The hunt for cold - Model discussion (late November)

[northwestsnow]

Very Unsettled looking EC this morning..

[carinthian]

19 hours ago, carinthian said:

Suns come out. Sparkling day now, deep snow cover and current temp of -5c. Just a few skiers today enjoying the fantastic weather and scenery in the mountains. A bit of an update from over here. Still not 100% sure how things are going to evolve this coming weekend regarding to the British Isles. Model still keeps showing a slight westward correction on each 24 hourly run output. Longer term charts at day 10 still shows a low over the British Isles starting to slowly sink into Europe and height rises to follow towards the NW. By day 15 some very cold air develops ,especially over Northeast Europe. UK looks cold during this period with snow risk more likely over the continent but still too far out to forecast ,but the trend is there. Hope this helps.

c

Morning all, well UKMO has dropped the build of high pressure into the British Isles this morning. All main models looking to have a big slow moving Atlantic Low circulation in place, some way south of Iceland at 144 T. Meanwhile in the shorter term , still some uncertainty in the timing to push the cold air away from the British Isles during the weekend. Beyond 144t , the models throwing all sorts of outcomes into the equation. Certainly chart of the day so far is from the gfs -300t parallel run which brings a snowy Christmas Eve to you lot in Blighty followed by the GEM ops run which is heading for a similar scenario as early as 240t. Think the outcome eventually will be similar to what the model we have over here has been showing for a number of days now and that is for the low to sink slowly into Europe  through the British Isles followed by a rise of pressure to the North or Northwest . Will get an update later this morning on latest thoughts.

[bluearmy]

13 minutes ago, northwestsnow said:

Very Unsettled looking EC this morning..

I wouldn’t commit to anything beyond the weekend nws - the Xmas miracle which is the gfsp this morning isn’t so hemispherically different to the ec op at day 10 .......... 

[northwestsnow]

3 minutes ago, bluearmy said:

I wouldn’t commit to anything beyond the weekend nws - the Xmas miracle which is the gfsp this morning isn’t so hemispherically different to the ec op at day 10 .......... 

Thanks mate.. was in a meeting but just come out and wondered if the jet is showing signs of sinking south day 10...

[Sky Full]

If you want to see snow anywhere other than mountain tops over the weekend, head North and East according to the ICON:

Unless we see some significant changes in the next few days we're unlikely to see any more until after Christmas now.

[carinthian]

51 minutes ago, carinthian said:

Morning all, well UKMO has dropped the build of high pressure into the British Isles this morning. All main models looking to have a big slow moving Atlantic Low circulation in place, some way south of Iceland at 144 T. Meanwhile in the shorter term , still some uncertainty in the timing to push the cold air away from the British Isles during the weekend. Beyond 144t , the models throwing all sorts of outcomes into the equation. Certainly chart of the day so far is from the gfs -300t parallel run which brings a snowy Christmas Eve to you lot in Blighty followed by the GEM ops run which is heading for a similar scenario as early as 240t. Think the outcome eventually will be similar to what the model we have over here has been showing for a number of days now and that is for the low to sink slowly into Europe  through the British Isles followed by a rise of pressure to the North or Northwest . Will get an update later this morning on latest thoughts.

Looking at the ECM pressure anomalie chart 500mbz dam at 240t you would expect the low heights also to start to sink south. however, ECM taking a bit longer to evolve in this particular run.

 C

C

[Midlander]

Good Morning ARPEGE still best for snow potential and has been for a few days don’t know whether that’s a good or bad thing. ICON has backed away unfortunately, until we see the other models like the AROME and HIRLAM I’m not getting too optimistic.

[Yarmy]

Looking at the GEFS panel for T192, there is reasonable support for height rises to our North as advertised by the GFSP.

https://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=6&ech=192

The longwave pattern GFSP at T132 is not a million miles from where the UKMO T144 was last night.

 

 

 

[gottolovethisweather]

11 hours ago, WalsallWeather123 said:

Huge change on ICON in only 6 hours. Thursday will be a nowcasting event. Not one model has a grip on it

 

To be honest, we should expect nothing more, or nothing less when it comes snowcasting. Incidentally, has the forecast not changed again? More focus now on the weekend happenings.

