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phil nw.

Model Output Discussions 06z 04/11/16

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Well GFS has just shown us how you can go two weeks with a mean less than 1.5*C without having to import particularly cold air from the continent or Arctic - it's a beaut for homegrown cold under inversion conditions.

Using the raw data (flawed I know!), for a large part of inland E&W the average minimum for the period is near -1*C and the max a little below 4*C, and this is with the known poor resolution of locally much lower temperatures under inversions such as I chatted with Knocker about earlier. Freezing fog could produce daytime highs a number of degrees lower at times too.

Sure, we may well end up with a more active weather setup instead (whichever way the winds are blowing...), but I thought it was worth taking a moment to appreciate what can happen under a very resilient UK-centred High in the month with the longest nights :)

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Models showing why not be too quick re writing the month ahead off when there are so many variables that can assist below normal temps. We are in new waters.  Look at that ECM change was it Fri or Sat 00z.  

Incredible low temps coming tonight....off a quite benign set up.  -8 anyone??

 

BFTP

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If high pressure does dominate, lets just hope its a clear high rather than a cloudy one as the cold frosty nights and sunny/foggy days are a lot more interesting than cold grey days with no frost. I think the biggest uncertainty will be the cloud cover, hopefully after a cloudier few days from Wednesday onwards we should see clearer conditions come in from the North as the Northerly flow just misses us but it should bring cooler/clearer air in and with the high forecast to be right on top of the UK hopefully we will see the sunny days and frosty nights.

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24 minutes ago, MattHugo said:

:p

Good to see the UKMO still agree with Tony and I regarding the winter period...

http://www.metoffice.gov.uk/binaries/content/assets/mohippo/pdf/public-sector/forecast-temp-djf-v1.pdf

Matt.

 

Looks very promising for your forecast (certainly the first month anyway), still disappointing that they seem confident of colder than average conditions being by way of high over us though than to the north

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Has to be said, a rather poor meto update today for the first fornight of Dec, screams a sinking high and jet running over the top.Nothing resembling Gfs 6z anyway...

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11 minutes ago, Geordiesnow said:

If high pressure does dominate, lets just hope its a clear high rather than a cloudy one as the cold frosty nights and sunny/foggy days are a lot more interesting than cold grey days with no frost. I think the biggest uncertainty will be the cloud cover, hopefully after a cloudier few days from Wednesday onwards we should see clearer conditions come in from the North as the Northerly flow just misses us but it should bring cooler/clearer air in and with the high forecast to be right on top of the UK hopefully we will see the sunny days and frosty nights.

absolutely agree with this. Cold, frosty at night and clear by day and feeling very seasonal - fingers crossed we dodge the cloud. To be honest I think it's a great start to winter - too often down here (in the subtropical south) genuine snow chances elsewhere translate into raw, cloudy, cold rain for us. Personally some proper frosty weather to welcome the start of the festive season and beginning of winter is actually preferable in many respects.

And as IDO earlier (and numerous others) points out, who knows where it leads after that? Surely our time has come for the high to migrate somewhere favourable for a snowy outbreak for a change?

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6 minutes ago, Certain kind of fool said:

And as IDO earlier (and numerous others) points out, who knows where it leads after that? Surely our time has come for the high to migrate somewhere favourable for a snowy outbreak for a change?

That might be the case, but there is nothing in the model output presently which points to this. The PV might be disturbed but the blocking is not where we want it to be other than continue to with our mid latitude high. At least if things were more mobile we might get a toppler or two bringing snow.

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20 minutes ago, mountain shadow said:

That might be the case, but there is nothing in the model output presently which points to this. The PV might be disturbed but the blocking is not where we want it to be other than continue to with our mid latitude high. At least if things were more mobile we might get a toppler or two bringing snow.

None of us know where this high will eventually end up but going back to 63 the weather of early / mid December gave us a high which moved south from Arctic regions into the baltic, stayed there for a while and then moved westwards introducing very cold dry frosty weather before collapsing as a new centre moved slowly North East to Iceland introducing bitter cold and a white Christmas to Glasgow.

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26 minutes ago, SteveB said:

In a standard Winter when the Vortex is resident in it's normal place & normal Strength, then yes a sinking high would be the form horse.

But the vortex is weak & not in it's usual place, this leaves options on the table, hence why Meto update is a little cautious.

