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Actually getting interesting again from a coldie perspective as the models continue to track the jet a bit further south and lower heights look to become dominant across w Europe in general the last two ec op runs have delivered snowfall across s half uk (whilst the north receives some thing via cool zonality) as said by many previously, s tracking jet and a cold Atlantic trough will send runners along the base of the trough. Early Feb is not a terrible time for snowfall though sustained isn't supported by such a mobile set up - however, clearly Exeter are seeing something on glosea re ramifications by mid month from events high up and whilst that day 16 GFS chart is not going to verify like that, it must have some background pattern support for derek to tweet it. feb has never looked like delivering much and yet we may be surprised !

wasnt really asking, more of a statement

Well the chase for cold and snow continues, a bit less frantic than before I had my holiday. In truth perhaps rather more chance of passing deepish cold than then! Why? Well with a reasonably mobile Atlantic, some quite deep surface lows, passing not too far from our northern shores thus giving some cold outbreaks on their western side. Of course the NW'ern areas will fare most from this, and at long last the Scottish ski areas might get some trade. It must have been one of the worst seasons, so far, in a long long time for them. As each low passes then the deepish cold I mentioned may well penetrate well south. So the higher ground from N Wales and the Peak District could see temporary coverings of 24 hours or so from this pattern. Maybe a few flakes on low ground further south. more interet for weather fans than the past few weeks. I managed a mean of just 2.0 C over the 8 days I was away. The coldest spell for a couple of winters I think. Looking at the inevitable anomaly charts below and the 500mb flow shows what I mentioned above on all 3. http://www.cpc.noaa.gov/products/predictions/610day/500mb.php and the 8-14 shows a similar pattern http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html Beyond two weeks, not my area of experise so I will leave that for others.

There are more promising signs of a wave2 development on the 06Z GFS - that would be the first step to get a better pattern above and then rely on this being reflected further down. from this to this At first glance, it may seem as if the core vortex is setting up in the worst possible location but there are plenty of historical situations where this has worked out well if a proper split occurs - simply because of the suggestion from Ed (I think) that the jet does not cross the split.

The GFS 06hrs run has a semi-tease with that high pressure over Scandi but with the PV lobe located over east Canada will have no chance. The lack of amplitude upstream just puts too much pressure on that high with the energy piling mostly ne. The ECM does have some shortwaves running east along the base of the trough which might give something wintry on the northern flank but too far out to put too much faith in. Any interest doesn't really arrive till after day 7 and its marginal, any shortwaves that do form you'd want to be weak and not deepen, that would increase any wintry potential. It's really at the moment trying to scrape some interest until we see a change upstream, all our eggs are really in the strat warming weakening the PV and the MJO together working to bring about a change to the NH pattern to help deliver a better chance of some snow and deeper cold.

Oh!!!,here we go 10 & 30 hpa

There's not a greenland high there I'm afraid. You'll often see a surface high over Greenland because of the cold air, but for a Greenland high in the proper sense of the word, you need to see the yellows and oranges on the 500hpa height charts.

A bit of a contradiction that one, as you note the SE has had the real cold period, yet compare that with the CET - which to those who may not know is the Central England Temperature series. You need to compare apples with apples. In terms of the models, the GFS ensemble anomalies show a pretty clear-cut picture, and that's the weakening of the block and the dominance of low pressure through much of the run. The ECM similar, so broad agreement currently.

Only 384 hours away

Heavy snow up here and all white

Why not simply say what it is?

Lying up here

Theres no law in this thread saying we have to use only standard terms. We've had lots of new terms pop up including Sceuro high etc, loco zonal sounds perfectly fine to me. I think its pretty evident, zonality for the UK but not blasting well into Europe.

The ensembles are excellent wrt long term though, the blocks are being built. Regarding the shortwaves - yes you want them to be shallowish at surface level but you still want low heights so thicknesses are low, I always look to the area in between the main troughing and the shortwave in those setups where the calmer conditions might give evaporative cooling a chance.

Derek is an excellent meteorologist too, very good forecaster and so a tweet worth keeping in mind B FTP

I am a bit more encouraged by the 12z EPS z500 mean this evening, with a ridge west from Scandi toward Greenland at day 10 and it's still there and still prominent days 11-15 too. Which could indicate tentative signs that the displaced sPV may be altering the height fields to our N/NE with time, though the displacement is initially responsible for ramping up the Atlantic for at least a week and probably more, though at the same time shifting the jet south. More runs needed for a trend, but the ridging to the NE, although too far away to keep the Atlantic at bay form us, will help create wave propagation up towards the strat, perhaps an increase in wave 2 activity.