It'll likely be transitional in nature but the cold air is set to stay longer than originally predicted by the NWP suites even just two days ago. By the end of the weekend, it'll be game over and onto looking into the longer-term developments around the Xmas period.

Edited December 12, 2018 by gottolovethisweather

[Catacol]

1 hour ago, northwestsnow said:

Very Unsettled looking EC this morning..

Yes - if you believe in pacific drivers and attempted teleconnective forecasting then dont look at ECM op this morning. Turns into a bit of a horror show.

GFS closer to the mark in terms of attempted surges - but doesnt quite get there.

Good job it is only 12th Dec with time for these NWP models to smell the coffee..... Looks like a bit of snow around end of this week just to whet the appetite!

[booferking]

13 minutes ago, Catacol said:

Yes - if you believe in pacific drivers and attempted teleconnective forecasting then dont look at ECM op this morning. Turns into a bit of a horror show.

GFS closer to the mark in terms of attempted surges - but doesnt quite get there.

Good job it is only 12th Dec with time for these NWP models to smell the coffee..... Looks like a bit of snow around end of this week just to whet the appetite!

FV3 para bang on the money then..

[The Beast From The East]

12 minutes ago, Catacol said:

Yes - if you believe in pacific drivers and attempted teleconnective forecasting then dont look at ECM op this morning. Turns into a bit of a horror show.

GFS closer to the mark in terms of attempted surges - but doesnt quite get there.

Good job it is only 12th Dec with time for these NWP models to smell the coffee..... Looks like a bit of snow around end of this week just to whet the appetite!

Love your Posts by the way and being a skier I'm very jealous when I see your photos lol... 

Although the models don't look so good after the weekend I just look back to earlier in the year when we had the SSW event and I remember you and other members going on about it and that things looked very good for cold and snow in the very near future . The models were having none of it of course and were showing a drab outlook for as far as you could see 10 days + yet suddenly one evening a couple of days later one of the models picked up on it and it was a complete change to a cold outlook and in a short time frame.... Next thing we knew was the Beast was on it's way to the UK... We know what followed... ❄❄❄❄

[johnholmes]

Beyond this week then I can see little within a 14-15 day time frame that would suggest any major change to the predicted upper air pattern in that time is a non starter.

All 3 major 500 mb anomaly charts are on the same page you might say, and this has been a feature over several days. TheEC and GFS have now and then suggested the high level blocking to extend west towards Greenland but still with the strong flow over the Atlantic. NOAA has not shown any of this. As you can see in the links below they are all 3 of the same mind, indeed the 8-14 NOAA carries on with this.

To my non specialist eyes the MJO (GFS version) suggests nothing beyond that to suggest any marked change. So the surface weather over the next 2 weeks, after the end of this week, looks unsettled, quite windy at times. The upper air is sourced from a fairly cold area (NE Canada) so much of the time should see most of the country in Polar type air not Tropical, but obviously with pretty deep and fast moving lows there will be variations. But no signal I can see for anything other than transient deepish cold air.

http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

[carinthian]

2 hours ago, carinthian said:

Morning all, well UKMO has dropped the build of high pressure into the British Isles this morning. All main models looking to have a big slow moving Atlantic Low circulation in place, some way south of Iceland at 144 T. Meanwhile in the shorter term , still some uncertainty in the timing to push the cold air away from the British Isles during the weekend. Beyond 144t , the models throwing all sorts of outcomes into the equation. Certainly chart of the day so far is from the gfs -300t parallel run which brings a snowy Christmas Eve to you lot in Blighty followed by the GEM ops run which is heading for a similar scenario as early as 240t. Think the outcome eventually will be similar to what the model we have over here has been showing for a number of days now and that is for the low to sink slowly into Europe  through the British Isles followed by a rise of pressure to the North or Northwest . Will get an update later this morning on latest thoughts.

Another push back in the timing of the Atlantic frontal movements across the British Isles. All a messy picture for Saturday looking at the latest picture below. Latest 84t fax run also shows a further delay in timing. 

