Tamara

Hm you are barely 30 miles from me Enjoy

Last Feb there was over 10cms of quite powdery snow here in a situation not too different to this one and a line from Hove eastwards had upper temperatures that decreased very quickly as one went further east. The temperature here actually fell during that snowfall a couple of degrees below freezing. Back then the sea was a fair bit colder than now and also the continent was exceptionally cold which kept dewpoints lower, even though the wind was blowing straight off the sea. I doubt though for east coast regions on Monday the sea factor will come into it as the wind will not be onshore and the coldest air will be in situ away from the slightly milder air.

The further outlook next week supports the cold weather to continue for our region - that suggests that the colder model outputs suggested this morning is supported rather than any faster breakdown as suggested by the ECM. So chances for further snow showers off the North Sea

There is nothing marginal about the METO Tuesday update for sure - as fully expected Its going to turn very icy and slippery by then

I think it is a sensible advisory tbh at this stage - even if we would prefer it to be better obviously. However, bearing in mind it is only Saturday, and the advisory goes up till the end of Monday, I am sure that further advisories, and indeed they mention provisonally amber warmings, will be issued. Especially I think as we get closer to Tuesday when things could get very interesting

Signature done . The wintry element to the rain was in some much heavier precipition. Its back to steady lighter cold rain again

On a separate note for today - the rain is trying to turn to sleet here now

The latest update for Monday by the METO indicates the uncertanity of things and how marginal it could be: An area of sleet and snow will come eastwards across England during the early morning, probably becoming light and patchy later in the morning as it slows down over eastern areas. However, later in the day it is expected to intensify again, at the same time turning back to rain in places. Through the day there is the risk of 5 cm accumulations in places, and more than that above 200 m. However, there is greater than average uncertainty at this range, especially in the extent to which snow affects southern counties, and it is quite possible that the Alert will be upgraded to an amber Warning if confidence increases. The public are advised to monitor the forecast and to be aware of the risk of disruption to travel.

I think that the NAE will be a more reliable guide to details once it comes into the 48hr radar. Atm, it goes out till 6am Monday and shows some light snow arriving. Its through the day on Monday where we will start to get an idea of how temps/dewpoints progress and the precipitation etc. I would trust that information over the GFS charts.

We will have to wait and see, it's still early yet - but indications are that coastal areas might see a little snow to start and then some marginal conditions for a while before better conditions follow again. The charts for first thing Monday look good - it is through the day and most especially the afternoon where conditions might be less favourable, before improving again through the evening. Still every chance of a covering by Tuesday though

I don't think it is all lost by any means - there is every chance that as the feature crosses the region and the temperatures and dewpoints drop back, then snow is very likely. Plus there is good evidence of snow showers following to our region after the main band, as a cold upper pool of air comes in from the North Sea (sub -10) and that will trigger snow showers which could give some good accumulations - and no marginality at all there. We look well placed for that

The GFS suggests a little snow to start with and then temperatures climbing a little later close to the coast - very probably an onshore wind for a time. If you believed the GFS it would suggest probably little or no snow close to the coast - but it is not the most reliable source to use. However, I think that the channel will create problems with dewpoints - at least for a while before the onshore wind is cut off. The NAE out to 6am certainly suggests light snow at that stage with upper temps around -8C. Its what happens after that - the next update will give better indications.

I remember that well - there was already deep snow and I went to clear my car which was parked at the top of the road (I live on an incline so thought that it might avoid a wrong *drivers moment* being parked on level terrain) and the snow that night you mention at the start of December suddenly began falling really heavily in thick flakes and by the time I had finished clearing one side of the car, the other already had a few cms fresh cover over it. Suffice to say I gave up and just a few hours later a good extra 15cms of snow had fallen Nostalgia aside the conditions on Monday and Tuesday certainly won't be anything like that, but nonetheless away from the south coast the conditions should be good enough in my humble opinion to support a good snow cover

The wind direction makes quite a difference - atm it is blowing offshore. We do best with a snow shower north easterly coming from the North Sea rather than weather fronts from any point of the atlantic. There are good signs we may just get that next week

Winds will initially be onshore for anyone living close to the coast on Monday - so snow might not be possible till this is cut off as the low passes across the region. The channel could well be a spolier as sea temperatures are relatively high for this time of winter due to the mild weather recently. This will keep dewpoints higher till the onshore wind is cut off. However into Tuesday it looks a lot better and the snow might be slow to clear - so anyone near the coast may well make up for lost time then Plus it looks like there could be a lot of snow showers afterwards anyway

Those AO/NAO correlation with SSW studies are very interesting wrt to the current tropospheric representation of the SSW we have of the here and now. Pertinent completely to the GFS vs Euro model differences in terms of undercutting energy or stronger push in the northern arm of the jet, making the difference between a - or + NAO. If we assume an -NAO lag period as suggested above, then there is indeed some case for the most favourable NAO response arriving late in the month and into February which will assist in backing the displaced cold air from the pole further and further south and west - much as expert opinion suggests. Especially as further warming is suggested on stratosphere forecasts to help perpetuate a virtuous (cold blocked) pattern further into the remainder of winter. In that respect any (relative) interim cooling at the higher 10hPa level should act as a favourable squeeze for lower propagation of warmer layers down towards the troposphere - with the cycle repeated as another top warming, as forecasted, is applied. That is the theory anyway

Assuming that the Azores High is correctly modelled the way that the operationals all suggest tonight, then the chances of a cold spell are very much increased and extended. We get the southwards disruption of the lower heights to the north and pressure then rises above it to the north over Iceland and Greenland.

You can't make up fixed rules about weather patterns - each one has to be taken and assessed on its own merits using the best available model output and data that is available at that given time. This is a continually moving programme, continually subject to change. The current pattern evolution, and potential avenues that the pattern may take are rife with uncertainties with the atmosphere in such flux over the polar stratosphere field. On that basis the process of using best available data at a given time takes on a higher level of necessity than usual. Of course weather forecasting always has this requirement 24/7 - it is just that predicting the way forward in such a set-up as this is a permanent updating 'now-cast' on the biggest of usual scales! No wonder we get an insight into the head scratching that is going on at the METO - not an enviable task with so much model chopping and changing and lack of agreement The GFS alludes to a progressive -NAO scenario as head through the rest of the month - this fits the predicted background pattern and would also plausibly also fit any less cold interlude that the ECM may allude to as well, as polar vortex energy is transported across the pole from Canada to Siberia.

SK update:That sounds a lot like deja vu and the sort of pattern we have seen through many recent months back to the summer, with blocking to the north or north west, but low pressure close by, or over the UK, without any polar easterly/northerly airsteam advecting south of the country - so effectively cutting off Arctic air as low pressure on the jet stream attempts to disrupt across the atlantic but never properly gets south enough deeper into Europe

I would like to add my thanks for that post from SK as I have no quota of 'likes' left for usual silent appreciation. Explained very logically, very thoroughly and in simple understandable terms for us ordinary folk