I know that these charts are right out in FI but if something favourable shows up for a couple of days on the GFS there is a chance that it could be brought forward a bit and other models might come on board. After all this SSW must be having some effect on the PV by the 2nd/3rd week of Feb, anyway we don't need the full split vortex to get some cold our way, just some northern block that sets up in a favourable place.

Well at least we are seeing improvements on each run from what we had a couple of days ago.

dampishness

I'm old fashioned Jonathan, so to my way=explain what the chart is showing. 'localised...zonality', to me is a meaningless phrase and I would imagine to a lot of new folk trying to get to grips with model outputs quite confusing. However each to our own idea.

No. I believe it to be user-defined terminology that is little more than gibberish

Yes GFS showing signs of a weakened disconnected PV lobe over Canada as we move out of the first week of Feb, and this would definately encourage an injection of arctic/polar maritime air from a NW/N quarter as being hinted at in its long range output. So all eyes on the strength and position of the lobe over Canada in the coming days, a movement NW is needed to enable colder air to filter our way, and it is very plausible. In the meantime, expect sudden short term developments, just as we have now, with a closed low feature crossing the south of the country, but crucially delaying the chance for milder uppers to invade the north, indeed it now looks like it will be Tuesday before the whole of the UK experiences a milder pattern, and in the north, very brief. Lots of snowfall for the scottish ski centres in the coming week which is good news.

So in other words 'unsettled'. No need for yet another buzz word to be invented.

About an inch up in the Lomonds. I feel a dawn ramble is on the cards before it all melts

Another nasty looking cloud explosively developing north of Heathrow

Been on and off most of the day, melted a bit when temp rose to 1.7C, but now seems to be settling and covering everything again. Hills and fields are still pure white. Sky looks very heavy.

Quite hypnotic watching it falling. Only sleety stuff but was on for a couple of hours. Nice to see all the same! If anyone mentions easterly next season, I think I shall curl up and die!! What a waste of a winter chase.

And there i was thinking it meant crazy zonal.

The best way of looking at the prospects for roughly the next 10 to 14 days is anything wintry is a bonus. The better chance of seeing anything develop is after that point. The NH pattern currently isn't condusive to any prolonged cold or snow. The UK's prospects of salvaging a decent spell are likely to be more towards the second half of February. I'm still optimistic that we'll see some changes and theres a better chance that the MJO could have a greater impact on the NH pattern at that point if it can get into phase 7 and 8. Much of the winter its impact has been muted by continual interference, NCEP expect this interference to lessen, allied with the PV likely to be in a weaker state later into February the odds are more in favour of cold and snow.

Snaw/wintry stuff continued overnight and has given a covering here. Still going, though wet snaw now and a raw, dreich kind day out there. Currently 0.8C/1C.

Much better ridge into Scandy

Best chart in some time though, could be more eye candy to come now that the SSW is starting to get into full swing.

A fellow UK storm chaser, Pete Scott, who's in northern Norway, posted this photo he took of nacreous clouds today on fb:

So Matthew Hugo predicts half of Feb could be wet windy ,no sign of any cold ,right I, m off out of here ,the guy is very knowledgeable but we will have some very cold air to our far north driving this cyclonic wintry spell and if we get lucky we have a good chance of the white stuff ,right I, m back ,don't give up this cyclonic spell could bring us what we desire ,cheers gang .

Just a quick comment regarding the strat and those 10/30 hpa charts that have been posted in the Strat thread that look so impressive regarding a warming. here The warming has been well forecast for at least a week or more now and the (near) SSW (probably now going to be defined as a minor warming rather than a major one, by the met office, because the winds at 60n don't quite reverse) is as we expected. Yes a good warming up there, but not such a good result, a displacement of the vortex is the end result from the warming, and unfortunately the displacement does not look favourable if its a high lat block in our area you are after. A split in the strat vortex would be much more interesting, but alas that is not how the strat pattern is responding to the warming. This summary is based on the initial warming and there "might" be some more developments in the strat as we go forward, but the initial warming, that those impressive looking spiking charts at 10/30 that were posted in the strat thread indicated, are actually just showing the expected spike, which as described does not split or displace the vortex into a favourable position for subsequent down-welling. If i post some charts for reference, You can see that massive warming heading towards the pole, Which is a major departure from what was there before But the end result just displaces the vortex from the pole to the lower latitudes and as stated it is displaced southwards over north Europe, so if your looking for a direct correlation between the strat and the troph its not looking ideal! We then get the second warming (wave 1, we really need to see a wave 2 injection to split things) Which again results in a slightly displaced vortex, but nothing thats screaming a good troph (troposphere) pattern if it was to down-well. So in summary, even though we get a good strat warming the resulting stratospheric pattern in not looking that good for our region if a direct downwelling is to effect us and result in a colder pattern. There is some argument that the displaced vortex may ease the canadian troph PV and perhaps could encourage a colder north west/north flow for us but we shall have to wait and see.

