Model Output Discussion - 5th December - 11th December

[casparjack]

Big difference at just +144 with the ensemble means of GFS/ECM.

GFS

ECM

Though even GFS turns more zonal later. My bet is on ECM/UKMO unsettled zonal outlook.

GEM looking very unsettled and zonal too

I've taken out the charts to avoid using loads of additional space, but considering they are the 'ensemble means', they all look remarkably similar to me, apart from subtle differences in the position of the high (none of them favouring real cold for the UK) - I think that gives a very strong and perhaps largely unwelcome signal.

[Frosty.]

It's a shame that nobody is interested in the polar low which is likely to hit shetland and orkney, maybe the northeast of scotland..they are rare but I suppose it's because it won't affect anywhere else but for those interested, it could produce several inches of snow and blowing snow as winds become gale to severe gale force in that northeastern corner of the BI.

[chionomaniac]

It's a shame that nobody is interested in the polar low which is likely to hit shetland and orkney, maybe the northeast of scotland..they are rare but I suppose it's because it won't affect anywhere else but for those interested, it could produce several inches of snow and blowing snow as winds become gale to severe gale force in that northeastern corner of the BI.

Is there a sat image of this pl?

[nick sussex]

In terms of the upstream pattern and the eastern USA, NOAA do prefer the Euros and GEM, they discounted the GFS 00hrs and GEFS ensemble means.

The ECM/UKMO at 96hrs do bring some cold air quite far south, we'll have to see whether we can squeeze a touch more amplification upstream.

We have had alot of chopping and changing over the last few days, I'm not sure whether we're going to see many big changes now in the overall pattern, but thats probably asking for trouble given the last week!

[Frosty.]

It's a shame that nobody is interested in the polar low which is likely to hit shetland and orkney, maybe the northeast of scotland..they are rare but I suppose it's because it won't affect anywhere else but for those interested, it could produce several inches of snow and blowing snow as winds become gale to severe gale force in that northeastern corner of the BI.

It's a shame that nobody is interested in the polar low which is likely to hit shetland and orkney, maybe the northeast of scotland..they are rare but I suppose it's because it won't affect anywhere else but for those interested, it could produce several inches of snow and blowing snow as winds become gale to severe gale force in that northeastern corner of the BI.

Is there a sat image of this pl?

I don't know, I was just looking at the gfs 6z and it looks like an example of a small but potent polar low but I could be wrong although if it does what it says on the tin and delivers heavy snow and gales, it will be as good as a polar low. Edited December 5, 2011 by Polar_ Low

[johnholmes]

http://www.yr.no/satellitt/europa_animasjon.html

is a nice movie of he past 24 hours.

I'm not sure it is a polar low but Dave Wheeler on Orkney or rather Fair Isle in his weather forecast seems to think it is. Whatever; it is likely to give a spell of snow for the N Isles and possibly the far north of Scotland. Quite a potent feature.

[Polar Maritime]

Has anyone got an idea what the near-surface wind speeds are regarding the suspect Polar Low ?

17 m/s (or 38mph) or more, Then it's a Polar Low.

Edited December 5, 2011 by snowrob

[NorthernRab]

Is the polar low that feature that appears near the Northern Isles at around midnight?

[Tom Montalbano]

Yes JH, lovely movie there.

You can clearly see the feature forming NNW of the N.Isles and this is forecast to be just N.E of the Shetlands by 6 a.m tomorrow morning, as shown on the Fax chart for t24.

http://nwstatic.co.uk/fax/PPVE89.png

Winds will increase on the S.W of this small low after midnight and conditions could become quite nasty over the extreme N./N.E of Scotland and the N.Isles, with a spell of snow, with drifting in the strong winds. GFS 850 chart for 6 a.m tomorrow:

http://hw.nwstatic.co.uk/gfsimages/gfs.20111205/12/18/h850t850eu.png

Regards,

Tom.

[Matty M]

12z GFS is very different to 6z

Really big differences at short timeframes.

[karyo]

12z GFS is very different to 6z

Really big differences at short timeframes.

It looks similar to the 0z ECM.

