winter model discussion Winter Model Discussion 06Z 17/02/13 onwards.

[london-snow]

Calm down ,lol its only the o6 run it's always the worst run of the 4 runs of the gfs EVERY day I've never seen the later 12z run match the 06 run in all the years I've been model watching.I would wait until at least the 12 z runs and the shorter time scale higher resolution models,before writing of the cold spell completly,lol

Hence my load of lols in the post sleety.

Whatever the weather be it cold and snowy or cold and dry i am happy with either as they both have great benefits.

Edited February 19, 2013 by london-snow

[Harsh Climate]

Looking at the 00z esembles some very cold perpetrations around 1st march

This place would errupt if the 12z was to show one of these on the control/operational runs Still a long way out though..

Edited February 19, 2013 by Harsh Climate

[nicknacknoo]

One heck of a difference in deep FI though!

[Frosty.]

Just thought I would run a comparison between the Ecm 00z and Gfs 06z at T+240 hours, as we can see, the ecm shows the anticyclone in absolute control, it's a very powerful looking feature on the ecm and the uk would be cold and frosty but probably sunny by day and with freezing fog being a significant hazard as winds look light and variable, the Gfs 06z shows the high slipping away southeastwards and then a gradual trend towards milder and more unsettled but then turning colder and continuing unsettled with more of a polar maritime type flow, I still think there is an outside chance of an arctic outbreak during early march with strong height rises around greenland/iceland by then or possibly further west.

As for the rest of this week into next week, we are still waiting for the cold scandinavian air to arrive but it will begin to flow in tomorrow as a weak front spreads in from the east with a little rain or drizzle on it, temps tomorrow between 4-8c, the really cold air follows in from thursday onwards, especially across the south with some snow flurries for the south and southeast but becoming mainly dry elsewhere with variable cloud and sunny spells, lighter winds further north with widespread frosts and some fog, the south breezier but with very cold uppers making it feel sub zero by day, eventually the calmer weather in the north and west will cover all areas by the middle of next week.

Edited February 19, 2013 by Frosty039

[No Balls Like Snow Balls]

Quite clearly a lot of scatter on the 06z ens from the 27th/28th onwards. Maybe some of the colder ensembles show HP in Greenland ( I can't be bothered to look lol). I think despite the scatter my opinion is that the HP will sit over us or just to the West of us ala ECM and GFS until at least the end of next week, unfortunately I do not see the HP setting up over Greenland.

Edited February 19, 2013 by No balls like Snow Balls

[Gowon]

The ECM control goes cold again towards the end.

The CMA also shows high pressure trying to build to our NW again at the end.

[fergieweather]

EC agrees with UKMO-GM re sharper trough Saturday; some dynamic snow across C-E parts of England; mostly inconsequential amounts but perhaps local impacts based on current UK4 accumulations. That aside, broader story still consistent re light flurries on other days through to early next week with anticyclonic influence and waning easterly (with markedly dry signal in ensembles) remaining until end of Feb. Cyclonic and less cold story early March, albeit northerly flow in some solutions means cautionary approach re any promise of 'milder'.....

[stratty]

......first signs of a Thames streamer for Friday am? (usual caveats apply!)

http://europa.buienradar.nl/3daagse.aspx

Edited February 19, 2013 by stratty

[Guest]

The ECM control goes cold again towards the end.

The CMA also shows high pressure trying to build to our NW again at the end.

The 00z GFS ensembles were showing a scatter of pressure for Iceland, although the scatter (bar one member) is all on the high side at its peak around the 27th. Postage stamps don't show many (if any) Greenland highs; on some of the perturbations the heights seem to move towards Canada if anywhere (west based -NAO).

Edited February 19, 2013 by CatchMyDrift

[Gowon]

The 00z GFS ensembles were showing a scatter of pressure for Iceland, although the scatter (bar one member) is all on the high side at its peak around the 27th. Postage stamps don't show many (if any) Greenland highs; on some of the perturbations the heights seem to move towards Canada if anywhere (west based -NAO).

Cool... at least we know it won't be a sinker, maybe we could get lucky and finally see it migrating to Greenland.

I know it's the BOM, but this would be nice (for cold lovers)

[chris55]

Perturbation 1 from GEFS is a thing of beauty. All just a bit of fun though posting the charts, but blimey this would be epic.

High moving up to Greenland,

Northerly coming down, cold uppers!

Cold air floods south

Channel low approaching,

Channel low delivering,

second Low approaching,

[SLEETY]

One of the best runs I have ever seen,chris,almost too severe,lol

The met are even talking about a chance of a northerly Fergie has mentioned

Could about to get very interesting soon!

[bluearmy]

A fair refelction of where we are when unsupported gefs members are wheeled out as the best output. if you are desperate for a wintry run, i can photo shop a better one than that. (or maybe look through the archives at 47 /63/ 79).

seriously, if a gefs member is worth posting on this thread in detail, it has to be part of a close cluster.

thats the glass nearly empty post.

the glass half full one says that the member shown has around a 1 in three chance of verifying in that broad solution, looking through the individual runs.

[chris55]

A fair refelction of where we are when unsupported gefs members are wheeled out as the best output. if you are desperate for a wintry run, i can photo shop a better one than that. (or maybe look through the archives at 47 /63/ 79).

seriously, if a gefs member is worth posting on this thread in detail, it has to be part of a close cluster.

thats the glass nearly empty post.

the glass half full one says that the member shown has around a 1 in three chance of verifying in that broad solution, looking through the individual runs.

Just a bit of fun Nick as stated Not to be taken in any kind of a forecasting sense.

