Model Output Discussion - 5th December - 11th December

[NorthernRab]

yes

In FI

That's more Fantasy Planet than Fantasy Island it's so far away!

[rich1]

Doesnt look all that different from the chart shown for the 15th a week ago as I said

curious really...

out until the end of the reliable, the further north you go, the wintrier the picture looks

[Snowmad79]

yes

In FI

Deep deep deep FI and there's more chance of Ian himself dropping down my chimney christmas eve than there is that euro high developing.

[Cheshire Freeze]

Deep deep deep FI and there's more chance of Ian himself dropping down my chimney christmas eve than there is that euro high developing.

God, that'd give the kids nightmares.

Is this your image of a 'modern Christmas'? I'm sure if he had his chance he'd be delivering presents of bartletts to every household in the land

Edited December 7, 2011 by CreweCold

[ChartViewer]

Deep deep deep FI and there's more chance of Ian himself dropping down my chimney christmas eve than there is that euro high developing.

Why if the stratosphere stays very cold , jet stays north, that scenario suggests height rises to our South with very low heights to our North?

Isnt that far fetched seeing the pattern has continued for last 4 weeks with Euro high, cold strat, low heights to North, jet north....upstream pattern not good for change.

Edited December 7, 2011 by ChartViewer

[PMPhotography]

Is there no chance of snow in the east as the low passes through? GFS briefly leaves us with a N/NNW flow on Friday. Uppers look cold enough at -8 with a dam of 518. Surely the strength of the wind would produce convective showers into some extreme eastern locations for a time. Of course this set up would increase the risk of coastal flooding too.

Can't see it in any forecasts so I'm wondering what I'm missing!

Edited December 7, 2011 by PMPhotography

[Snowstorm1]

Why if the stratosphere stays very cold , jet stays north, that scenario suggests height rises to our South with very low heights to our North?

Isnt that far fetched seeing the pattern has continued for last 4 weeks with Euro high, cold strat, low heights to North, jet north....upstream pattern not good for change.

The thing is the jet is moving south

[ChartViewer]

The thing is the jet is moving south

No it isnt in this pic

[Summer Sun]

Friday and Saturday looks rather snowy for the far north

http://hw.nwstatic.co.uk/gfsimages/gfs.20111207/12/45/prectypeuktopo.png

http://hw.nwstatic.co.uk/gfsimages/gfs.20111207/12/51/prectypeuktopo.png

http://hw.nwstatic.co.uk/gfsimages/gfs.20111207/12/57/prectypeuktopo.png

http://hw.nwstatic.co.uk/gfsimages/gfs.20111207/12/66/prectypeuktopo.png

http://hw.nwstatic.co.uk/gfsimages/gfs.20111207/12/72/prectypeuktopo.png

[swilliam]

No it isnt in this pic

We have just established that using a chart (the same chart in fact) at T384 is hardly illustrative of what might happen in the future

[Aceman]

No it isnt in this pic

Not sure something 3 weeks away can be taken very seriously

[Glacier Point]

12z GFS ensemble mean has a -380m height anomaly for that intense upper low programmed t144 thru t168; potential for a large windfield with widespread disruption on that one.

Interesting as it also throws up a +200m height anomaly into the Arctic which squeezes the polar vortex towards the Pacific side before lifting out and weakening. Hard to imagine that we won't get some energy bleed south-east into the Balkans but possibly a bit too much inertia up north for this to have an impact this time round though.

[Snowmad79]

Why if the stratosphere stays very cold , jet stays north, that scenario suggests height rises to our South with very low heights to our North?

Isnt that far fetched seeing the pattern has continued for last 4 weeks with Euro high, cold strat, low heights to North, jet north....upstream pattern not good for change.

Wasnt the stratosphere similar back in 2007 ? was looking at the archives again for Nov - Dec 2007 and although theres similarities the Jet is still strangely tracking more southerly. You'd have expected the Jetstream to have wound back up north by now with the strengthening westerlies around the pole? I would.

@ Crewcold .. haha nevermind the kids, even I would have nightmares if that happened!.

[ChartViewer]

We have just established that using a chart (the same chart in fact) at T384 is hardly illustrative of what might happen in the future

I agree but i was replying to a post where it was suggested that a Euro High at that range could not come off...when in fact all the current signs say it is probably 6/4 fav against a 5-1 colder outlook seeing what the current synoptics suggest.

Thats why i said it and actually this is the Model thread:-)

Edited December 7, 2011 by ChartViewer

[cfallon]

Snowmad what do you think thurs/frid is going to bring for us?

Edited December 7, 2011 by cfallon

[Tim Bland]

12z Gfs op is a mild outlier in FI. Majority of ensembles show cool zonality continuing to the end of the run

[cyclonic happiness]

Look at this windmap :o

please stay safe across the whole of these islands guys!

