phil nw.

A nice frosty scene still at 11am. The Cirustratus has spread in here too. It has been a lovely little cold spell with great walking weather. If I can't get the snow this is a good second best as it does feel seasonal. The longer this high holds the better keeping the worst of the Atlantic wind and rain away.

Just looking shorter term at the latest operational runs and there is still disagreement on temperatures for next week. It looks pretty dry for most away perhaps from the far north but any milder weather may well be hindered by the movement of the high especially further south east. GFS and ECM want to return the cold uppers by day 6 as the high is moved far enough west as it topples to get a north easterly.We can see the ukmo run is modeling a more rounded high and holds it closer to the Uk and therefore has the less cold air around. it will be interesting to see if the milder westerlies even get in by week 2 as this stubborn high may hang around far enough north for longer. In view of the uncertainties with the warming affects of the Strat. on the trop. pattern i am not taking to much stock of the later ens guidance.Looking briefly at the eps postage stamps for day 10 show the high never far away.Latitude shown is around 50n.give or take,but it's exact position and orientation is still to decided.The centre could be anywhere from mid-Atlantic to Scandinavia which has a bearing on our surface conditions. Original post: https://community.netweather.tv/topic/98196-model-output-discussion-new-year-and-beyond/?do=findComment&comment=4794785

Just looking shorter term at the latest operational runs and there is still disagreement on temperatures for next week. It looks pretty dry for most away perhaps from the far north but any milder weather may well be hindered by the movement of the high especially further south east. GFS and ECM want to return the cold uppers by day 6 as the high is moved far enough west as it topples to get a north easterly.We can see the ukmo run is modeling a more rounded high and holds it closer to the Uk and therefore has the less cold air around. it will be interesting to see if the milder westerlies even get in by week 2 as this stubborn high may hang around far enough north for longer. In view of the uncertainties with the warming affects of the Strat. on the trop. pattern i am not taking to much stock of the later ens guidance.Looking briefly at the eps postage stamps for day 10 show the high never far away.Latitude shown is around 50n.give or take,but it's exact position and orientation is still to decided.The centre could be anywhere from mid-Atlantic to Scandinavia which has a bearing on our surface conditions.

Even without a full blown technical ssw It looks like we are starting to see the effects of a weakening spv showing in the later frames. I would think the slowing down of zonal winds and the coming spv displacement will eventually create more gaps in the 500hPa pattern over the Arctic. The immediate outlook of a UK high is not a bad place to be whilst we wait to see if we can benefit from the warmings above. Original post: https://community.netweather.tv/topic/98196-model-output-discussion-new-year-and-beyond/?do=findComment&comment=4793519

Even without a full blown technical ssw It looks like we are starting to see the effects of a weakening spv showing in the later frames. I would think the slowing down of zonal winds and the coming spv displacement will eventually create more gaps in the 500hPa pattern over the Arctic. The immediate outlook of a UK high is not a bad place to be whilst we wait to see if we can benefit from the warmings above.

Lovely day here.Crisp Winter sunshine after -4c overnight. Love this weather for walking in, second only to a snowy landscape. I am well sheltered here from showery activity and miss those snowy easterlies of the past.

Yes you have pretty much summed it up Bricriu. We need a 2 wave attack on the strat.vortex to squeeze into it from opposite sides. At strong enough event will find the pinch point and split it . A wave 1 attack will,as you suggest, create a displacement and can push the spv off the pole. We are seeing forecasts for such a displacement currently. How this affects the troposphere is still to be decided at this stage.

John let's wait and see the trends in the models.As i am sure you are aware forecasts continually change and this applies to the Met. as well.

There is also this for your perusal snowray There have been postings and updates in there today.