Edited February 19, 2013 by chris55

[snowking]

A fair refelction of where we are when unsupported gefs members are wheeled out as the best output. if you are desperate for a wintry run, i can photo shop a better one than that. (or maybe look through the archives at 47 /63/ 79).

seriously, if a gefs member is worth posting on this thread in detail, it has to be part of a close cluster.

thats the glass nearly empty post.

the glass half full one says that the member shown has around a 1 in three chance of verifying in that broad solution, looking through the individual runs.

0z and 6z GFS ensemble means still keen on our race between the Atlantic and Scandinavian cyclogenisis - the Atlantic still being progged to win at present but bearing in mind the constant over modelling of the Atlantic jet stream thus far this year, we could be seeing a new trend emerging.

Incidentally 0z GEM mean has moved towards this solution too, with the common theme being the Greenland heights.

To counter that, we also have to bear in mind that the Greenland high has been continuously progged this winter, and has yet to actually show it's face (and without this, the Atlantic cyclogenisis will have nothing holding it back or forcing it south - will we finally see the low heights from that Canadian/Greenland PV lobe clear?!)

Will post in more detail after the 12z's

SK

Edited February 19, 2013 by snowking

[Frosty.]

The latest met office update in the 6-15 day range is closer to the gfs 06z than the Ecm 00z, the 6z shows the main anticyclone slowly drifting away southeastwards with less cold/milder and more unsettled weather then pushing in from the west, this is also how the MO currently see it, so perhaps the ECM is overdoing the anticyclonic influence by T+240 since on the 00z it strengthened the high in that range rather than weakening it. I still think there is a little bit of support for an arctic outbreak during the 1st or 2nd week of march but nothing in the met office wording even hints at that possibility.

[nick sussex]

If the high is going to retrogress it looks like it will be through a very complicated route. And its still a longshot because of how complicated it is. Looking at some of the GEFS I've seen easier ways to retrogress a high.

So the GFS teases with energy trundling around the top of the high then the high moves west but you're still facing a race against time to get the northerly in before the pattern wants to develop a western based negative NAO.

There is decent ensemble support for a lobe of the PV to drop se to the east but its still a longhaul to get the favourable jet curveback to bring that towards the UK.

I suppose one positive from the models is that the high slipping se looks unlikely and there seems enough energy in the Med to buy some time in the hope that the upstream pattern becomes a bit more favourable but for the timebeing a decent retrogression of the high with Arctic blast hitting the UK is still a low probability.

We'll see over the next few runs whether those chances increase, earlier still uncertainty with snow potential but theres still a chance things there could turn a bit more favourable.

[Frosty.]

Well apparetly yesteday the meto were hinting at a northerly in the long term!!they as clueless as us!!

The thing is though, the Ecm is currently less likely to eventually deliver a Northerly since by T+240 the high is even stronger and completely controlling the uk weather, a vice like grip and any changes from there would be snail like slow, at least the gfs subsides the high and we can move forwards, milder and more unsettled but then maybe colder and unsettled, as the 6z op run.

[Man With Beard]

Remarkable model agreement again today in the early-mid range. Considering that prospects for the UK this week are virtually unchanged from model output mid-last week, it represents the best model performance of the winter. Very surprising when you think we are entering an easterly phase, which historically have led to lots of flip-flopping. Trouble is, I think many of us are hoping for a bit more flip-flopping at the moment. I readily admit I have been expecting more movement in the model output, which was why I haven't given up hope in a more general risk of snow through England and Wales - looks more and more as if we will need localised developments now - troughs developing over the North Sea, increased convective possibilities, convergences, streamers. But a substantial drop in heights during the coldest spell probably has to be discounted now.

[summer blizzard]

A beauty. I'd expect with such pressure and a strengthening sun inland you'd probably see the cloud burn back.

[Snowman.]

A beauty. I'd expect with such pressure and a strengthening sun inland you'd probably see the cloud burn back.

Would like it in June but recent year have taught me that having a warmer spring leads to a crap summer.

A normal spring would be nice so its more likely we will get a Decent summer.

[Chris K]

Would like it in June but recent year have taught me that having a warmer spring leads to a crap summer.

A normal spring would be nice so its more likely we will get a Decent summer.

Recent years perhaps that has been a trend, but can we really say that a warmer spring is more likely to lead to an unsettled Summer? Will be interesting to see if it persists but discussion for another thread perhaps..so I'll zip it.

So..although this strong high pressure is slapped right over the UK on the latter frames of the this mornings ECM run, it is still looking at 7 days away. I'd imagine there will be some changes by then even if its the tilt/shape/position etc. If not that would be very good consistency...we will see!

Not that I'd complain if it did verify!

Edited February 19, 2013 by Chris K

[legritter]

I still think some surprises could pop up but we need some luck .looking at modells the high could be around our shores for a while ,and winter in my opinion will be lurking like some of our posters so interesting times still .my wife insists i get off computer and into the garden ,whooooosh see you all later ,

[Snowman.]

Recent years perhaps that has been a trend, but can we really say that a warmer spring is more likely to lead to an unsettled Summer? Will be interesting to see if it persists but discussion for another thread perhaps..so I'll zip it.

So..although this strong high pressure is slapped right over the UK on the latter frames of the this mornings ECM run, it is still looking at 7 days away. I'd imagine there will be some changes by then even if its the tilt/shape/position etc. If not that would be very good consistency...we will see!

Not that I'd complain if it did verify!

What ever the out come is its a good one.

GH cold and snowy!

Settled warm and sunny!

Don't see the Atlantic anywhere.

[jam]

A beauty. I'd expect with such pressure and a strengthening sun inland you'd probably see the cloud burn back.

What sort of night time temperatures could be achieved with this set up, assuming no snow cover?