All to play for still, and the chase for snow is still on, you could never have said that at any point last Winter....

Plenty of nice chilly night to come too, with some hard frosts.

I was thinking the same thing

gfsnh-0-336.png?6gfsnh-12-336.png?6

That aleutian high anomaly seems to be growing larger on each run, could we not see a link up between these two highs with a bit of tweaking?

 

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1 hour ago, knocker said:

Well I dunno about deep cold

gefs_t2ma_5d_eur_61.png

But this rather ignores the almighty split on the ensembles after around D8. Either very mild or bitterly cold!

graphe6_1000_269_88___.gif

Edited by Man With Beard

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1 hour ago, Summer Sun said:

06z Op colder than the mean for the 850's that's not to say it won't be cold at the surface may be higher single figures instead of low single figures

gefsens850London0.png

Control and mean very close from the 6th to 13th

Obviously depends on how low they go overnight , tonight JH is talking -7 or -8 in rural areas tomorrow could be a 4c or 5c day ......................time will tell of course

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Cold frosty and dry for my location is certainly better than an unsettled  toppler type scenario.

That always transpires into a cold wet (just above marginal) slush fest.

Get the cold locked in and hope for upgrades.

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26 minutes ago, Rollo said:

None of us know where this high will eventually end up but going back to 63 the weather of early / mid December gave us a high which moved south from Arctic regions into the baltic, stayed there for a while and then moved westwards introducing very cold dry frosty weather before collapsing as a new centre moved slowly North East to Iceland introducing bitter cold and a white Christmas to Glasgow.

Is there a model showing this scenario?

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12 minutes ago, snowbob said:

Cold frosty and dry for my location is certainly better than an unsettled  toppler type scenario.

That always transpires into a cold wet (just above marginal) slush fest.

Get the cold locked in and hope for upgrades.

Absolutely, topplers are no fun at all, an hour of snow if lucky turning to slush then rain, no thanks. Weather like today (sunny and cool) is lovely in winter. 

All to play for imho; the PV is weak/disorganised and blocking is featured strongly. Nothing like last year or other recent winters. And it's not even December.

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2 minutes ago, stainesbloke said:

Absolutely, topplers are no fun at all, an hour of snow if lucky turning to slush then rain, no thanks. Weather like today (sunny and cool) is lovely in winter. 

All to play for imho; the PV is weak/disorganised and blocking is featured strongly. Nothing like last year or other recent winters. And it's not even December.

Still think people are judging December last year as the story of the whole of last winter because one could argue at the moment January 2016 had more potential than at the moment because we had higher latitude blocking and the PV over the Arctic was more or less destroyed hence the warm Arctic winter up there last winter and beieve it or not, there was some cold with a little bit of snow but in general it never fell favourably for the UK,

At the moment, it seems like a slow burner, I think aslong you got the attempted ridges and the cold to the East then theres always a chance, last thing we want too see is the PV to ramp up over Greenland, strong jet stream which in turn will eventually pull that cold air away from Scandi and we have to start all over again basically, no real sign of that at the moment but its always a possibility.

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Interestingly if you compare the graph from the November meto update to this update the inflection point has moved closer to colder.

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10 minutes ago, mountain shadow said:

Is there a model showing this scenario?

If remember rightly didn't some of best winter weather come from high pressure over or near to U.K. :D

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3 minutes ago, Geordiesnow said:

Still think people are judging December last year as the story of the whole of last winter because one could argue at the moment January 2016 had more potential than at the moment because we had higher latitude blocking and the PV over the Arctic was more or less destroyed hence the warm Arctic winter up there last winter and beieve it or not, there was some cold with a little bit of snow but in general it never fell favourably for the UK,

At the moment, it seems like a slow burner, I think aslong you got the attempted ridges and the cold to the East then theres always a chance, last thing we want too see is the PV to ramp up over Greenland, strong jet stream which in turn will eventually pull that cold air away from Scandi and we have to start all over again basically, no real sign of that at the moment but its always a possibility.

 Last year I saw snow falling twice; once in November. But then we all know what happened in Dec. My point is that its the end of Nov and this Dec looks very different to last year and some other recent winters where we were blasted by endless Atlantic storms. So, we have 3 winter months to get cold conditions, of course mid Dec onwards could throw anything at us but we're not in a bad position at all to start the season. It's very nice just to see high pressure modelled as this in itself has been severely lacking in recent winters!

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