Yes a displacement is never as good as full blown split. Not sure how much mileage we will continue to get from the current wave 1 warming before as you suggest the spv looks to return to it's home. Looking at the latest forecast of the new mjo cycle doesn't hold much promise for any tropical help later on.This can change of course but i can appreciate your concern that the next week or so could be crucial for any further cold pattern to develop before we start to lose the coldest(supposedly) part of the year

Clear signs of reversal of zonal winds in the coming days forecasted almost down to 10hPa Indeed a dramatic weakening of the vortex is showing with negative anomalies filtering down. On going wave 1 action continuing to month end which eventually pushes the spv off it's polar perch. The trend of a weakening of the vortex looks like continuing and with the ongoing wave 1 warming this will continue with a spv displacement off the pole and the decrease of zonal wind speeds. The unknown of course is how this plays out lower down at the 500hPa level but if nothing else it keeps the Atlantic jet weaker and amplified so increases chances of colder air spilling into mid-latitudes.As ever we need that bit of good fortune to get it here in the Uk.

Nice little change on some of the models today showing a building of heights around Scandinavia. Signs of a weakening Atlantic and once we see that stalling then it can cool down quickly under a continental flow of drier air and low dew points at this time of year. Let's see if we can get an easterly out of this further on as some of ensemble members show.

Quite a messy picture in the next few days as the low crosses the Uk and drags in the cold air behind it.Looking at a couple of fax's we see a number of fronts and wave developments heading down in the cold north west and then northerly flow. The Arctic air established pretty much countrywide by Monday.No doubt some locations will see snowfall but as ever more than a day or so out tricky to forecast where and how much.Even the short range models vary on this. Looking at the daily temperatures next week it like being the coldest period since early December with max's further north around zero and low single figures elsewhere.Sharp night frosts expected. The Warks.ens show the change to cold. Looking ahead current outputs favour a pressure rise towards the weekend with cold upper air being pushed away.As can be seen on the graph some recovery in daytime max's towards average are showing. EPS day 10 Currently favouring the high near the south with milder Atlantic air across the north. Where this goes beyond remains to be seen.With later mean anomalies showing ongoing Scandi.ridging we can never rule out this building west as zonal winds continue to reduce. Warmings continue above and these may come to our aid just as the effects of the last mjo on this side of the hemisphere die away. One good thing is that this current low looks like it's the last one to affect us for a while as it heads away towards Norway early next week.Thank goodness after all the rain we need a break. Original post: https://community.netweather.tv/topic/98196-model-output-discussion-new-year-and-beyond/?do=findComment&comment=4789173

Quite a messy picture in the next few days as the low crosses the Uk and drags in the cold air behind it.Looking at a couple of fax's we see a number of fronts and wave developments heading down in the cold north west and then northerly flow. The Arctic air established pretty much countrywide by Monday.No doubt some locations will see snowfall but as ever more than a day or so out tricky to forecast where and how much.Even the short range models vary on this. Looking at the daily temperatures next week it like being the coldest period since early December with max's further north around zero and low single figures elsewhere.Sharp night frosts expected. The Warks.ens show the change to cold. Looking ahead current outputs favour a pressure rise towards the weekend with cold upper air being pushed away.As can be seen on the graph some recovery in daytime max's towards average are showing. EPS day 10 Currently favouring the high near the south with milder Atlantic air across the north. Where this goes beyond remains to be seen.With later mean anomalies showing ongoing Scandi.ridging we can never rule out this building west as zonal winds continue to reduce. Warmings continue above and these may come to our aid just as the effects of the last mjo on this side of the hemisphere die away. One good thing is that this current low looks like it's the last one to affect us for a while as it heads away towards Norway early next week.Thank goodness after all the rain we need a break.

Many of us have been enduring this zonal spell hoping for a mid-month change and right on cue the models are showing a colder week next week. Gefs mean 850s for days 1-5 and 6-10 show a big change over the uk and nw Europe. Polar air directed south squeezed between the Russian heights and a mid-Atlantic ridge. It looks like quite a few cold days with the best chance of seeing snowfall more widely since early December i would think.Scotland favoured but with probable disturbances spinning south from the Iceland area in the cold unstable flow snow anywhere can't be ruled out at this stage. Considering the fairly weak mjo this time round we are probably getting the best from this upcoming pattern with modest ridging and a deep Euro trough working in tandem to get this cold so far south.

