[Storm Dennis Atlantic Storm 4]

2 hours ago, knocker said:

I have no idea what is behind Exeter's thinking, way above my pay grade, but from where I'm sitting it looks very much down to the different evolution and structure of Dennis as against Ciara

The latter formed and tracked quickly across the Atlantic in about 36 hours, deepening rapidly as it went which made forecasting of the impacts extremely tricky far in advance.

Dennis on the other hand, although also deepening quickly, is slower to move and also curves more north east and merges with the upper trough in situ, courtesy of strong ridging from the subtropical high and the re curving jet which helps to pin down the outcome a tad easier.and earlier(from where I'm sitting of course). Still liable to adjustment

You're right, that's exactly what the MO is saying as to why the warning is out so 'early'.

What makes me smile are the conspiracy theories as to why or not the MO issue a warning and then what sort of warning it is. They don't always get it right and their reasoning isn't always completely transparent but I also don't believe that they've got a secret agenda to spite the public!

[Storm Ciara - Atlantic storm 3]

1 hour ago, Man With Beard said:

OK so looking at the AROME 06Z this morning, it was showing more local differences - in general, most places got to 90kmh (so between mid 50s and low 60s mph) and favoured spots + E Anglia got the 110kmh band (so 70s mph+) 

So perhaps a little more useful than longer range models for seeing the picture in one's own back yard. 

Very interesting. Thanks!

[Storm Ciara - Atlantic storm 3]

1 hour ago, Mapantz said:

I know they use it, but i'm not sure about the website/app forecasts.

Current ECM shows around 50 km/h gusts here, which is right inline with what I am recording  now - circa 30mph. The BBC are showing 60mph.

I naively thought that most 'simply' lifted it from whichever model they use so, to take the case of GFS-based forecasts which @Man With Beard was helping me with earlier, it's less than suitable for local forecasting. It would certainly *appear* (I may very well be wrong) that sites like XCWeather and, dare I say it, this one do exactly that for their 'local' forecasts because, for the 5 or 6 locations I was following today (including Birmingham, Bristol, Colchester and Hull - so a fair spread), they seemed to bear very little resemblance to reality.

[Storm Ciara - Atlantic storm 3]

Just now, Man With Beard said:

No you're not interpreting anything wrong - in the case of Birmingham clearly even the GFS didn't work. My sense is that 60mph was a fair reflection for most locations but, perhaps if the GFS does have a weakness, it is that it doesn't really do the fine details - it just paints everywhere within 20 miles the same. You've got me thinking too check how high definition models like AROME did - did they pick the local variations? I shall check and post what I find

Thank you. I appreciate your patience!

[Storm Ciara - Atlantic storm 3]

1 minute ago, Man With Beard said:

No I don't think so actually - the GFS was generally around the 60mph mark for most inland areas and a few favoured spots + coasts were predicted at 70mph+ for a while. Pretty accurate. It never played with the 80mph+ category like some others did. At least that's my recollection? 

I believe you but, let's take Birmingham for example, the GFS-based forecasts were saying gusts in the mid to high 60s for 4 hours in a row but it never gusted above the low 50s. The GFS charts I saw seemed to agree with this. I'm not arguing - I can see that you know A LOT more than I do - so I would like to understand where I'm going wrong with how I'm interpreting things.

[Storm Ciara - Atlantic storm 3]

1 minute ago, Mapantz said:

One model I don't trust is the Arpege. It wouldn't surprise me if BBC Weather were using that as it had ludicrous gust figures for here, and still does now!

BBC == Meteo == ECM?

[Storm Ciara - Atlantic storm 3]

4 minutes ago, Man With Beard said:

Fair point. One reflection I will take away is that the ECM overdid the event (it had Chichester with 86mph winds at just T12) , and I usually trust the ECM to be the closest - but the GFS was far closer to the mark overall. In fact, the GFS has been pretty good with most wind events in the past 6 years (it nailed Feb 2014 too) once it gets within T72. I know where I will be looking first next time! 

I am definitely showing my ignorance here but the GFS charts/forecasts I saw were also way over the top in terms of wind speeds. Am I looking at the wrong things? I genuinely want to learn!

[Storm Ciara - Atlantic storm 3]

29 minutes ago, A Face like Thunder said:

I don't think it's fair to call this event over-hyped.....

I agree. I'm glad the people I care about heeded the advice and stayed indoors today. I also feel sad for all the people who are suffering and will continue to suffer for many days to come as a result of what has happened to them.

The 'weather nerds' (I'm here, so I'm guilty as charged) certainly did over-hype it though. The models weren't great in the end - 60-70 mph gusts as squalls go over is not the same as hours of 60-70 mph widespread inland gusts - but quite a few people were rubbing their hands with glee at the prospect of half the country being flattened whilst giving the Met Office a kicking for resisting the urge to over-egg it too soon because it didn't fit with what they wanted to happen. Let's be honest, it didn't really happen as advertised.

I apologise. I know I'm being a bit provocative but it you read through this thread from the start, you might see what I'm getting at.

[Storm Ciara - Atlantic storm 3]

52 minutes ago, matty40s said:

There have been widespread 70mph gusts, Kent, Lincolnshire, Cambridgshire, Notts, Derbys, etc

Fair enough, but looking back over the predictions (which is all they were), 'we' were potentially in for hours of it, not sporadic gusts associated with frontal activity. (I feel very sorry for the poor people who have suffered as a result.)

The MO were getting quite a lot of stick about their forecasts and warnings but I don't think they were that far off in the end, even when it comes to the earlier amber warning in the south east which is now starting to look at the very least prescient.

[Storm Ciara - Atlantic storm 3]

It's still probably too early but dare I venture to suggest that the MO got more of this right than wrong and that the main models at least (I'm looking at you GFS and ECM) were quite a way off both in terms of timing and wind predictions? Ok, the squall lines have been nasty for some but, overall, the wind event was overdone in terms of the numbers. Yes, people needed to be warned because it is fairly unusual but the widespread 70+ mph inland gusts people on here were going on about only yesterday just haven't happened (yet!). Still, it's all useful information that will hopefully improve the models further.