Can someone point me in the direction of what Steve is talking about then from that UKMO chart ? Again the below -

 

• Cold air not in place when the systems arrive.


• flow turns West of South when system arrives - needs to be East of South.

Both or 1 of those parameters need to be in place for at least a temporary snow event (away from the highest ground) and they are not on any of the NWP I've seen this morning.

 

I’m inclined to agree Ian. 

 

Can someone point me in the direction of what Steve is talking about then from that UKMO chart ? Again the below -

 

• Cold air not in place when the systems arrive.


• flow turns West of South when system arrives - needs to be East of South.

Both or 1 of those parameters need to be in place for at least a temporary snow event (away from the highest ground) and they are not on any of the NWP I've seen this morning.

 

Not without interest for some, I would say.

 

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I don't know why it is showing snow when  the parameters are not there from it's own data - possibly for the highest ground ? Perhaps someone could explain. Darren ?

 

Thats the point, it is showing snow because the parameters are there. That’s the way the models work, it’s not as if they think for themselves!

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I think we can all accept that from midweek the parameters could go either way - a small swing and you move from all rain to a heavy snowfall. The various model outputs will also reflect this in their ppn projections - inter-model and inter-run.

Cherry picking is not really sensible in these setups at this range (IMO)

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I think we can all accept that from midweek the parameters could go either way - a small swing and you move from all rain to a heavy snowfall. The various model outputs will also reflect this in their ppn projections - inter-model and inter-run.

Cherry picking is not really sensible in these setups at this range (IMO)

👍🏻

I think we can all accept that from midweek the parameters could go either way - a small swing and you move from all rain to a heavy snowfall. The various model outputs will also reflect this in their ppn projections - inter-model and inter-run.

Cherry picking is not really sensible in these setups at this range (IMO)

Yes you are right Neil and my point is not that the last couple of ECM runs showing snow is the likely option merely that is an option. 

It will be an interesting few days coming up. 

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Can someone point me in the direction of what Steve is talking about then from that UKMO chart ? Again the below -

 

• Cold air not in place when the systems arrive.


• flow turns West of South when system arrives - needs to be East of South.

Both or 1 of those parameters need to be in place for at least a temporary snow event (away from the highest ground) and they are not on any of the NWP I've seen this morning.

 

 

If after all these years you still cant read a chart & understand what it shows then there is no point in even helping you.

UKMO raw would have an area of snow from London / essex up through to the midlands. All north of the boundry.

ECM RAW - showing heavy snow across england @168...

GFS 0z with a differentish evolution as we move into FI, with a GH ridging southwards into the mid-Atlantic, and a huge area of slack low pressure over Scandinavia. Gives us a coldish northerly flow followed by a messy breakdown that gives an outside chance of snow around Xmas (but the Op is one of the coldest evolutions and tge GEFS snow rows are poor). Its an unsettled picture throughout, even in the south.

ECM tries to get energy sliding SE'wards twice in the run but doesn't really manage it and it's messy throughout. But there is a lot blocking to our north, strengthening as the run progresses, which will hopefully extend southwards to affect more and more of the UK, with lows forced onto a more southerly path.

All in all not very festive in the run up to Xmas, but not actually a million miles away and, if like Steve Murr and some others believe, the outcome evolves only a bit differently and energy does move SE'wards instead of driving away the fledgling block to our E/NE, we could get much better conditions.

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Have to say, fascinating model watching. Next week still far from decided and further out much to be excited about with upper atmosphere events. This is going to be a great winter for model watching me thinks Short term trend for me tho is edging back to white from wet but what a forecasting nightmare lol.

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So, the cold air hasn't made it to the UK, and heavy rain is spreading East on Thursday morning, the flow has turned SWerley -

 

 

http://old.wetterzentrale.de/pics/Rtavn1201.gif

 

 

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So, the cold air hasn't made it to the UK, and heavy rain is spreading East on Thursday morning, the flow has turned SWerley -

http://old.wetterzentrale.de/pics/Rtavn1201.gif

GFS raw ppt type has some sleety snow over Ireland which fits in with this profile.

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ICON 6z also shows the cold air failing to get into the east. Personally I wouldn't totally discount the possibility of a snow event away from northern high ground next Thursday but think you'd need to be barking to put your last £ on it happening.

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Very mild and wet next Saturday morning on the GFS -

 

http://old.wetterzentrale.de/pics/Rtavn1681.gif

 

 

 

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With rising river levels there will be less room under the bridges.

A messy but finely balanced picture once again on the GFS op run.

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So, the cold air hasn't made it to the UK, and heavy rain is spreading East on Thursday morning, the flow has turned SWerley -

 

 

http://old.wetterzentrale.de/pics/Rtavn1201.gif

 

 

Yes and there's not much sign of the blocking holding firm to our East. In fact it sinks away into southeastern Europe pretty quickly on the 6z leaving the UK in an Atlantic dominated pattern. I'm with you on this Ian. I honestly can't see what Stev Murr is seeing at all.

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Yes and there's not much sign of the blocking holding firm to our East. In fact it sinks away into sputheastern Europe pretty quickly on the 6z leaving the UK in an Atlantic dominated pattern. I'm with you on this Ian. I honestly can't see what Stev Murr is seeing at all.

Was Steve talking about the (06z) GFS op output? I thought he was referring to the UKMO and ECM? 

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FWIW here is the ECM snow line chart for Thursday evening

18Z Thursday - snow line at no more than 200ft for some eastern areas

https://weather.us/model-charts/euro/england/snow-line/20181213-1800z.html

Freezing level is around 800ft at best

https://weather.us/model-charts/euro/england/freezing-level-feet/20181213-1800z.html

3 hour precipitation chart for the same time

https://weather.us/model-charts/euro/england/precipitation-total-3h-in/20181213-1800z.html

Very marginal but worth keeping an eye on. Could be a covering of snow to higher ground. But would only be temporary.

Yes and there's not much sign of the blocking holding firm to our East. In fact it sinks away into southeastern Europe pretty quickly on the 6z leaving the UK in an Atlantic dominated pattern. I'm with you on this Ian. I honestly can't see what Stev Murr is seeing at all.

  - flooding becoming an issue if this run comes off, a really dreadful pattern and as shown on the ECM, signs of a West based NAO with pressure rising over Europe by day 10.

 

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FWIW here is the ECM snow line chart for Thursday evening

18Z Thursday - snow line at no more than 200ft for some eastern areas

https://weather.us/model-charts/euro/england/snow-line/20181213-1800z.html

Freezing level is around 800ft at best

https://weather.us/model-charts/euro/england/freezing-level-feet/20181213-1800z.html

3 hour precipitation chart for the same time

https://weather.us/model-charts/euro/england/precipitation-total-3h-in/20181213-1800z.html

Very marginal but worth keeping an eye on. Could be a covering of snow to higher ground. But would only be temporary.

Here is the snow depth chart (for England) for Saturday morning on the same run https://weather.us/model-charts/euro/england/snow-depth/20181215-1200z.html 

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