Graphics gone awol again,
Forecast for West midlands is heavy rain clearing, dry by noon with a
few brighter spells this afternoon. Dry but rather cloudy tonight.
Gaphics show heavy rain symbols for Weston Coyney throughout the day
well into the night. They cant both be right!!
Last few hours very wet here with 27.8 mm so far.

Graham (Weston Coyney)

In message , Graham
writes
Graphics gone awol again,
Forecast for West midlands is heavy rain clearing, dry by noon with a
few brighter spells this afternoon. Dry but rather cloudy tonight.

I think that's the forecast of the human forecasters, which is updated
two or three times a day..

Gaphics show heavy rain symbols for Weston Coyney throughout the day
well into the night.

Whereas that's the latest computer forecast and is continually updated.

They cant both be right!!

My experience has been that for the next 6-12 hours the computer
forecast is better, perhaps because it's more up to date.

Last few hours very wet here with 27.8 mm so far.

Not much different here in Surrey.
--
John Hall

You can divide people into two categories:
those who divide people into two categories and those who don't

Graham wrote:

Graphics gone awol again,
Forecast for West midlands is heavy rain clearing, dry by noon with a
few brighter spells this afternoon. Dry but rather cloudy tonight.
Gaphics show heavy rain symbols for Weston Coyney throughout the day
well into the night. They cant both be right!!
Last few hours very wet here with 27.8 mm so far.

Graham (Weston Coyney)

The computer-generated hour-by-hour forecasts and the human-produced
text are all too often telling very different stories. As I said in
another thread recently, the computer models today are pretty good at
predicting the future state of the atmosphere but pretty rubbish at
predicting the actual weather that will occur. Raw model output was
never intended to be an end-user product.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
https://peakdistrictweather.org
twitter: @TideswellWeathr

On Tuesday, 25 August 2020 11:05:31 UTC+1, Norman Lynagh wrote:
Graham wrote:

Graphics gone awol again,
Forecast for West midlands is heavy rain clearing, dry by noon with a
few brighter spells this afternoon. Dry but rather cloudy tonight.
Gaphics show heavy rain symbols for Weston Coyney throughout the day
well into the night. They cant both be right!!
Last few hours very wet here with 27.8 mm so far.

Graham (Weston Coyney)

The computer-generated hour-by-hour forecasts and the human-produced
text are all too often telling very different stories. As I said in
another thread recently, the computer models today are pretty good at
predicting the future state of the atmosphere but pretty rubbish at
predicting the actual weather that will occur. Raw model output was
never intended to be an end-user product.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
https://peakdistrictweather.org
twitter: @TideswellWeathr

The hourly forecast is different to the text forecast. The hourly forecast is showing heavy rain for most of the day but the text forecast states it will clear northeastwards. It is dry now so it looks like the text forecast is correct.

Nicholas
Meir Heath, Stoke-On-Trent 250 metres above sea level.

It just goes to show - if you want to know what the weather will be like, look at the radar (and satellite imagery). It may also provide an explanation for the odd continuation of the rain symbols in the site-specific forecast - presumably the wrap-around feature as the 'hook' of the occluded front comes sweeping in from the west. However, the rain associated with this does not look that close to you right now (just getting to Anglesey at 1230BST). Why have an hourly forecast if you do not distinguish between the hours?

The MeteoGroup version of events for Stoke (and that is not just raw model data) via BBC Weather centre shows sunshine and showers till c17h then rain takes over - I guess that would be the wrap-around arriving. https://www..bbc.co.uk/weather/2636841

Julian
West Molesey, Surrey

Julian Mayes wrote:

It just goes to show - if you want to know what the weather will be
like, look at the radar (and satellite imagery). It may also provide
an explanation for the odd continuation of the rain symbols in the
site-specific forecast - presumably the wrap-around feature as the
'hook' of the occluded front comes sweeping in from the west.
However, the rain associated with this does not look that close to
you right now (just getting to Anglesey at 1230BST). Why have an
hourly forecast if you do not distinguish between the hours?

The MeteoGroup version of events for Stoke (and that is not just raw
model data) via BBC Weather centre shows sunshine and showers till
c17h then rain takes over - I guess that would be the wrap-around
arriving. https://www.bbc.co.uk/weather/2636841

Julian
West Molesey, Surrey


Indeed. The radar is the best short-range forecasting tool.


