Ben Sainsbury

Yeah GFS always overplays the possibility of snow, we can always hope!

Those looking for snow within the next few days, there is some hope for the night of New Years Day, the colder uppers edge their way in a little quicker and the front seems to slow its why southwards.

I don't think the accuracy of the model is determined by how far out they go, doesn't make much sense?

GFS 12z positioning of the High very nice, retrogressing west towards South Greenland, some big differences still.

I think the High sat in the Atlantic on the 6z has a better orientation allowing Northerly winds to take hold quicker, I think on the 12z this is going to take a little longer.

They don't want to put it out there so quickly as we know how unpredictable our weather is.

Good consistency up to T69 so far, -5 850hpa's over the majority of the UK at this point bar the SE.

As a matter of fact the GFS 18z hints at the front stalling during the early hours of 2nd Jan over Southern Britain.

Not to get any hopes here but I think we're forgetting about the "marginal" snow event that could take place on the evening of New Years Day. As a matter of fact this event has been consistently modelled over the last few days so definitely something we should keep on eye on. However marginal events like these are extremely difficult to predict even 3 days away. This event really depends on the timing, the sooner we can -5 850hpa temps the better, but then the closer we move towards night the colder the temps. Something to keep an eye on anyway. The first set show the 850hpa temps and precipitation type on GFS 6z: This next set shows the 850hpa temps and precipitation type on GFS (P) 6z: And as bobbydog has just indicated the GFS has support from GEFS members too. What timing to post at the same time! aha

Anyone have an idea or suggestion for why the High seems to track towards the UK at T144, when there doesn't seem to be much energy of Eastern US/Canada?

Can you please explain what you mean? It would be valuable to those who want to learn and myself!

Fair point, but I think people who are talking about downgrades are unclear, there are no downgrades in regards to the possible temperatures we may receive. I think the downgrades people are talking about are in regards to the lengthliness of the cold spell.

Beat me to it... Just

GFS 12z looking much better on this run. You can see the high sitting further west over the Atlantic. Amplication better too as stretching up to Greenland. As the high has a better tilt the winds sit more NE than E bringing the risk of snow showers, possibly colder too. Good consistency I must admit. 12z at 168hr: 6z at 174hr:

What is positive to note is for a 10 day spell from 1st Jan to 11th Jan the majority of the runs don't reach >0 850hpa temp bare a small few. Being in London this is something we haven't seen for a while.

Just had a browse of the 0z ECMWF, and check out Wednesday 14th/Thursday 15th... Given the extreme temperature contrasts, I'm not surprised it has deepened so quickly! Some drop of possibly 40mb in 24 hours. Now that is some "Explosive Cyclogenesis"

True nevertheless, but given the setup last year we were far more prone to mild wet weather than this year. Given the unpredictability of this year and the backing of something colder in general we "hope" to see this brief mild spell not so dominant as last year.

Being on such a small localised scale, I don't think it would effect our side of the world. (Thinking back to latest Iceland Eruption). Would cause some localised changes in weather possibly, decreased temps etc. And anyway I assume models wouldn't take into account factors like that anyway.

Specifically why I posted this given the turnout of December 2010, not sure how the charts proceeded from there tho.

Talking about UKMO having a deeper sliding low, aren't we used to the GFS overdoing how deep low's are? In that case we may see further corrections from GFS?

In my personal opinion, 10th December 2010, and forecast for 2nd December 2016 look markedly similar? We all know how end of December ended;) Just my amateur perspective of course!

What do we need for the High over us to push NW?

I think now we can hope for the GFS to make small steps, given the energy being split in this latest run compared to the last even though the end result is still meh. At least the consistency between the runs is still there. (Comparison of GFS and UKMO)

967, lower than what most models have suggested?

Yeah Bristol Channel, always fuel these sharp showers got a couple of pictures today too!