It could rain heavily ... it could rain all morning ... there may just
be light shower in some places ... are examples of the additional
information you weren't considering?

Cheers, T i m

Please don't feed the PHucker pillock.

"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.

Bull****.

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.

I have an Amazon Echo and its very fond of this. Yesterday it told me that
there is a 25 percent of rain today, well it did rain today but mostly
because the cloudbase was so low we got enveloped in it and it was kind of
like drizzly mist not rain as such.
So does this mean I was in the 25 percent of my region that got it or that
I got 25 percent of the possible rain?
No idea, sorry.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"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.

In article , Harry Bloomfield
writes
whisky-dave expressed precisely :
When they explained it on the TV durign a weather documentary they
said it wass the chance of rain andn showed how they calculated it.
In waether there';s a few things that can happen due to changign
Highs and lows and various 'gulf' type streams the forcaster can
guess which will effect which but it's a probabilty rather than a
known outcome, so they use the % term.

I suppose they could use odds like bookies.

I was wondering about that yesterday, reading the local forecast. It
was showing various percentages for each hour, 20%, 30%, 40%, 70%. Even
threats of thunderstorms. Does the first 20% mean that there is a 20%
risk of some rain within that hour, or something else?

Either way it's useless information. I want to know if it is going to
rain or not. Of course you can never prove them wrong.
In fact what happened was someone 2 miles away saw some brief and light
rain, hardly worth a mention. We had cloudy, no rain fell at all, no
thunder, the sun came out when it was supposed to be 70% and it was hot
and very humid.
So they weren't wrong :-)
--
bert

In article ,
whisky-dave writes
On Thursday, 20 July 2017 15:39:29 UTC+1, Harry Bloomfield wrote:
whisky-dave expressed precisely :
When they explained it on the TV durign a weather documentary they said it
wass the chance of rain andn showed how they calculated it.
In waether there';s a few things that can happen due to changign Highs and
lows and various 'gulf' type streams the forcaster can guess which will
effect which but it's a probabilty rather than a known outcome, so
they use
the % term.

I suppose they could use odds like bookies.

I was wondering about that yesterday, reading the local forecast. It
was showing various percentages for each hour, 20%, 30%, 40%, 70%. Even
threats of thunderstorms. Does the first 20% mean that there is a 20%
risk of some rain within that hour, or something else?

I guess that what it means, perhaps some may think that it means
there's a 20% chance of rain in their lifetime, how anyone would come
to that conclusion escapes me, but there's some on here that think the
new doctor who is a women ;-)


She's reproduced already?

In fact what happened was someone 2 miles away saw some brief and light
rain, hardly worth a mention. We had cloudy, no rain fell at all, no
thunder, the sun came out when it was supposed to be 70% and it was hot
and very humid.


--
bert

Only time I've been enveloped in rain is up mountains, like Ben Nevis 4 days ago.


On Thu, 20 Jul 2017 22:04:18 +0100, Brian Gaff wrote:

I have an Amazon Echo and its very fond of this. Yesterday it told me that
there is a 25 percent of rain today, well it did rain today but mostly
because the cloudbase was so low we got enveloped in it and it was kind of
like drizzly mist not rain as such.
So does this mean I was in the 25 percent of my region that got it or that
I got 25 percent of the possible rain?
No idea, sorry.
Brian



--
Every day more money is printed for Monopoly than the US Treasury.

On Thu, 20 Jul 2017 22:18:13 +0100, bert wrote:

In article ,
whisky-dave writes
On Thursday, 20 July 2017 15:39:29 UTC+1, Harry Bloomfield wrote:
whisky-dave expressed precisely :
When they explained it on the TV durign a weather documentary they said it
wass the chance of rain andn showed how they calculated it.
In waether there';s a few things that can happen due to changign Highs and
lows and various 'gulf' type streams the forcaster can guess which will
effect which but it's a probabilty rather than a known outcome, so
they use
the % term.

I suppose they could use odds like bookies.

I was wondering about that yesterday, reading the local forecast. It
was showing various percentages for each hour, 20%, 30%, 40%, 70%. Even
threats of thunderstorms. Does the first 20% mean that there is a 20%
risk of some rain within that hour, or something else?

