Winter Model Discussion - The Hunt For Cold - 10th Dec

[bluearmy]

again we have differences off the eastern seaboard on gfs within semi releiable timeframes. this time there is much more energy available as the departing vortex sends some -24c uppers down towards newfoundland. the system in the west atlantic as we approach the end of high re is therefore deeper than might have been expected. retrogress the whole pattern somewhat and promising charts become decent charts as thr trough disrupts over us rather than to our east

[UV-RAY]

How often are these correct. I personally don't believe them one bit

IMO, these will be nearer the mark then any hopecasting and teleconnections, in fact I think that only leaves the Beijing model predicting + heights over Greenland and that was on last months update.

[snowmadchrisuk]

One thing I have noticed is within 120 that high to the east just keeps increasing in strength and size

6Z

12z

Also worth noting that there was a large increase in this from the 00z to 6z as well.

Well spotted, Any low pressure development to our SE could end up undercutting it and we would be right back in the game, I will go through the ensembles in a minute and see if any go for it .

[Cheshire Freeze]

IMO, these will be nearer the mark then any hopecasting and teleconnections, in fact I think that only leaves the Beijing model predicting + heights over Greenland and that was on last months update.

Yes signifficant long range model guidance now of low heights around Greenland as a mean throughout the Jan-Mar period. I think the one thing that could throw this projection way off is a SSW event, which I'm very doubtful any of the LR models could foresee.

This will be winter 12/13's wildcard I think but by no means a guarantee.

Edited December 10, 2012 by CreweCold

[bradymk]

http://www.weatherweb.net/wxwebtvfeatured.php?code=YWGDiiuTGcM <<<<< link interesting longer range video today from Simon Keeling, I think he isnt to far off the mark here with cool end to december and start off january to a more colder set up after the first week of Jan. He has been good recently and the charts he shows are performing relatively well. Shorter term, i think its time to move on regarding the end of the week Edited December 10, 2012 by bradythemole

[Weathizard]

Another run with potential but not quite making it, frustrating work at the moment but we plough on in our quest for the pot of gold. I'm still encouraged by developments within 72-96 anyway, need the system to go as far south as possible for the possibility of an undercut. Unlikely but still possible at this stage with the low trending further south.

[Panayiotis]

Hopecast?

Edit:Woo it happened at 252hrs! Fi though!

Edited December 10, 2012 by panayiotis

[lorenzo]

Looking at the NH view of the Jet profile that Aleutian high and the gradient provided between it and the Vortex really boosts energy within the Jet, this then meets no resistance / variance until booming round towards the monster block to our East, with the UK the last stop for the extra energy in the Jet. For speed of change, let's hope for a tropical kick to the pattern from Mr MJO.

[LomondSnowstorm]

Interestingly the METO Glosea4 model has been updated today for the period Jan/Feb/Mar.....look away if you're a coldie....

Bartlettesque I would say

Has the model been upgraded since the 2009/10 winter when it predicted similarly mild temperature anomalies across the UK only for it to be completely wrong? I don't have a huge amount of faith in long range models as a rule though it's worth taking all available evidence into account.

[snowmadchrisuk]

Another run with potential but not quite making it, frustrating work at the moment but we plough on in our quest for the pot of gold. I'm still encouraged by developments within 72-96 anyway, need the system to go as far south as possible for the possibility of an undercut. Unlikely but still possible at this stage with the low trending further south.

Pv is really displaced on thsi run , Infact any further Southward movement of that segment of the Polar Vortex , the Vortex itself could provide an undercut , have a feeling the Cold runs will be back very soon, The Greenland area just doesn't look conductive to a raging P/V at all, I have a feeling were right round the corner from something here .... Initial strat movements were also suppose to have an effect around the second week of December :?)

[snow drift]

Well the crumb of comfort out of the GFS for me, is that out in FI it looks more like the ECM this morning with hieghts being suggested to our NW all tho more north than the ECM. Apart from that and booking to fly to Stockholm, I have little to add.

[Timmytour]

In all the varieties of FI that GFS has served upon us, it has remained consistent regarding the diminishing heights over Siberia from around the 20th December

[Buriedundersnow]

Looking at the NH view of the Jet profile that Aleutian high and the gradient provided between it and the Vortex really boosts energy within the Jet, this then meets no resistance / variance until booming round towards the monster block to our East, with the UK the last stop for the extra energy in the Jet. For speed of change, let's hope for a tropical kick to the pattern from Mr MJO.

could u plz post a link to that

[pistolpetes11]

I wonder if someone can answer a question while it's quiet.

Do other weather fans on forums at other locations in the world go through the same emotions run to run like we do?

Would someone from Milwaukee for example, who lets say is a massive snow fan, see T240 showing blizzards and automatically know with a fair degree of certainty that this or that weather chart will come to fruition? obviously location is perhaps key here but I hope you get my drift.

Basically do the models ever get things very accurate / spot trends better for certain locations around the globe?

On an Irish site I use , nearly the exact same , but with the disappointment so what more muted

[kold weather]

The Atlantic pattern is putrid despite other more promising signs, I think we are going to need the PV to totally breakdown for us to reset into a pattern that is gonig to give lasting cold, its clear we are in a set-up where depsite having a decent -ve AO the jet is still strong enough and flat enough to cause major issues.

