Model Output Discussion - The Start Of Winter

[Snowman.]

 

The possibilities are endless.

[Penrith Snow]

Most of my optimism is due to the MetO hinting that the potential is there for a prolonged cold spell.

Those boys don't do that in their MRF unless their is reason to do so.

With that in the background I then take more notice of changes in FI charts particularly if they back up this underlining MetO outlook.

No guarantees but there never is and I would imagine that the MetO MRF in early November 2010 used similar language.

Andy

[ITSY]

 

The possibilities are endless.

 

You beat me to it. A chart that literally can take us anywhere. Something brewing...? That Alaskan ridge has shown up a couple of times. If it can develop into an arctic high then the chances of having a HLB from advection in the North Atlantic would increase immensely. A lot to get through before then though at T+384!

[Buxton Codge]

Most of my optimism is due to the MetO hinting that the potential is there for a prolonged cold spell.

 

 

I don't think the Met Office have said anything like this! They have suggested potential for a pattern change at the end of the year with a possibility of some colder weather. Certainly not a prolonged cold spell - happy to be corrected

[TonyH]

i'm constantly reading the word "mild" when referring to the output.

apparently, the last 2 weeks should have been "mild" especially for me in the balmy south. however, its alternated between light rain and cold and frosty and cold. -3c here last night, for example. the other night, the ice was over 1 inch thick in my wheelbarrow. on several days frost has lasted all day in the shade.

it might not be siberia but

its NOT mild!!!!

But the output does show mild/ very mild weather in the coming week!

Please have a look at my detailed weekly outlook (specific to Wales and the Midlands) here:

https://forum.netweather.tv/blog/309/entry-4855-weather-guide-monday-15th-to-sunday-21st-december-2014/

Edited December 14, 2014 by TonyH

[BLAST FROM THE PAST]

But the output does show mild/ very mild weather in the coming week!

It shows a short mild interlude Tony and I think its the use of outlook is mild and very mild as if that is the controlling outlook...it isn't

 

BFTP

[tinybill]

i know its fantasy world   USA  east coast looking its in the deep freeze   all eyes should be what going to happen in the end of December  is that  coming our way !!!!

[Summer Sun]

Snow depth charts from GFS P just coming into range now for Christmas eve

 

This is how it sees things at 19:00 on the 23rd

 

 

Fast forward a few hours to 01:00 on Christmas eve and we can see the area of snow just starting to extend

 

 

Fast forward to 07:00 Christmas eve and some higher parts of the south could see a few flakes, plenty of snow northern and western Scotland

 

 

Precipitation chart for 07:00 Christmas eve shows the snow

 

 

Maximum temps

 

 

Minimum temps

 

 

850's show all the UK under colder air

 

 

So its just a case of wait and see but its nice to see GFS P hinting at something cooler / wintry for the start of the Christmas period

 

[IDO]

The GFS P showing an Alaskan/Polar ridge developing in FI and at D16: 

 

Excellent for the bigger picture but again sends all the initial cold into the US and the UK in the warm sector: 

 

The polar heights on the GFS op don't make it to lower latitude so less amplitude in the NH and the ex-US high ridges to Greenland:

 

 

Similar to the GFS Control where heights merge in Greenland and at D13:

 

   

 

So the theme on the hi-res runs are similar; some amplification. Better for short term cold in the last week of December if the Control is closer to the mark. Though the main cluster out of the two is Alaskan Ridge rather than Greeny ridge and that means at D15 the uppers are average at best:

 

 Lots of variation as to be expected at that range from the rest of the members.

 

 

 

 

 

 

[TonyH]

It shows a short mild interlude Tony and I think its the use of outlook is mild and very mild as if that is the controlling outlook...it isn't

 

BFTP

Not sure that has been proferred though BFTP or did I miss that?  I thought most of us realised the outlook is alternating Pm/Tm the next fortnight. I feel that overall Wales and England is mild in this coming week, thanks to the very mild 48 to 72 hours Tuesday evening through to Thursday night, with the cool rather than cold start and end. You are stressing cold over a mild blip, I see it the other way round

Edited December 14, 2014 by TonyH

[johnholmes]

It shows a short mild interlude Tony and I think its the use of outlook is mild and very mild as if that is the controlling outlook...it isn't

 

BFTP

 

at least Tony produced charts to back up his view, why not do the same then folk can decide which version they believe?

[Cloud 10]

Signals for pattern change remain well on course

 

 

Plenty going on as an antidote to intra day model watching vicissitude. 

　

　

　

　

 

A calming,measured post as ever Tamara,although vicissitude is a word which doesn't come up

very often.