Karyo

[tinybill]

this should wet peoples lips for wednesday

[chionomaniac]

http://www.yr.no/sat..._animasjon.html

is a nice movie of he past 24 hours.

I'm not sure it is a polar low but Dave Wheeler on Orkney or rather Fair Isle in his weather forecast seems to think it is. Whatever; it is likely to give a spell of snow for the N Isles and possibly the far north of Scotland. Quite a potent feature.

Cheers John

this should wet peoples lips for wednesday

I should imagine it will soak them all over tb.

It seems that the door to cold is getting shut fairly soon after opening as the timeframe for this weekend gets closer. It would be no surprise to see the -5ºC 850 not even reach southern counties by the end of the week - not that I ever thought it would.

[Tim Bland]

this should wet peoples lips for wednesday

If you live on the top of the pennines or in the Cairngorms maybe! For the rest it will be rain maybe sleet in the north

Edited December 5, 2011 by Tim Bland

[Pennine Ten Foot Drifts]

this should wet peoples lips for wednesday

The emphasis being on the 'wet' I assume (at least for anyone not up a mountain)

[Cecil Hogmanay Melchett]

GFS 12z is not pleasant for coldies with the PV set up to the North west and HP remaining stubborn over europe.

Still,had some wet snow overnight and this morning leading to a dusting on the wheelie bin.

[Dale Leigh_6487]

according to the met office update the north will be cold for sometime with snow down to low levels at times with frost and ice risk as well as milder blips, the south staying in the mild category. i know the southern people will be less fortunate but i think the cold will come here too. patience is the word. models not to inspiring for the south i see.

[shedhead]

Cheers John

I should imagine it will soak them all over tb.

It seems that the door to cold is getting shut fairly soon after opening as the timeframe for this weekend gets closer. It would be no surprise to see the -5ºC 850 not even reach southern counties by the end of the week - not that I ever thought it would.

Well they do say familiarity breeds contempt, but there is definately a clear familiarity between what was previously progged for Friday, what is now being shown what will no doubt ultimately happen. If ever a weather senario deserves the 'seen it, done it, got the t-shirt it surely must be these Pm incursions. Rapidly developing into another all to familiar 'blink and you'll miss it' job.

[chionomaniac]

Well they do say familiarity breeds contempt, but there is definately a clear familiarity between what was previously progged for Friday, what is now being shown what will no doubt ultimately happen. If ever a weather senario deserves the 'seen it, done it, got the t-shirt it surely must be these Pm incursions. Rapidly developing into another all to familiar 'blink and you'll miss it' job.

Yes and the door to cold is closed on the UKMO.

I wonder what the ECM has in store next.

[Optimus Prime]

North westerly winds are never productive for the majority of England with temperatures often being near normal. This time however it's been pretty good across Scotland with cold and some snow.

The lack of heights to the north and north east should be enough evidence to suggest the longer term pattern will remain mobile and at times mild.

[Summer Sun]

this should wet peoples lips for wednesday

Yes it will if you love lot's of rain those hoping for snow will not be happy unless they are in places like The Cairngorms

Early hours of Friday has some pontential

Edited December 5, 2011 by Gavin D

[Frosty.]

Well they do say familiarity breeds contempt, but there is definately a clear familiarity between what was previously progged for Friday, what is now being shown what will no doubt ultimately happen. If ever a weather senario deserves the 'seen it, done it, got the t-shirt it surely must be these Pm incursions. Rapidly developing into another all to familiar 'blink and you'll miss it' job.

Do Pm incursions ever amount to anything in ilchester? it still looks like a second cold swipe for the northeast of the uk after a less cold interlude on thursday morning, friday looks bitterly cold with snow showers in the far north of the uk.

[SnowObsessor90]

Seems we've gone in just a few weeks from euro/bartlet mundane boredom to zonal/Atlantic driven boredom.

So not much progress at all really towards proper cold conditions in spite of the odd toppler we're still in the process of.

Edited December 5, 2011 by Anonymous21

[weathe20]

bor fest. Friday into Saturdays cold seems to last only hours now. Then zonal all the way. This IS the theme.

[clark3r]

rubbish for the south!!!!!!!!!!!!!!!!!!!!1