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Hi all, I'm not seeing anything wintry as such from the latest models, par for the course really!...still, at least we have brexit to look forward to..or not as the case may be!..not sure I will be posting much in the weeks ahead but thanks to those who messaged me during my long absence..much appreciated.

For goodness sake !!!!!!! exeter are speaking about events beginning almost three weeks away maybe we should limit this thread to only referencing the next two weeks ..... infact, as its model discussion, unless you are posting about the long range models, then maybe limit the chat to 16 days as per the modelling

Who cares? They flip flop up and down like a lady of the night’s knickers! Growing momentum of the LP around 8th Dec being the trigger period to bring in the real cold set up. Very happy with models thus far BFTP

Cohen speaks of an event next weekend and you reference events between 2 and 4 weeks .......... incidentally, Exeter speak of settled and cold I wouldn’t normally comment but some less experienced members may be confused

“It’ll be zonal for weeks” ”No sign of any cold” ”I thought this was the hunt for cold thread not the “wish cold into existence thread” Comments like that almost continuously for over a week, have all those people gone back into hibernation now? GFS 12z showing what could happen if everything falls into place, GFS also showing a solution well supported within the EPS. Can’t wait to see the GFS(P) and the GEFS

GFS only out to T180 and you can see already it is going to be a stonker: The width of the high pushing north and the strength of the low driving the warm air advection north are key here. Wish my iPad would stop changing stonker to stinker, really changes the emphasis of my post!

All the warning signs are there (and have been for a number of weeks) that we're about to enter the freezer good and proper in a few weeks time. We look to be building the foundations of a potentially severe spell of winter weather...possibly at the coldest part of the winter. The strat vortex looks toast in the longer term too. All in my humble opinion of course.

I can't stress how important the time of year is here. By day 10, even under not an especially strong/cold E'ly flow, the UK will slowly but surely begin to freeze over as there is an overall heat loss. Good news for those wanting a festive run up to Christmas! Even if there isn't much snow about. It's why I much prefer winter to start earlier rather than later...

UKMO 144 looking pretty solid ! The ridge of weak ridge High pressure over Iceland helping steer that low SE

EC is lovely this evening.. Big scandy high and cold and dry for the UK.. Id take that run right now.

No wonder you have a sore paw !

T218 nice 1048mb high. I've printed this one off And placed it on my bedroom wall next to Rachel Riley.

Regardless of the next couple of weeks the long term pattern going into the winter is definitely positive!

FV3 looking great at 174 with deeper cold in Europe-

Excellent FV3 sees the best case scenario for the block it also runs out a full retrograde to Iceland...

There would be ice days for a few, even at this point with a 1040mb high and being mid December. Hard overnight frosts would be likely too.

For those newish looking in- subtle differences play out a big change- At around 156 we want the secondary ridge more amplified than the first ridge in the atlantic which steers the low more SE Here the 06z V 00z is much better

Morning all, remember in yesterdays post , I mentioned we now have to look for some consistency in the models and compared with the previous 24 hours projections. Looking at this mornings , it is there . The GEFS control at 192t picture below shows this. Also backed up by ECM . So I would expect strong ridging to develop to the NE by day 9 (216t). Obviously there will be variations during the interim operational runs but the trend to a colder outlook continues for most in Europe during the second week of December. Shown below is chart of the day at 240t produced by the Canadian Met NWP model ( now that would be something )!

You know the cold potential has come back when there are over +150 members here!

And we finish like this!!! Invasion of the PV from the north. What a wild run that was. No doubt it'll be totally different on the 18z but tremendous fun all the same.

Somewhere inbetween ..................

Brilliant when a positive means a negative

GFS stop it lol. Reminds me of December 19...?

seems that the obvious trend is that the ridge won’t get the traction to sustain far enough north initially - what happens in the Atlantic subsequently dictates if we drive another bout of WAA to form a proper scandi ridge currently looking messy but pretty confident that a nw European high is pretty solid ...... likely to be cold one but how cold dictated by whether we are generally cloudy or clear there remain many routes on the table re how this ridge sets up through week 2 (does it settle scandi?) and the puzzle solved eventually by how much goes into the northern arm and how low heights over se Europe are able to drift west. the Atlantic jet in the extended continues to look pretty weak and the mean tpv still centred ne Siberia end week 2 on the eps. Glad Daniel got those cushions for my fence ..........

ENS give very good support to winds N backing to NE

I'd take this from ECM at the end of the run! This Scandi block looks very likely now, it's going to become a question of what it means for us now....

Looks much better than earlier. Ridge going north of the U.K. could end up over scandi on nxt frame ?

This gfs op run showing a closer tie to the upper strat modelling that the op and gefs have been showing recently ....

GFS is my idea of heaven lol..

