The 12z ENS for Aberdeen look cold throughout the entire run as well as continued precipitation spikes - a recipe for snow maybe?

 

No, rain. It’s cool rather than cold.

Looking at some long range data - EC goes for above average heights to our north from Scandinavia to Iceland to Greenland = a perfect recipe for an easterly if this came about even better than it is forecast to be colder than average for Scandinavia:

 

 

Yes, but I feel these scenarios are a perpetual jam tomorrow at the moment, can't get them out of T168+.

Yes, been like a broken record for the South East this winter. Or in fact most of the last 10 !

Looking at some long range data - EC goes for above average heights to our north from Scandinavia to Iceland to Greenland = a perfect recipe for an easterly if this came about even better than it is forecast to be colder than average for Scandinavia:

 

Have you got the height anomalies? Those charts are ppn and temp.

ECM looks pretty disappointing in the longer term compared to some of the other output this evening.

Agreed Rob but it could just be playing slow catch-up.

 

Agreed Rob but it could just be playing slow catch-up.

 

Which is the most reliable model would you say? - The ECM is only updated every 12 hours so surely it's less reliable than GFS?

 

Which is the most reliable model would you say? - The ECM is only updated every 12 hours so surely it's less reliable than GFS?

That’s not how it works. If the GFS changes its scenarios every 6 hours and the ECM is more consistent (and consistently accurate) but with half the frequency of runs then the latter is more reliable.

 

That’s not how it works. If the GFS changes its scenarios every 6 hours and the ECM is more consistent (and consistently accurate) but with half the frequency of runs then the latter is more reliable.

I believe validation has shown the ECM generally to have a slight edge on the GFS if you compare runs with the same starting time. I suppose an open question is whether the extra 6 hours data that the GFS 06Z and 18Z have over the ECM 0Z and 12Z makes them more accurate if you compare them.

 

That’s not how it works. If the GFS changes its scenarios every 6 hours and the ECM is more consistent (and consistently accurate) but with half the frequency of runs then the latter is more reliable.

Right so for now this weekend there is good agreement in mods for colder weather to return.

 

I believe validation has shown the ECM generally to have a slight edge on the GFS if you compare runs with the same starting time. I suppose an open question is whether the extra 6 hours data that the GFS 06Z and 18Z have over the ECM 0Z and 12Z makes them more accurate if you compare them.

Yes, that’s a fair question. Although the same could probably go for the other models that are issued 4 times a day. Observationally (with no statistics at hand to back it up) I would suggest that even with an extra couple of runs a day the GFS op runs rarely get a “head start” on the ECM runs.

 

Have you got the height anomalies? Those charts are ppn and temp.

Sorry Neil - I don't - I only had this bookmarked to my favorites and thought of having a look.

Meanwhile - i see the Daily Express saw the 12z Operational run:

Dr Claire-Kennedy Edwards??

https://www.express.co.uk/news/weather/1388636/UK-Snow-forecast-weather-warning-met-office-snow-charts-winter-ice-London-weather-latest?fbclid=IwAR2ikQIltS8GNpvqJhlmPkI83_g3xDWpigGD4CtmSmOTIJ4qkxFlOQ2ufhY

What happened to their 20" of snow?

 

Yes, that’s a fair question. Although the same could probably go for the other models that are issued 4 times a day. Observationally (with no statistics at hand to back it up) I would suggest that even with an extra couple of runs a day the GFS op runs rarely get a “head start” on the ECM runs.

For me I personally think the ECM twice a day is more consistent. I find 4 updates a day to have wild fluctuations and ultimately eventually returns similar output to those which run x2 a day

That’s not to say there aren’t many examples where this is wrong but on the balance of probabilities I don’t think 4 runs a day are required?

Para's doing it's best to save the situation.....

Of course, the easterly is now a South westerly on the GFS 18z🤣

I knew the 18z would swing mild - or even worse the exact opposite. Getting a bit of a deja vu now me thinks with flip flopping this even 06z showed a northerly post 300z, the 12z showed an easterly with scandi High post 300z with low pressure over southern Europe and most recently the 18z showed a south westerly post 300z with high pressure over southern Europe? What next for the 00z run? We have seen every possible scenario from azores high, northern blocking, to barlett high - just couldn't make it up could you!

I guess the Express would have to re title their front page to "Heatwave to approach the UK"

At least the 18z Op was a milder option of the GFS Ensembles. The para and control has potential - Control shows an easterly post 300z. 

GFS Control pretty eye catching too, and the GEM is still showing a cold outcome - so anything past 144 hours is speculation right now: Clearly eye candy runs are still plausible because they keep popping up, so, as they say, we will see: Feb has promise.

 

I knew the 18z would swing mild - or even worse the exact opposite. Getting a bit of a deja vu now me thinks with flip flopping this even 06z showed a northerly post 300z, the 12z showed an easterly with scandi High post 300z with low pressure over southern Europe and most recently the 18z showed a south westerly post 300z with high pressure over southern Europe? What next for the 00z run? We have seen every possible scenario from azores high, northern blocking, to barlett high - just couldn't make it up could you!

I guess the Express would have to re title their front page to "Heatwave to approach the UK"

At least the 18z Op was a milder option of the GFS Ensembles. The para and control has potential - Control shows an easterly post 300z. 

The forecasters are struggling to figure out the Northerly progression of the milder air over the next few days, so predicting what's going to happen in 7-10 days time in the current set up is extremely difficult. 

Small tweaks in the set up in the short term could lead to significant differences down the line. I would be sceptical of the MO output beyond 3-4 days at present. 

 

I knew the 18z would swing mild - or even worse the exact opposite. Getting a bit of a deja vu now me thinks with flip flopping this even 06z showed a northerly post 300z, the 12z showed an easterly with scandi High post 300z with low pressure over southern Europe and most recently the 18z showed a south westerly post 300z with high pressure over southern Europe? What next for the 00z run? We have seen every possible scenario from azores high, northern blocking, to barlett high - just couldn't make it up could you!

I guess the Express would have to re title their front page to "Heatwave to approach the UK"

At least the 18z Op was a milder option of the GFS Ensembles. The para and control has potential - Control shows an easterly post 300z. 

Just a glance at the model verification stats would tell you that accuracy starts to fall away quite quickly beyond 5 days. At 10 days and more the operational runs are generally pretty useless.

 

The forecasters are struggling to figure out the Northerly progression of the milder air over the next few days, so predicting what's going to happen in 7-10 days time in the current set up is extremely difficult. 

Small tweaks in the set up in the short term could lead to significant differences down the line. I would be sceptical of the MO output beyond 3-4 days at present. 

 

They were still changing their forecasts for Sunday’s snow just 12 hours before - and still got the detail wrong!