I guess that what it means, perhaps some may think that it means
there's a 20% chance of rain in their lifetime, how anyone would come
to that conclusion escapes me, but there's some on here that think the
new doctor who is a women ;-)

She's reproduced already?

Time travel innit? She's present in two or more times at once, so she's a women.

--
"Flashlights are tubular metal containers kept in a flight bag for the purpose of storing dead batteries."

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 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 08:20:55 GMT, lid (AnthonyL)
wrote:

snip

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

;-)

A mate moved from the UK to Canada then spent some time in California.
He said one of the more striking differences between living there
(California) and the UK is that in California they planned to go
boating 'next Thursday', the chances are that the weather will be
pretty much the same as it was the day they planned the trip. ;-)

Over here, I'd say it's rarely possible to accurately predict the
weather that afternoon and you can experience the weather from at
least three seasons in the same day. ;-)

'Right kids, get your flip flops, shoes, Wellingtons, shorts, coats
and don't forget the sun cream ...' ;-)

Cheers, T i m

On Fri, 21 Jul 2017 09:58:46 +0100, T i m wrote:

On Fri, 21 Jul 2017 08:20:55 GMT, lid (AnthonyL)
wrote:

snip

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

;-)

A mate moved from the UK to Canada then spent some time in California.
He said one of the more striking differences between living there
(California) and the UK is that in California they planned to go
boating 'next Thursday', the chances are that the weather will be
pretty much the same as it was the day they planned the trip. ;-)

Over here, I'd say it's rarely possible to accurately predict the
weather that afternoon and you can experience the weather from at
least three seasons in the same day. ;-)

'Right kids, get your flip flops, shoes, Wellingtons, shorts, coats
and don't forget the sun cream ...' ;-)

I don't care what the weather is. A pair of shorts works for anything. Humans are waterproof and warmblooded and don't require a change of clothes for a change in the weather.

--
A lawyer is simply a computer on two legs. It cannot think for itself, all it can do is remember vast amounts of information - past cases, billions of strange laws, etc.

On Fri, 21 Jul 2017 11:31:11 +0100, Jethro_uk wrote:

On Fri, 21 Jul 2017 09:58:46 +0100, T i m wrote:

A mate moved from the UK to Canada then spent some time in California.
He said one of the more striking differences between living there
(California) and the UK is that in California they planned to go boating
'next Thursday', the chances are that the weather will be pretty much
the same as it was the day they planned the trip. ;-)

As my brother (whos moved to the US) frequently says:

In the US they have climate. In the UK we have weather.

At least we don't have building-wrecking tornadoes.

--
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 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 20/07/2017 20:57, Rod Speed wrote:
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.
This thread reminds me of my favourite weather forecast. "It may rain at
times in places" 100% accurate, but also 100% useless, in my opinion.

On Sat, 22 Jul 2017 10:37:02 Broadback wrote:

On 20/07/2017 20:57, Rod Speed wrote:
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.
This thread reminds me of my favourite weather forecast. "It may rain
at times in places" 100% accurate, but also 100% useless, in my opinion.

No, it's not 100% useless. It tells you that it might be a good idea to
take an umbrella with you, particularly if you're going for a walk.

David

--
David Rance writing from Caversham, Reading, UK

On Mon, 24 Jul 2017 10:13:38 +0100, Jethro_uk wrote:

On Fri, 21 Jul 2017 12:06:28 +0100, James Wilkinson Sword wrote:

On Fri, 21 Jul 2017 11:31:11 +0100, Jethro_uk
wrote:

On Fri, 21 Jul 2017 09:58:46 +0100, T i m wrote:

A mate moved from the UK to Canada then spent some time in California.
He said one of the more striking differences between living there
(California) and the UK is that in California they planned to go
boating 'next Thursday', the chances are that the weather will be
pretty much the same as it was the day they planned the trip. ;-)

As my brother (whos moved to the US) frequently says:

In the US they have climate. In the UK we have weather.

At least we don't have building-wrecking tornadoes.

Have you been to Birmingham ?

I was talking about the weather, not Muslims.

--
What is the difference between a battery and a woman?
A battery has a positive side.