The chart below from is the mean ECM run for 192t and kind of in sync with the GEFS control run for the same time, which is a good thing. So this time tomorrow we need to look at the 168T charts to get a comparison. What we are looking for is consistency in the outputs. If get the same development by 144t , we increase the chances of a sustained forecast to colder weather. Hang on to your hats but as I mentioned, so far , so good. Do not be put of by the variability of the various op runs as they can easily switch outcomes in the period 168t -240t . C

A step in the wrong direction this morning from the 00z GFS and EC ops, difference between these and the better GEM is that they are more progressive with shifting the trough to our east eastward- which allows the jet to buckle further east. We need it buckling further west to build the ridge N/ NE, otherwise we miss out on any deep cold and any ridge slides SE over UK as another jet surge upstream works through, thanks to steep upper temp gradient on base of the trop PV over Greenland. However, the 00z EPS and GEFS mean at day 10 still suggests broadly a strong ridge over UK toward Norway, with Euro trough still close enough and uptream troughing into N Atlantic far enough away. So we may see some better GFS and EC ops in coming runs, given building blocks for the ridge to develop still far enough away in timescale to accommodate changes.

Ec op better with the Atlantic dropping some troughing to our west - previous run pushed the Azores ne and over ran the ridge it merely illustrates how uncertain the whole nature of the amplification is - best to plump for the blocking over us - covers most bases !

One aspect that hasn't been discussed from the GFS and FV3 12z output, is the eventual position of the trop PV, if it ends up as illustrated by either models at T384 then I'm calling game on! for the winter!

Not being funny but i have to say that at least this thread has the correct theme - searching for snow because most of the people on it are of the snowflake generation.

This would be a great position to be in, fingers crossed.

Big shift in the mean compared to the 06z @ D8, looks like we could be in business. It would appear that some of the milder ENS members have turned cold after all!

Two words, 'yes please'! What a bonkers chart. If we could get to here..... well, the mind boggles!!! And look at the cold pool to the north! (and yes I know this is at 300hrs)

GEM out to T240, quick tonight, and it is a massive block.

Afternoon All - some statistical November analysis on the Arctic Oscillation- Nov 18 has now finished & the im just waiting on the final number which is will be around -1 AO In terms of the Winter Forecast the data is very pleasing ( especially if we do break -1 AO ) The table below shows all months from 1950 AO - There are 12 Sub -1 Novs the least The 12 -1 Novembers were 1952, 1955, 1957, 1959, 1962, 1965, 1968, 1980, 1985, 1998, 2000, 2002 In terms of the following winters we have a 30/36 hit rate for -AO Months These winter height anomalies are below A good match for the forecast underpinned by the December theme with lots of Euro troughing Incidentally the best 3 Nino matches were 1952/1959/1980 Heres a final thought- If we take the daily AO data in terms of Depth of AO for final part of the month & compare with November 18 ( Sub -3.5 values we get ) Nov 62 , Nov 65, Nov 68, Nov 85, Nov 2010... Thanks...

I concur with those who foresee a multi-ridge-build route to a ‘proper’ cold feed. Theres enough broad-scale support for ridging to shift the Atlantic troughs away from the UK by day 7 or 8, but further amplification is then required to take that ridge further north. This is where severe strat vortex disruption coupled with a fast propagating MJO can come in very handy.

Given that we have (for now) a consistent signal to displace the stratospheric vortex over Siberia in around 15 days i can actually see the logic in high pressure tending to sink over/west of us after a brief easterly attempt such that the tropospheric vortex can drop a Scandi trough. We may have to wait a few extra days but i can definitely see the support for northerly over easterly.

They flip flop all the time,no consistency at all,which maybe a good thing if you think about it.Roll on the ECM

In this country, cold spells are generally brief ........ getting a spell rather than a snap is the trick !

I see the charts continue to push the cold our way. Still not a done deal but something's brewing I said yesterday there is strong similarity with 2009 2010. If the ECM onboard later and I know the gem is I'd get the shovels at the ready. Incredible displacement of the vortex to our side nearly the entire lobe of vortex incredible. And I'm still punting on a Canadian stratosphere warming event to.

This could be an epic FI, retrogression and another blast of WAA heading up the West of Greenland to help that - could be one massive Block here.

It’ll be gone by morning only to be back again by tomorrow evening.. seems to be a trend.

loving the gfs parallel again,with the deep purples appearing at the end heading South,maybe we might see the black hole appearing when 850 hpa air is 474

If you haven’t viewed the models yet: I’d suggest that you start with the GEM and skip the rest...just imagine they are the same as yesterday, that way you will have a good morning!

00z GEM is a very good outcome. If I'm being Craig Revel Horwood and looking for something to critique I'd want the high to end up further north so more of the UK can get in on the action but still very decent.