[Great Plum]

12z Gfs op is a mild outlier in FI. Majority of ensembles show cool zonality continuing to the end of the run

Indeed... See,

http://www.netweather.tv/index.cgi?action=charts;type=ens;sess=

Amazing how small the spread is in Aberdeen.zz (with the exception of the op!)

[iceaxe]

is there any chance the forecast storm has been over cooked by the models could it die as soon as it appears on our shores .it has happened before.also will all then snow just be up in the highlands sat above 400 meters as the models are well known for over doing then temps.

is there any chance the forecast storm has been over cooked by the models could it die as soon as it appears on our shores .it has happened before.also will all the snow just be up in the highlands say above 400 meters as the models are well known for over doing then temps.

[danm]

when in fact all the current signs say it is probably 6/4 fav against a 5-1 colder outlook seeing what the current synoptics suggest.

Really? Care to back that statement up? Those are very specific odds you are giving...

[Summer Sun]

ECM tonight

http://www.wetterzen...ics/Recm722.gif

http://www.wetterzen...ics/Recm962.gif

http://www.wetterzen...cs/Recm1202.gif

http://www.wetterzen...cs/Recm1442.gif

http://www.wetterzen...cs/Recm1681.gif

http://www.wetterzen...cs/Recm1921.gif

http://www.wetterzen...cs/Recm2162.gif

Very unsettled snow for some, severe gales and rain also in the mix.

[Gibby]

Good evening. Here's a summarisation of the 12zs from GFS, UKMO and ECM.

GFS shows a very volatile period in its reliable time frames tonight. A very powerful storm will move East over northern Scotland tomorrow bringing damging storm force winds to parts of Southern Scotland. Heavy rain will sweep NE over the North then SE over the rest of Britain tomorrow. after a mild interlude for the South tomorrow cold and wintry showery NW winds return later tomorrow lasting through Friday and Saturday. From then on there are further opportunities for further bouts of severe gales, rain and wintry showers for most areas, worst in the North. In FI rather cold and unsettled conditions persist before High pressure ridges up from the South bringing drier, less windy conditions. It would be somewhat milder too though fog and frost could develop quite widely night and morning if things evolve as shown.

The Ensembles show a very unsettled spell to come with often rather cold uppers over the UK. The operational's trend towards more settled and milder uppers was poorly supported and indeed was a mild outlier in its later stages. In Aberdeen 850's stay remarkably close to normal for most of the run after the sharply lower than average uppers in the next few days.

UKMO shows a very zonal setup tonight with events unfolding similarly to those described in the GFS operational above. As we move into next week the weather remains rather cold and unsettled with low pressure to the North with strong to gale Westerly winds and wintry showers, especially in he North and West.

ECM finally follows in the same theme as the other two, moving it forward to the latter stages of the run as Low pressure digs further South into the UK with cold, windy and unsettled weather persisting throughout.

In Summary the Atlantic Jet stream continues to power storm after storm out of Canada across the Atlantic to deliver periods of high winds, rain and wintry showers to all areas. With very little indication of any upstream changes soon the weather looks like remaining in its sometimes stormy and volatile state for the foreseeable future. However, for weather buffs there is plenty of opportunities for many different facets of weather to show there hand in the next few weeks...definately not boring.

[nick sussex]

You always get good consistency from the models in a zonal pattern, all the output paints a similar picture, very unsettled, milder interludes mixed with the odd cooler day.

Because we've lost that more amplified upstream pattern it will be more difficult to tap into PM incursions and theres always a concern that eventually the Azores high will ridge into southern Europe.

As long as the core of this remains in the Atlantic then it should be a more west to east type zonal pattern rather than the sw/ne jet tilt.

There has been some discussion regarding exactly what sort of pattern we've seen over the last week and what we're likely to see coming up.

The current cooler zonality is likely to turn into the more bog standard variety, colder zonality has one key component sadly lacking from the recent spell, low pressure in that instance generally tracks through central and southern areas, because of this you often see snow events on the northern flank of these and between low pressure snow showers able to reach across the UK.

For colder zonality you either need blocking to the north or ne to divert the jet further south.

We'll have to see whether future output flattens the pattern out even more or whether we can find a bit more amplification to make the medium term a little more interesting.

Edited December 7, 2011 by nick sussex

[south_holland]

The next storm for Monday looks to be more intense and have a greater southern potential than tomorrow's. I will be watching is development with interest.

[Jason T]

The next storm for Monday looks to be more intense and have a greater southern potential than tomorrow's. I will be watching is development with interest.

Agree very turbulant times ahead. Welcome south holland exciting times are about to begin i think.