The Weather Thread 2023

[jfaragher]

1 hour ago, Sheffield Steve said:

Outlier or not, it’s a possibility.  The GFS 0z is horrendous, bringing heavy thundery rain over the site from the Wednesday right through to Saturday morning.  It would be carnage.  Too early to panic, plenty of time for things to change….

 

1-5mm 3hr precip accumulations are not "heavy thundery showers" - a heavy shower would bring 4-8mm per hour.  At <2mm an hour, you're talking light showers, or very light persistent rain.

/edit - I guess it *could* fall as a heavy shower every three hours for a day, but that wouldn't be terrible, it would just be annoying.

Edited June 8, 2023 by jfaragher

[BambooShanks]

4 minutes ago, Crazyfool01 said:

Has it changed yet ? 

Currently showing rain of varying intensity from wednesday onwards. Next run will be out in a few hours, which will no doubt be different.

We've still got over a week to go before the forecasts start becoming in any way reliable so no need to worry... yet.

[parsonjack]

Not sure I want to be saved by this.....

 

[DareToDibble]

Realistically, when can we start to be confident that the forecasts are right? This time next week?

[Avalon_Fields]

Could someone please ban me from accessing this thread every 15 minutes. 

[sprocketrocket]

19 minutes ago, jfaragher said:

1-5mm 3hr precip accumulations are not "heavy thundery showers" - a heavy shower would bring 4-8mm per hour.  At <2mm an hour, you're talking light showers, or very light persistent rain.

/edit - I guess it *could* fall as a heavy shower every three hours for a day, but that wouldn't be terrible, it would just be annoying.

with out wanting to be all Nal about it... 1-5 and 4-8 cross over in a Venn. 

We're all doomed. 

NFCNFRNFC

Edit...

Hang on. 1 hr and 3 hrs are different though aren't they. I'll shut up, but am leaving the above there for prosperity. 

Edited June 8, 2023 by sprocketrocket
I'm an idiot

[BambooShanks]

Just now, DareToDibble said:

Realistically, when can we start to be confident that the forecasts are right? This time next week?

Tuesday the 20th for any degree of accuracy for the following 36 hours.

Though from next week the trend for the week ahead will start to become clear.

So as grim as some forecasts may look, nothing is set in stone yet so anything can happen.

[nikkic]

29 minutes ago, DareToDibble said:

Realistically, when can we start to be confident that the forecasts are right? This time next week?

Day before the festival 

[watsonjm]

36 minutes ago, DareToDibble said:

Realistically, when can we start to be confident that the forecasts are right? This time next week?

Stick your head out the tent each morning and go from there

[Jacko45]

Met Office has always been the most accurate for me.

I'll check that a week out and I reckon it'll be as close as. 

[Havors]

13 minutes ago, Jacko45 said:

Met Office has always been the most accurate for me.

I'll check that a week out and I reckon it'll be as close as. 

It is the most accurate shortish range by far. My mate using for fell running and when he did the Bob Graham run... where the weather is very important. Says its the best to use.

[Duggyfresh44]

10 hours ago, Alvoram said:

Having said that... And despite these 'poor' runs and all the panic in here... This isn't screaming 'mud bath' to me...

Not a lot of rain between now and the Friday of the festival at all really. 

To put all this into context, this is a prediction from a couple of weeks before 2019. Cold wet and miserable. Which then turned out to be boiling with wall to wall sunshine and not a single drop of rain.

 

 

[briddj]

1 hour ago, DareToDibble said:

Realistically, when can we start to be confident that the forecasts are right? This time next week?

3 days before really. But we could see trends before then.

[fred quimby]

This is just the same as every year. 2019 and 2022 were the same. Rain rain rain, oh wait all OK. We have also had it the other way around when it was all sun and that turned to rain

[NotAnInsider]

The ECMWF box and whisker things are starting to cover the first few days of the festival. These are the result of multiple runs of the model, each with slightly different variables, that try to produce a more of a probabilistic forecast (these things could happen) rather than a deterministic forecast (this thing will happen). At this sort of range the models are chopping and changing, so this is quite useful right now.

On the plot the thickest box is the 50% likely outcome, with the thin lines representing the 10% extremes. When the different model runs are in agreement, normally close in time, you won't see any whiskers, just box. 

So it's basically warmer than average and a slight chance of rain, for now. But the range is too great to say for sure.

[Nerraw2525]

1 hour ago, DareToDibble said:

Realistically, when can we start to be confident that the forecasts are right? This time next week?

Weather forecast during Countryfile on BBC on the Sunday before the festival tends to be accurate. 

There isn't even agreement for what the weather will be like for this weekend.

[gooner1990]

2 minutes ago, fred quimby said:

This is just the same as every year. 2019 and 2022 were the same. Rain rain rain, oh wait all OK. We have also had it the other way around when it was all sun and that turned to rain

Same in 2010.

[Jacko45]

6 minutes ago, Nerraw2525 said:

Weather forecast during Countryfile on BBC on the Sunday before the festival tends to be accurate. 

There isn't even agreement for what the weather will be like for this weekend.

 

Yep that's usually very accurate. 

[Sasperella2]

When is the next of these so called "ensembles" ?? 

 

[fightoffyour]

1 hour ago, DareToDibble said:

Realistically, when can we start to be confident that the forecasts are right? This time next week?

I was checking Thursday morning before leaving and I'm pretty sure that Sat/Sun we're still on a knife-edge although the prevalent patterns were ultimately realised.

[Justcalledtosay]

@Sheffield Steve I’m in Sheffield for work today. Chill out with the Armageddon predictions or I’m coming to find you 😉

[faymondo]

I just want it dry setting up on Wednesday. Rather no rain at all but at least I can prepare for any eventualities from my dry base camp. This will mostly involve a poncho and various levels of booze. 

[Justcalledtosay]

27 minutes ago, NotAnInsider said:

The ECMWF box and whisker things are starting to cover the first few days of the festival. These are the result of multiple runs of the model, each with slightly different variables, that try to produce a more of a probabilistic forecast (these things could happen) rather than a deterministic forecast (this thing will happen). At this sort of range the models are chopping and changing, so this is quite useful right now.

On the plot the thickest box is the 50% likely outcome, with the thin lines representing the 10% extremes. When the different model runs are in agreement, normally close in time, you won't see any whiskers, just box. 

So it's basically warmer than average and a slight chance of rain, for now. But the range is too great to say for sure.

This appears sensible. More of this please

[gooner1990]

1 minute ago, faymondo said:

I just want it dry setting up on Wednesday. Rather no rain at all but at least I can prepare for any eventualities from my dry base camp. This will mostly involve a poncho and various levels of booze. 

2011 started off on a low point when I was putting my tent up in the rain

[stuartbert two hats]

1 hour ago, DareToDibble said:

Realistically, when can we start to be confident that the forecasts are right? This time next week?

19th June