Cheshire Freeze

If there is an exceptionally strong signal it will run with it...it did brilliantly during the March-April 2013 spell. Had it nailed weeks before (and remained steady right up until the event).

I'm actually slightly concerned by the CFS v2 daily runs at the moment. For the past two days worth of runs, the N blocking signature has completely crumbled for Dec and Jan, replaced with something utterly more average. You can't even claim run to run variation on this because up until a couple of days ago it was resolute with the blocking signature for December. I'd expect to see the blocking ebb away from the means on the NOAA site over the next couple of days given what I've seen. I'm not saying it's the death knell for December cold but it's something to be wary of at least.

Yep, seems to be really having a number done on it this year; with the potential for further weakening courtesy of a warming.

It's almost as if it's trying to initiate a block which stretches all the way from the east of Canada right across to Scandi. Can't say I've seen the likes of this thrown out before even in deep FI. Really is bizarre stuff

Bizarre chart...truly bizarre. Looks like it's heading for the mother of all west based -NAOs Strat looks to be in a bit of bother at the end of the run too

Pub run turning into a beauty...poles apart from the ECM

No those 27 members were cyclonic at that specific point in time (end of November) but there's nothing to say that another half of those didn't go on to be blocked a few days later.

I'm really struggling to remember snow at all last winter. Think there was one (very small) wet fall at some point but hardly worthy of being called a snowfall. It really was dire.

Nope!

Looks suspect as early as day 5 to me blue.

I think the GEM is about to hit on a new pattern in upcoming runs...its 12z run looks slightly implausible to me out towards days 9 &10 *hint* attempted Icelandic blocking along with E European blocking divided by the skinniest trough you'll ever see...

As I said earlier, Will, The Jan-Mar anomalies for pressure look to me to be signalling the potential for a snow maker of a battleground between colder continental air and Atlantic LP systems. Just has that look.

It's no classic Cheshire gap scenario. Winds are too westerly so the only areas which will get the shower stream is Mid and north Cheshire northwards; Greater Manchester and the like. Reminds me of the '09 and '10 spells when the same thing happened. Winds need to be direct NW'ly for a true Cheshire gap streamer to set up which would push the showers right down into Staffs and west Midlands. You can see there is nothing remotely NW'ly about surface winds and steering flow would most likely be westerly.

I don't bother looking at the percentage terciles...IMO they're about as much use as a chocolate fireguard given vagaries which show over and over again with temperature plotting and deviation from long term means in terms of anomalies presented. The only one I'd look at is the precipitation output. I'm personally much more interested in the MSLP anomalies...I can extrapolate probable surface conditions from that!

That GLOSEA run does not suggest a front loaded winter though. The potential for cold actually intensifies in the Jan-Mar time frame with the jet diving down through the UK and a strong block to the E... Looks like battleground UK to me on the above chart...the one that springs to mind is Feb 1996

Personally, that GLOSEA update is not for me...I'm looking at that thinking there would be frequent interludes of S'ly winds as low pressure stalls to the W and SW rather than running underneath the block which, may at times, be further S than Scandi. If anything, that run departs from the Metoffice narrative so far as it looks as if it actually gets colder further into winter/early spring.

Atlantic blocked by day 9 on the 0z GFS Hard to see the Atlantic powering up after this point on this particular run. Let's see where the blocking takes up residence towards the end of the run and whether we get to tap in to any cold uppers... We do indeed...bingo The GFS 0z then locks us into the cold up until the end of the run, with a slight readjustment and an even colder flow poised to head down from the N All in all, stunning output there in FI.

Rasping northerly towards the turn of the month on the 18z That would be some curtain raiser to winter 2016/17

Carbon copy run from CFS today for December Some tasty uppers too coming in 4-6C below LTA

Current CFS run

Beginning of the end of this more mobile spell at day 10...vortex should smash itself to pieces henceforth given the N hemispheric pattern Be interesting to see what it throws out latter FI

Oh, here we go..

Bit of a bonkers run to be honest...just look at all that WAA heading due N straight up through W Russia...would think that would have consequences through deep FI

18z very good IMO in context of recent runs...difference upstream from 12z is clear to see

Looking at the GFS output at face value I'd suggest that it would go on to produce a SSW in the long run but I'm not clued up on that side of proceedings...far more learned members on here.