--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
https://peakdistrictweather.org
twitter: @TideswellWeathr

On Tuesday, August 25, 2020 at 11:05:31 AM UTC+1, Norman Lynagh wrote:
Graham wrote:

Graphics gone awol again,
Forecast for West midlands is heavy rain clearing, dry by noon with a
few brighter spells this afternoon. Dry but rather cloudy tonight.
Gaphics show heavy rain symbols for Weston Coyney throughout the day
well into the night. They cant both be right!!
Last few hours very wet here with 27.8 mm so far.

Graham (Weston Coyney)

The computer-generated hour-by-hour forecasts and the human-produced
text are all too often telling very different stories. As I said in
another thread recently, the computer models today are pretty good at
predicting the future state of the atmosphere but pretty rubbish at
predicting the actual weather that will occur. Raw model output was
never intended to be an end-user product.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
https://peakdistrictweather.org
twitter: @TideswellWeathr
----------------------------------------------------------------------
I agree with you Norman but

'Raw model output was
never intended to be an end-user product.'

You must be joking.
That is the very intention.
Misguided though it may be.

Len
Wembury

---------------------------------------------
I agree with you Norman but

'Raw model output was
never intended to be an end-user product.'

You must be joking.
That is the very intention.
Misguided though it may be.

Len
Wembury

I am tempted to ask, whose intention, Len? If you have to produce hourly forecast for hundreds of thousands of places worldwide, you have to drive this with model output. But you should modify and refine it with observations using thousands of regression equations. Which models work best in particular places at different times of year and in different airflow types. I have no knowledge on how the MO do all this though.

Re the MeteoGroup / BBC forecast for Stoke this afternoon, it looked to me via the radar that the early afternoon showers did cluster together a bit for a time. However, the forecast of the main band of wrap-around rain arriving at 5pm looks spot on to me. Maybe Graham will post later.

If this was the weather and climate forum I'd be able to add a radar image to prove it....

Julian

Nicholas Randall wrote:


The hourly forecast is different to the text forecast. The hourly
forecast is showing heavy rain for most of the day but the text
forecast states it will clear northeastwards. It is dry now so it
looks like the text forecast is correct.

Nicholas
Meir Heath, Stoke-On-Trent 250 metres above sea level.

Yes the text forecast was spot on despite the graphics still showing
heavy rain well into tonght. No rain since 11.10 today, just mostly
cloudy.
I also have a problem with rain today rainfall app, it's being showing
rainfall all around us for a while now but its still dry??


Graham (Weston Coyney)

On Tuesday, August 25, 2020 at 5:56:09 PM UTC+1, Julian Mayes wrote:
---------------------------------------------
I agree with you Norman but

'Raw model output was
never intended to be an end-user product.'

You must be joking.
That is the very intention.
Misguided though it may be.

Len
Wembury

I am tempted to ask, whose intention, Len? If you have to produce hourly forecast for hundreds of thousands of places worldwide, you have to drive this with model output. But you should modify and refine it with observations using thousands of regression equations. Which models work best in particular places at different times of year and in different airflow types. I have no knowledge on how the MO do all this though.

Re the MeteoGroup / BBC forecast for Stoke this afternoon, it looked to me via the radar that the early afternoon showers did cluster together a bit for a time. However, the forecast of the main band of wrap-around rain arriving at 5pm looks spot on to me. Maybe Graham will post later.

If this was the weather and climate forum I'd be able to add a radar image to prove it....

Julian
-------------------------------------------------------------------------
Julian,
The UKMO's intention.
Get it all done remotely by computers and cut staff.
That has been the obvious intention since they closed all the local offices..
Anyway, having been given bags of money for supercomputers they had better use them for improved forecasts.

I am no expert on the goings on at UKMO HQ regarding forecasting but it is clear as you say, that to produce site specific forecasts then model output is the way forward. The trouble is, model output atm is not up to giving the necessary detail.
It is hard for those in the central forecasting office to keep up when they see that the hourly model forecasts are sometimes going wrong. I am not sure how often the model is run, is it every 3 hours these days? At some stage they must have to fudge to a nowcast when they look at the radar sequence.. That is what seems to happen when I look at the forecast hourly. However, Jo Public is not an anorak like us on this newsgroup. They will look at the hourly forecast once at 0900hrs for the day and woe betide if it is wrong..
Suggesting to Jo Public that they must look at the forecast every hour through the day leads to howls of laughter and derision. Moving the goal posts all the time to ensure you score a goal has been mentioned.

Len