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if I had a pound for every FI potential winter outbreak I would be a rich man. I see nothing to get any excitement about, all pretty bog standard by the looks of things- always remember the rule of thumb, if it can go wrong it will and stellar charts always downgrade come the day.
Originally Posted by: JACKO4EVER
That's no way to live!
However I agree with Maunder on this one. Caution is always wise of course, but the month ahead looks like the most promising spell for cold and snow so far this winter.
Pretty solid agreement from the 12z GEFS for widespread sleet and snow next Tuesday as a trough disrupts bang over the UK. This is close to the holy grail for widespread snow, FWIW, as it'd involve the occluding front "riding up" on top of existing low-level cold air, all the while with really cold upper air catching up, isolating the (still not exactly mild) air in the middle! Get the timings right and you'd be looking at a real dump of snow.'Course, this far out it's bound to change... I wouldn't be at all surprised if, for example, the trough ended up disrupting further west as the block to the east is underestimated. We've seen that time and time again in the past with models being if anything too progressive - not every time, but often enough to be wary. The other thing is how much milder air gets sucked into the warm sector; the operational GFS seems to be at the top end, though, and even that brings a snow-rain-snow event pretty much countrywide. MetO would undoubtedly keep it as snow throughout, a vanishingly rare event in recent years. For once, I'm really interested in the models. It's fascinating watching them trying to resolve the trough disruption and ensuing attempt to bring back the Atlantic.
Best and coldest spell of the winter coming mid-month with the Strat warming and split vortex - showing up already in the GFS charts. Still FI for now - but watch events unfold from 12th Feb onwards.
Originally Posted by: Maunder Minimum
What strat warning?
Originally Posted by: doctormog
There appears to be one forecast on the latest GFS run, but I don't really follow the ins and outs of the SSW witchcraft...
...and as perhaps would be expected given the means, the op GFS was indeed on the warm side with the warm sector around 144 - there are 3 members which bring a much warmer sector, while the GFS maxes out at -4 for London. The mean at that time is -7 and there's one lovely run which keeps it at -12 throughout that period! Still much to be decided, but bearing in mind this time yesterday the mean for the time in question was -4 (op -2) it's quite an improvement. It's also a reminder that the entire suite can change "just like that" at relatively close range if it's picked up on a different signal. A 3C change in the mean at 168>144 is a fair old whack, after all...
Originally Posted by: Rob K
The GFS quite often shows output like that in the long range but it rarely comes to fruition. From what I have seen of the stratospheric outlook there is no SSW in the offing.
That aside, chilly and messy seems to be the order of the day. Tuesday is of some interest but it’s also almost a week away so I might believe the snowy charts if they are still there next Monday
6z gives the following Snow Row 'chart':
1) Inverness - 311
2) Newcastle - 245
3) Norwich - 203
4) Glasgow - 199
5) Liverpool - 187
6) Birmingham - 171
7) Belfast - 170
8) Edinburgh - 162
9) London - 150
10) Aberdeen - 141
11) Cardiff - 130
They're pretty astonishing numbers.
Originally Posted by: Saint Snow
Astonishing doesn’t begin to describe it. Aberdeen is supposed to be Britain’s snowiest city and there it is languishing down the list barely ahead of Cardiff.
The summer equivalent would be London second from bottom on a heatwave list ahead of only Lerwick. That’s how big a joke this is
The strat warming being forecast by GFS and JMA starting around the 10th Feb.
https://twitter.com/DrAHButler/status/958741410567438336/photo/1
Just for fun!
Here's what ensembles look like before a cold spell sets in:
Today's chart:
And the ECM sides with MetO tonight!
120 - says it all, I think.
If you are to go by the ensemble mean then that shows zonal wind reversal (10 hPa at 60°N) at around the 14th or 15th of February. I tend to look at the ECM as experience suggests it is more reliable at that range and it does not show any SSW, hence my question. http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/fluxes.gif
Originally Posted by: Retron
As good as you could wish for these past few years with an upper trough over sub -10 uppers. A snowy chart for the SE and a very rare things these days.
12z GEFS snowrow is interesting to say the least.
It looks much more dramatic on their colour scheme than it does on Wetterzentrale's. :)
ECm 12z at 144 also looks very cold.
Very impressive chart with uppers of -12 (and lower)
Could be a classic squeeze and stalling front producing (plenty of) snow, but where exactly will it be, as could be quite a narrow band
Brian, is it possible to tweak the ECM thickness charts so that they draw more labels on the thickness lines? Some charts seem to be missing them altogether, eg:
Yes that's on my to do list.
Well ECM looks the best of some poor output tonight.
12z Arpege showing the possibility of snow even in the south this Saturday.
Originally Posted by: Surrey John
No. You are totally misreading the synoptics. The cold air is in place over England but warmer air is aloft from the Atlantic. This mixes out the cold layers and a weakening band of PPN sinks SE.
Originally Posted by: Shropshire
Have you had a bad day at work Ian? Normally I rate your commentary highly for its realism. Today I think you're being unduly pessimistic.
Don't really understand how anyone can view what we are seeing as poor.
OK, the easterly looks to be off the table for the time being anyway, but I see no indication in the models of a Bartlett/Euroslug type set-up developing.