[LomondSnowstorm]

Was this model used for our bbq summer?

I just checked, it became operational in September 2009 so it must be the one that was operational for both the 2009/10 winter and the 'bbq summer' of 2010 that forced the Met Office to stop issuing long range forecasts. That's not to say it's necessarily wrong of course but it's by no means infallible, just like any other model, and I personally feel we're still at the stage (and are always will be to some extent) where human input for long range forecasts is far more valuable than just using the raw long range output itself.

[Buriedundersnow]

Has the model been upgraded since the 2009/10 winter when it predicted similarly mild temperature anomalies across the UK only for it to be completely wrong? I don't have a huge amount of faith in long range models as a rule though it's worth taking all available evidence into account.

do u not think these long range models tend to go on what its like when they come out the long range models were showing for cold in winter in october and we were cold then into november we got a little milder and the charts for that month on the long range had flipped to a warmer outlook

[Barry12]

I wonder if someone can answer a question while it's quiet.

Do other weather fans on forums at other locations in the world go through the same emotions run to run like we do?

Would someone from Milwaukee for example, who lets say is a massive snow fan, see T240 showing blizzards and automatically know with a fair degree of certainty that this or that weather chart will come to fruition? obviously location is perhaps key here but I hope you get my drift.

Basically do the models ever get things very accurate / spot trends better for certain locations around the globe?

The uk is a lot harder for the models due to us being an island, having warm water around us etc.

[Isolated Frost]

The first 8 days of December anomaly- GP looking good for his word if I do say so and anomalies suggest the next 8-14 days will be very similar- good work so far Stu!

Timmytour- the above should explain that; a transfer of stratospheric energy towards Siberia as heights become conductive to rises around Baffin once more; the profile for a SSW around early January is most certainly possible

The tendency for a drop in zonal winds in the mid-stratosphere at 60N for D8/D9 has been consistent past recent days

[Frosty.]

it's just stalling LP over or just to the east of us.....we just sit in mild Atlantic air.

It doesn't look mild to me, look where the polar front jet is well south of the BI.

cool zonal effectively with winds from the north atlantic, temps around 6-8c which is not mild, of course we will have milder intervals as warm front sectors push east but brief digs of colder air once the cold fronts clear, pretty sad really considering what we were hoping for but it's crystal clear that we will be going into a less cold more average wet and windy outlook with a fired up atlantic from around thurs/fri.

Edited December 10, 2012 by Frosty039

[Summer Sun]

Tonight's GFS run shows a period of sleet and snow before turning back to rain in the south west, wales and midlands later this week with parts of western Scotland as well

Into early next week temperatures look like falling away again for the north so over the high ground snow is possible

An early look to Christmas day and away from the south west its a cold one

[Cheshire Freeze]

The first 8 days of December anomaly- GP looking good for his word if I do say so and anomalies suggest the next 8-14 days will be very similar- good work so far Stu!

Timmytour- the above should explain that; a transfer of stratospheric energy towards Siberia as heights become conductive to rises around Baffin once more; the profile for a SSW around early January is most certainly possible

The tendency for a drop in zonal winds in the mid-stratosphere at 60N for D8/D9 has been consistent past recent days

The anomaly chart doesn't tell the whole story though does it IF and if I remember rightly the analogues touted suggested a larger focus upon the blocking over Greenland, with it being a rather signifficant player in the weather experienced in the UK vicinity, a Scandi high wasn't in even in the running at one point? I also suggest that if current projections come to fruition we won't be looking at a ~2C negative anomaly in regards to the temperature; high night time minima under cloud cover would most likely preclude this.

[Cheshire Freeze]

It doesn't look mild to me, look where the polar front jet is well south of the BI.

Splitting hairs. I think we know what I mean by mild in this instance.......upper air not supportive of snow (except maybe the highest UK peaks),of Atlantic origin and brought about on a brisk wind.

[Frosty.]

The Atlantic pattern is putrid despite other more promising signs

spot on kold, it's a return of average uk winter weather so we again have to make do with chasing cold FI charts yet again, like we do for 90% of winter anyway. Having said that, there are more promising signs that could bring a cold surprise out of nothing in the next few weeks, if the charts can just collapse the cold like they obviously have, surely they can do the opposite as well.

Splitting hairs. I think we know what I mean by mild in this instance.......upper air not supportive of snow (except maybe the highest UK peaks),of Atlantic origin and brought about on a brisk wind.

not really, mild is 11-13c +, average is 8-10c, cool is 6-8c,

[Snowly does it]

spot on kold, it's a return of average uk winter weather so we again have to make do with chasing cold FI charts yet again, like we do for 90% of winter anyway. Having said that, there are more promising signs that could bring a cold surprise out of nothing in the next few weeks, if the charts can just collapse the cold like they obviously have, surely they can do the opposite as well.

not really, mild is 11-13c +, average is 8-10c, cool is 6-8c,

A little high Frosty I'd say. Average for December is 6/7, for Jan 5/6 as maxima

Edited December 10, 2012 by snowmaiden