So that sneaky little low is back but about half a day later than once shown, crossing E&W on Sunday afternoon and into the overnight period. This leaves the northern half of E&W under relatively cool air for Monday, compared to the balmy double-digits that was being shown before the small low was reintroduced to affairs. The super-mild air for Tuesday faces more opposition than before, which has a dramatic impact on the max temps for eastern parts; From to This could easily adjust back though, as the small low is shallower on the 12z UKMO, GEM and ARPEGE runs. Still - it goes to show how sometimes it can take almost as little to suspend mild air as it all too often does to do so with cold air 12z GFS goes on to produce too much cyclogenesis in the western N. Atlantic for enough Arctic or polar maritime air to get into the circulation to make things more interesting. Meanwhile the MJO is finally getting a move on, but JMA has lost interest and GEFS is not as keen as it was yesterday. ECMF and UKME remain steadfast and it can only be hoped that they are seeing the true path with less interference from other equatorial phenomena. The ECMF mean is now sufficiently amplified in phases 5-6-7 that some significant and favourable adjustments to the longwave pattern may occur in response, both for getting a colder flow to the UK and assaulting the polar vortex. It's pretty much our last clear hope for the season, but it's shining as brightly as any I've seen these past two months. Or maybe that's just the fact that the line is yellow

Snow, lovely fluffy blizzards of white flakes and drifts of.... ach, drifted off there again, been watching Fortitude too much... Dreich, drizzly pish all day, getting heavier now. Pfffft.

no bored with explaining it

06z GFS continues with the concept of loco-zonal with troughing unable to make inroads into europe. We are thus left in a quasi atlantic airmass. We need troughing to dive into west/west central europe and then we are very much game on. With loco-zonal please expect short term suprises. No double digits today - delays inevitable. Enjoy !

morning all. just read in the strat thread theres been a large spike in the 10hpa temps and the 30hpa temps. surley this is going to begin to throw the models out, im expecting a lot of chopping and changing/flipping and flopping. fromey

Some stormy ensembles - P3 wants to wipe southern UK away next weekend!

Funny how the models always get dreich, damp, drizzle correct!

Dreich damp drizzle Freezing Total p1sh

Tuesday looks very mild for just about all of England and Wales with temps widely in double figures still chilly for the bulk of Scotland

Well I'm guessing the met office are seeing something in the predicted strat warming as their 16-30 dayer now suggests the low possibility of a more prolonged cold spell second half of Feb.. I'm sure that will change again tomorrow though..

Not sure what you are implying. I counted at least five periods of rain crossing the UK between now and D6 so to suggest anything but unsettled is not correct (though the further SE the less impact). We have had this euro block -v- Atlantic before and even when the UK is at the end of the train, wet weather is the likely outcome. Watch the jet to see where the rain will be. Looking at the D16 mean and little change, looks like the move to a different pattern will be slow. The cold uppers are on a poor axis for the UK so with no forcing showing then it will take a while from that D16 chart to get the UK cold: As suggested the ECM D10 chart this morning now in line with the GFS. It is from around D10/11 that the PV can ease away from our NW as the ex EPO High warms out over the euro/Asian region. However at the moment, despite the claims that the MJO will kick in with some wave breaking, there is no sign of that yet, and I have now pretty much given up on any consistent MJO forcing this winter. So with a weak PV just moving with the flow, but primed for destruction, we await a trop led 1 or 2 wave push.Looking at the D16 GFS op there is minimal hints of either in the short term: The control and GEFS are all different so that D16 chart is unlikely to be repeated in the medium term. In the next week looks like the SE should have max temps above 10c every day so a pleasant change for us 5 am risers as lows will be very mild January has seen a cold spell (SE especially) temp wise though for snow lovers again disappointing. CET should be close to average so even with that rare UK cold spell it is hard to get a significantly cold month!

Whilst the outlook remains the same, it is to be noted that the extended eps trend is along the lines of the latter frames of the op whereby those lower heights drop further south into France and Iberia. That will always give rise to runners in the base of the trough which at this time of year, could deliver some of the white stuff to the south of the uk whilst the northern half sit under cooler uppers anyway and cool zonality always carries potential. let's see if tomorrow's suites follow suit.

The Met Office website is a mess all round, to be honest.