Although the GFS is in the naughty corner wrt micro differences with the other models I have to say the overall pattern is still essentially a +ve nao. Not conducive to blocking and still Atlantic driven for the foreseeable. Zonal wind forecasts do trend down from mid month but only a small minority of members heading for a reversal. This trend shows up with a more wavering jet pattern which increases the chances of more polar maritime air coming into play in the coming days. I don't see anything out of the ordinary for January in current nwp though. Wave 1 warmings continuing and still look likely to displace the Strat polar vortex but it is a case of waiting to see how this affects the 500hPa pattern.

There is still warmings going on with the continuing wave 1 action on the vortex showing the spv being pushed around and squeezed. but that very cold core looks hard to penetrate with model runs all showing the wave surfing around the edges pushing the spv off the pole. So really nothing dramatic within forecastable time frames other than a very gradual downturn on zonal wind speeds at 60N as the wave 1 warmings continue. The gradual easing on zw speeds are more noticeable in week 2 with the extent of -ve anomalies growing through the levels.This may produce a more amplified 500hPa pattern if this trend continues but these forecasts i found at that range do vary. In summary some action but not a lot to hang our coldie hats on in the next couple of weeks.Unfortunately there is no sign of any strong wave 2 action to induce a split or knockout blow at this stage ,only a displacement.

I think we are looking over the horizon so to speak for any pattern change. Zonal winds are currently at their peak and will fall away soon with forecasted spv displacement looking likely as wave 1 attacks continue. This will eventually show up in nwp outputs with the jet slowing and becoming more meridional. The MJO could do us a favour here but it is a waiting game while we we wait for any reduction in vortex strength to flush down to the surface. Original post: https://community.netweather.tv/topic/98196-model-output-discussion-new-year-and-beyond/?do=findComment&comment=4783082

I think we are looking over the horizon so to speak for any pattern change. Zonal winds are currently at their peak and will fall away soon with forecasted spv displacement looking likely as wave 1 attacks continue. This will eventually show up in nwp outputs with the jet slowing and becoming more meridional. The MJO could do us a favour here but it is a waiting game while we we wait for any reduction in vortex strength to flush down to the surface.

I wish everyone a happy and healthy New year. I think we have a great community on here and I appreciate all the knowledge and friendship that has developed. I hope the ongoing wave action on the vortex will bring us all a snowy outcome.

Zonal winds currently chugging away merrily up top with some of this uptick now driving the NH trop pattern. Some easing off expected mid-term at the top before another increase later.Lower down t signs of a slow down(blues) with just tentative hints later in week 2 that a fall off of zonal winds may occur. Still forecasts of continuing wave 1 action on the vortex into mid-month which looks like displacing the strat vortex off the pole. So just little signs of some reduction of zonal winds nearer the surface and signs of vortex displacement so chances of the jet flow becoming more disrupted as we go into week 2.It is of course in the lap of the gods how this will re-shape the 500hPa pattern.

Looking at the gefs 06z next week may be too soon but a look at later week 2 shows quite a bit of interest. Azores high ridging ne and cold air approaching from Scandinavia,maybe a trend to follow with timing fitting in with the mjo lag.Whether it fully establishes linked probably to the mjo amplititude.

From scanning the day 10 eps stamps the colder pm incursions seem the best hope of anything wintery mainly for Scotland. Slim pickings really for any other options than mobile westerlies.About 8/9 efforts of Scandi ridging but many more with a high close to our south west. At least it will allow for some north westerly flows especially if the high retreats west occasionally.Now if we do develop more amplification in the jet then this would make things more interesting.

Yes typical Atlantic pattern for mid-winter,colder air more prominent in the north with good chances of snowfall. Gefs 2m temp anomalies for the next 5 days A bit of a north/south divide for us but Just look at toasty Europe though.Large areas 10c above average!

Talking of a warm Europe i just thought seeing these images might sum things up for the coming days , these from the gefs First days 1-5 overall mean 2m temps. You could say mainland Europe is under blowtorch conditions going into the NY.Note the warm up for much of the states too. Secondly and nearer home fairly mild for us generally too but the exception being the far north often just inside the boundary of the polar air as can be seen by the 850s. Compared to here in Warks we can see the difference north to south. Overall a solid +ve NAO pattern with the warmth again back into mid-latitudes and the cold bottled up further north for the time being at least.