josh-weather

GFS 06z and 00z both are warm outliers in the ensembles. The ensembles have quite a cluster of runs colder than average further north. Less so shown below for London but still the OP is way up at the top.

blizzard81 yes you're right probably was a bit harsh. Thanks!

blizzard81 Said with confidence, but why?

@TEITS An outlier compared to the ensemble members though - I thought the point of the control was to see if resolution was having an effect. If the op and control are the same then resolution isn't affecting the ensemble outcomes, which I'd take as reinforcing the outcome of the ensembles overall - which are mostly mild for that date. In other words the fact op and control match is an indication that the ensemble as a whole might be decently reliable. Please somebody explain where I'm getting this wrong, everything I learnt I learnt from this place

Snow aside, I can't really see much difference between today and yesterday. Still going to be cold, not dramatically so but nothing much different to what has been showing for a while. Snow wise isn't it partly a matter of seeing what turns up anyway? edit: Fair enough, the low did move south again - quite a shame for southern regions if that's what happens.

But model performance hasn't dropped... Has it?

Here you go (Available here if you were wondering!)

If I'm reading it right, higher is more accurate. And it is showing the day 10 accuracy, so for example on the 17th, how accurate were the forecasts for the 27th compared to what a really happened on the 27th. There's a big dip at Christmas which is because there is less data available on Christmas day, meaning the forecasts made on that day have lower accuracy. It is showing specifically accuracy of 500hpa anomaly.

Latest from EC46. So it moved like the EPS did. Though I'm definitely not qualified to say what the implications are! https://charts.ecmwf.int/permalinks/mean-zonal-wind-at-10-hpa-extended-range-forecast-64400

The ECM runs out to 10 days, I thought we wouldn't see effects from the potential SSW until the very end of the run or afterwards, and certainly not at all a week or two ago?

Has anything really changed that much since yesterday? You folks are the best but I swear this thread could be a case study in crowd dynamics I'm waiting for the 46 https://charts.ecmwf.int/permalinks/mean-zonal-wind-at-10-hpa-extended-range-forecast-39219

In this case I think it was just the 12Z not the 18

To be fair it doesn't have to go all the way across the continent to end the cold spell in the UK!

RTE reporting more than 100,000 homes and businesses in Ireland without power due to the storm! More than 100,000 properties without power due to storm WWW.RTE.IE More than 100,000 homes and businesses are without power this morning due to Storm Debi, an ESB spokesperson has said, as a Status Red wind warning remains in effect for...

Now that I'm not sure of! It does say "GFS / NCEP / US National Weather Service" when you're in the wind overlay to be fair, not just GFS. But I had always assumed the actual wind map (rather than the over animations it can overlay) was GFS. The source code is available so maybe it would be possible to see exactly what it does.