 

Definition of VICISSITUDE

1

a :  the quality or state of being changeable :

 

 

On another note i'm seeing a lot of long range (+360 hrs) ensemble mean anomaly charts being posted on the forum recently,and thanks to some new tools on Meteociel its now possible to pick an individual ensemble member which is a good match for the somewhat diluted ensemble mean chart so as to give a more detailed idea of the possible outcome.

 

So with that in mind here is the +360 hrs (bias corrected) ensemble mean anomaly chart from the 00z GEFS and the ensemble 14 chart for the same time along side.

 

ens.mean..  member 14..

 

This is the best match i could find amongst the individual ensemble members,and whilst not perfect,the main features are pretty well matched, with a trough in Eastern USA,a ridge in the Atlantic/Southern Greenland and a trough over Western Euriope.

 

Below is the normal H500 chart from ensemble 14 which would would certainly provide plenty of interest for the end of the month!

 

Obviously trying to pin down any detail at that timescale is a very difficult exercise,but it is  interesting trying to find an individual chart that best matches those rather vague ensemble means.

 

 

[West is Best]

I've really enjoyed this cold start to winter but anyone else concerned about the persistent and pesky high pressure to our south? It's currently over the Azores, and according to the 06z likely to ridge eastwards across France. This is not where cold lovers want it to be. I won't use the dreaded B word, but what upstream signs do we see that this irritant could shift?

 

p.s. does TEITS post here any more?

[Cloud 10]

I've really enjoyed this cold start to winter but anyone else concerned about the persistent and pesky high pressure to our south? It's currently over the Azores, and according to the 06z likely to ridge eastwards across France. This is not where cold lovers want it to be. I won't use the dreaded B word, but what upstream signs do we see that this irritant could shift?

 

p.s. does TEITS post here any more?

 

He can be found ramping on the previous  page.

Edited December 14, 2014 by Cloud 10

[IDO]

I have noticed the UKMO have updated their first half of January forecast. Basically the most likely scenario is a continuation of the current theme with a lower chance of a cooler more settled period: http://www.metoffice.gov.uk/public/weather/forecast/gcpu5w5gx.

 

So possibly any amplification in the last week of December will be a transient feature, that is assuming it happens, which remains fluid.

[Frosty.]

at least Tony produced charts to back up his view, why not do the same then folk can decide which version they believe?

Most folk on here already know the tide is turning in favour of cold. Heck, I have posted enough charts to back up this view..coldies at last have something to look forward to apart from pressies, mince pies and Turkey. :-)

Edited December 14, 2014 by Frosty.

[West is Best]

So yet another run that hints at a pattern change towards the end of the year with the interest starting from around the 28th Dec onwards.

 

As some of you know I like to look at the Iceland SLP ensembles when blocking to our N is hinted at. However keep an eye on the Madrid SLP mean also.

 

http://max.nwstatic.co.uk/ensimages/ens.20141214/00/prmslMadrid.png

 

Should blocking develop then you would expect low pressure systems to take a more S,ly route and the SLP mean will drop. A few 0Z GEFS members hint at this.

 

Finally as many know my forecasting is based on instinct. Until today I haven't seen anything of interest but my word my mind has now changed towards a mega cold spell arriving at the end of the year.

Thanks for the heads-up Cloud.

 

TEITS: great to see you consistently still ramping it up 

 

Instinct's an interesting one, not very scientific, but interesting nonetheless and whilst in the good ol' days I'd have joined Stratos Ferric is dissing such an approach I'm not quite so sure. I'm not happy about the Azores high, especially the way the 06z shows it ridging east. If that digs in at that latitude we're in trouble. However, returning to your point, and notwithstanding John Holmes's post, so far we have seen a lot of polar maritime air, including a wandering PV, and that gives me cause for optimism.

[Captain Shortwave]

Most folk on here already know the tide is turning in favour of cold. Heck, I have posted enough charts to back up this view..coldies at last have something to look forward to apart from pressies, mince pies and Turkey. :-)

If the trends towards and through Christmas week come off.

The nearer term, this week will vary depending on where you live

Monday

Northern England and Scotland look chilly again as expected, the south is near or slightly above normal with respect to temperatures.

 

Tuesday

Looks the coldest day this week, cold in the north, a little below normal in the south.

 

Wednesday

Scotland only briefly turns milder, England/Wales and Ireland are mild.

 

Thursday

Same as Wednesday, the only difference is that Eastern England looks very mild with 15C possible.

 

Friday

It turns colder from the north west as a cold front clears. Mild at first over England and Wales.

 

Saturday

Back where we started, near normal temperatures in the south and cold in the north.