C

[Coopsy]

20 minutes ago, carinthian said:

Another push back in the timing of the Atlantic frontal movements across the British Isles. All a messy picture for Saturday looking at the latest picture below. Latest 84t fax run also shows a further delay in timing. 

C

A 500 plus mile line of snow and the only place with rain is the SE.... I need to move

[snowrye]

3 minutes ago, c00ps said:

A 500 plus mile line of snow and the only place with rain is the SE.... I need to move

Its frustrating to say the least

[frosty ground]

24 minutes ago, snowrye said:

Its frustrating to say the least

There won't be much snow up north either so you won't be missing much.

[Sweatyman]

52 minutes ago, johnholmes said:

Beyond this week then I can see little within a 14-15 day time frame that would suggest any major change to the predicted upper air pattern in that time is a non starter.

All 3 major 500 mb anomaly charts are on the same page you might say, and this has been a feature over several days. TheEC and GFS have now and then suggested the high level blocking to extend west towards Greenland but still with the strong flow over the Atlantic. NOAA has not shown any of this. As you can see in the links below they are all 3 of the same mind, indeed the 8-14 NOAA carries on with this.

To my non specialist eyes the MJO (GFS version) suggests nothing beyond that to suggest any marked change. So the surface weather over the next 2 weeks, after the end of this week, looks unsettled, quite windy at times. The upper air is sourced from a fairly cold area (NE Canada) so much of the time should see most of the country in Polar type air not Tropical, but obviously with pretty deep and fast moving lows there will be variations. But no signal I can see for anything other than transient deepish cold air.

http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

Not a nice read

[Met4Cast]

This mornings EPS if anything have further muted the signal for Saturdays snowfall potential

ICON/APERGE in broad agreement with risk of snow largely across Scotland/Northern Pennines, perhaps falling to lower levels in regions surrounding these areas for a short time but much of Southern and Central England as things stand this morning unlikely to see much in the way of excitement, milder air unfortunately comes up in Southerly winds ahead of the approaching & slowing frontal system. 

This evening 12z FAX charts will be of interest, ideally you want to be North of the point where the warm front connects to the cold and occluded systems. If you're South and West of this front when it moves in, you're most likely going to be seeing rain.

[swfc]

1 hour ago, johnholmes said:

Beyond this week then I can see little within a 14-15 day time frame that would suggest any major change to the predicted upper air pattern in that time is a non starter.

All 3 major 500 mb anomaly charts are on the same page you might say, and this has been a feature over several days. TheEC and GFS have now and then suggested the high level blocking to extend west towards Greenland but still with the strong flow over the Atlantic. NOAA has not shown any of this. As you can see in the links below they are all 3 of the same mind, indeed the 8-14 NOAA carries on with this.

To my non specialist eyes the MJO (GFS version) suggests nothing beyond that to suggest any marked change. So the surface weather over the next 2 weeks, after the end of this week, looks unsettled, quite windy at times. The upper air is sourced from a fairly cold area (NE Canada) so much of the time should see most of the country in Polar type air not Tropical, but obviously with pretty deep and fast moving lows there will be variations. But no signal I can see for anything other than transient deepish cold air.

http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

Moring John.Im not familiar with the 500mb charts but are they subject to quick changes in the atmosphere ie whats been touted ete on the run up to xmas- new year .tia

Edited December 12, 2018 by swfc

[Tim Bland]

Break in lows allowing for a ridge in the Atlantic ? Some WAA behind it..or is it wishful hopecasting ? Certainly wouldn’t take much from this position to start the next hunt? 

Edited December 12, 2018 by Tim Bland

[Weathizard]

Something to keep an eye on... probably get flattened in GFS Fi though

[frosty ground]

Been in and out of the Op runs for a few days 


lack of cold to the east is the issue.

[Met4Cast]

6 minutes ago, frosty ground said:

Been in and out of the Op runs for a few days 


lack of cold to the east is the issue.

Lack of sustained blocking is the issue, given the right pattern cold will flood into Europe very, very quickly 

[weirpig]

Latest Arpege  similar to its 0z run   Saturday Morning the front turning to snow as it hits Wales.  Not going to ba alot i would have thought  but still nice to see