Many of us have noted on here how appalling the BBC precipitation forecasts have regularly been in the last few months. Even virtual nowcast observations have often been completely wrong (see Cricket thread), so it's got me wondering why? I assume they still use the NAE for their graphics? I remember Fergusson saying a while back there had been an upgrade in their hi-res model; it's been pretty much since then.

I don't want to turn this into a MetO bashing thread, because they do a brilliant job most of the time, but their precipitation forecast have been regularly diabolical of late. Why is this?

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Yes I agree they have been appaling recently its the way they do the graphics it has no relationship to the NAE model. For example on saturday 2 weeks ago the day before they put rain in the morning all over the south even though the NAE said late afternoon / evening. That is what occurred on saturday no rain in the morning but hot and sunny. Unfortunately for me I had a photography workshop on the saturday morning in Regents Park this got cancelled based on the BBC forecast the night before by the tutors.

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I think for parts of the UK today including our area both the precipitation forecast and the main forecast has been shambolic. What could be more wrong than forecasting at least 25mm of rain today and receiving 1.6mm so far with the sun shining currently at 20 pushing 21C. I say no more.

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They read from a script, and dont bother to look at the current radar and satellite before making the forecast is my guess.

And just go with what the computer shows, with out manually changing it themselfs..I rarely watch anymore as can make a better forecast by looking out the window.

 

Indeed, but why? It's got to the stage where I expect the forecast to be inaccurate at best, or just downright wrong. It's not just the odd one either. I'm sure this is a recent - last few months - trend, and mainly based around rainfall. They were superb whilst it was dry and sunny.

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I think that when it was dry and sunny with such nationally dry conditions as then it was harder to be wrong. Today is particularly notably wrong simply down to the fact it was a blanket rainfall event that was forecast and not showers which often show local variation so a bit more excuseable. Something certainly is gone awry in the UKMO PC today. 

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I certainly agree that the performance is "mixed".

To some extent you'll never pin certain events down as no one, however learned on this subject, has control on the weather.

I am more perplexed by the warning system which has been off on a few occasions, with warnings seemingly issued after the event. Thankfully its been a while since I've seen anything as bad as the Bournemouth fiasco 2 years ago

 

Pretty much this. The precipitation graphics are taken directly from their models, even in a nowcast situation where the reality on the ground is somewhat different from what their models had predcted 6/12 hours earlier. I don't know why they don't adjust the graphics to take into account what's actually going on when the reality turns out to be different from the forecast. Strange one really. 

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The problem seems to be when there is a large convective component to the preciptation where it tends to break up into lumps and that is hard to forecast using models like UKV. The big failure to my mind was not updating the forecast once this appeared in real time

My rainfall forecast yesterday has been equally shambolic because I also went with the NAE.

GFS was much more dubious about this "event" all the way along. Wish I'd gone with GFS yesterday - Lesson learned.

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There are two issues (IMO of course):

1. Since the introduction of the new graphics people eyeball their area or pinpoint their 'spot' and take the forecast literally. What else can we expect Joe Public to do when presented with such graphics? I have sat with people watching the forecast who have no interest in the weather (other than wanting to know whether it is going to rain or not) when they have declared "great, looks dry here" or "damn it's going to rain". I have then proceeded to explain that they should not take the graphic too literally but then the question is 'why not?". The simple fact of the matter is that unless they come with a clear verbal disclaimer (sometimes but rare) these graphics are not accurate enough for public consumption particularly in convective situations and of course particularly in the summer half of the year. A simple old style shower cloud graphic would server most peoples interests in a much better way.

2. Lack of probability in uk forecasts. We are way, way behind many other countries in the way that forecasts are presented. In the US and many European countries uncertainty is overcome by percentage chance of rain or other events. This is of course common on many of the forecasts available on the web. However it continues to be unavailable for the mainstream uk forecast sources, i.e. Meto and BBC. Shocking and needs a rethink.

Regards,

M

 

   

Rubbish forecast IMBY from the Beeb today. Today at present is a much better day than yesterday when I had rain/drizzle from 10:00 - 13:00 .

 

Sunny spells at the minute 22c

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well if you listen to radio solent they just keep saying its been a wet morning, when it plainly hasnt. cant understand why they dont update when the forecast has gone tits up

The Points West forecast was also a joke on the beeb after the 1 0' Clock news when the presenter, (not one of our regulars) said 'well after a very wet morning across the area things will brighten up this afternoon'..ooops.

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Last night I saw my first BBC forecast in weeks.   It showed rain persisting over here all day.   Guess what ........

I'll go back to the models I think*

 

 

 

 

 

* skinny blondes in bikinis are better than a BBC forecast any day!

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Now this is the BBC 'radar' for 2.15pm

https://twitter.com/bbcweather/status/364378631797096449/photo/1

It appears to show just a few light scattered showers approaching Old Trafford.   And bears little resemblance to the net-wx radar for the same time which shows much more widespread rain moving in ......  

(or see http://www.theweatheroutlook.com/twodata/uk-rainfall-radar.aspx and change the time to 14.15pm to compare and contrast)

Of course this may be partly due to the weird perspective on the BBC chart (which, incidently, is produced by NZ weather service Metraweather - not the BBC or the MetO)

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I wonder if some of the issue is that the NAE (for instance) is not showing what the weather will be at 15.00h but how much rain will fall in the 3 hour period. It just looks like a snapshot of where the rain will be, but isn't. This then sucks us in (especially those that look at the net weather info all the time).

That said there are a lot of people out there who had tickets for today at the cricket, decided not to come owing to the forecasts and have missed the play, and there will be no refund either as there have been enough overs... Thats what happens when you trust the BBC (Met?)

Go with the NMM model. Much more accurate than the NAE.

I don't think it's been any differentsince adam was a barrow boy

Times I've said it's going to pee down, better have the day off it's goinfg to be a washout, only to find it hasn't rained at all

Today was a good example except I chose to ignore the forcast for heavy rain and it didn't rain (until now when it was supopose

to dry up it's now thunder and lightning.

No! The Beeb are not there yet and lately they're more interested in telling us what the weather will be in St andrews for golf or

Old Traford for cricket

Still, in a way I'm glad they get it wrong sometimes... Nothings for definite with weather forcasts

 

It would be boring if it was

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You had 1.6mm Martin? wow, we have had about half a minute of light rain so far today. Last night after seeing the yellow warning for this area I told the wife to wear a waterproof coat to work today, which she did and sweated in it all morning, then I got cussed off when I got home from work for telling her it'll be pretty much rain all morning, well and truely caught out and red faced.

Computer generated graphics,pfffff. Bring back magnetic symbols I say!

Looks like its been hammering it down just to your East Jim - I'm expecting Warminster to be wet when I get home and my wife is annoyed as her classic mini has been out in all afternoon at Salisbury...

Of course, now that the rain has finally arrived here, we're getting the torrential downpours that were forecast for earlier .....

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Well it looks like we'll max out at about 4mm now that the front that brought the thunder and lightning 30ml to my West an hour or so ago has meandered across with just a splash with already signs of brighter skies to my West. Quite a disaster forecast for today here but don't expect an apology as they will be quick to highlight the vast minority who did get a dumping to justify what they predicted and this afternoon's convective front has come to their rescue somewhat for a few.

Also what happened to the prediction for heavy showers Wednesday. The last forecast I saw predicted pretty dry conditions now for Wednesday. I'l bet there be floods of rain now.

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Yeah but the GFS rainfall charts are not always right either so maybe its a case of using both Gav in future

The BBC precipitation forecasts of late have been poor but thats part of the useless graphics.

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