 

So in that aspect, most in England and Wales would call the reliable timeframe as generally milder than average, those in Scotland would call it a fairly cold week. The ebbs and flows of a typical westerly pattern with alternating tropical maritime and polar maritime incursions. This week overall the trend has always been to be the milder side of average overall as opposed to the first half of December which has been on the colder side.

 

At the present time I expect most of the climatological variables (temperatures, rainfall, sunshine amounts) to come out very near normal. Nothing to change this view which I have had for days really.

[seaside 60]

 

A calming,measured post as ever Tamara,although vicissitude is a word which doesn't come up

very often.

 

Definition of VICISSITUDE

1

a :  the quality or state of being changeable :

 

 

On another note i'm seeing a lot of long range (+360 hrs) ensemble mean anomaly charts being posted on the forum recently,and thanks to some new tools on Meteociel its now possible to pick an individual ensemble member which is a good match for the somewhat diluted ensemble mean chart so as to give a more detailed idea of the possible outcome.

 

So with that in mind here is the +360 hrs (bias corrected) ensemble mean anomaly chart from the 00z GEFS and the ensemble 14 chart for the same time along side.

 

ens.mean..gensbcnh-21-5-360.png  member 14..gensbcnh-14-5-360.png

 

This is the best match i could find amongst the individual ensemble members,and whilst not perfect,the main features are pretty well matched, with a trough in Eastern USA,a ridge in the Atlantic/Southern Greenland and a trough over Western Euriope.

 

Below is the normal H500 chart from ensemble 14 which would would certainly provide plenty of interest for the end of the month!

gensbcnh-14-1-360.png

 

Obviously trying to pin down any detail at that timescale is a very difficult exercise,but it is  interesting trying to find an individual chart that best matches those rather vague ensemble means.

 

 

 

Now that I find very interesting, one that takes in the three charts, very imformative.

I am sure it could be used for mild or cold, however something I would like to see every day.

[The Post-modern Winter]

I have noticed the UKMO have updated their first half of January forecast. Basically the most likely scenario is a continuation of the current theme with a lower chance of a cooler more settled period: http://www.metoffice.gov.uk/public/weather/forecast/gcpu5w5gx.

 

So possibly any amplification in the last week of December will be a transient feature, that is assuming it happens, which remains fluid.

In the interests of accuracy, the Met's outlook states a risk of "colder" weather, not "cooler" as stated by IDO (naturally, I assume this an innocent mistake). Considering the ongoing ruckus pertaining to the subjectivity around what can be defined as mild, I think it only fair to point this out. Let's face it, if the MO were referring to mild temperatures and 'a coldie' came in and changed their working to average temps, I imagine there would be quite an outcry from a select few members. Let's not mislead forum viewers IDO - the potential results of cool and cold airmasses over our tiny island are rather different.

[snowangel32]

I am hope full for a prolonged period of cold, but it concerns me that a week ago the PV looked like heading west, but now that has flipped and the PV looks like basing camp in the states won't this crush any attempt at ridging towards Greenland and also fire up the Atlantic thus putting us in the same position as last year.

Is it a myth that deep cold in america reduces the UK chances .

Edited December 14, 2014 by snowangel32

[ukpaul]

In the interests of accuracy, the Met's outlook states a risk of "colder" weather, not "cooler" as stated by IDO (naturally, I assume this an innocent mistake). Considering the ongoing ruckus pertaining to the subjectivity around what can be defined as mild, I think it only fair to point this out. Let's face it, if the MO were referring to mild temperatures and 'a coldie' came in and changed their working to average temps, I imagine there would be quite an outcry from a select few members. Let's not mislead forum viewers IDO - the potential results of cool and cold airmasses over our tiny island are rather different.

 

In any case, this is the model thread, not the further outlook thread.

[The Post-modern Winter]

In any case, this is the model thread, not the further outlook thread.

Why not mention this to IDO?

[IDO]

In the interests of accuracy, the Met's outlook states a risk of "colder" weather, not "cooler" as stated by IDO (naturally, I assume this an innocent mistake). Considering the ongoing ruckus pertaining to the subjectivity around what can be defined as mild, I think it only fair to point this out. Let's face it, if the MO were referring to mild temperatures and 'a coldie' came in and changed their working to average temps, I imagine there would be quite an outcry from a select few members. Let's not mislead forum viewers IDO - the potential results of cool and cold airmasses over our tiny island are rather different.

 

I was referring to cooler than the other "more likely" scenario, not the actual surface conditions. Apologies, as having reread it it could be misconstrued. 

[ukpaul]

Why not mention this to IDO?

 

I'd already done so by the usual channels.