Model output discussion - 5th December 2016 - Into Winter we go

[West is Best]

5 minutes ago, IDO said:

Christmas Day>

 

So unless I am missing something, f

Even if Christmas Day itself does map out like that, which I think is debatable at 6 days out with this much movement in the patterns, then either side of the day itself is going to feel bitterly cold. Here's for Christmas Eve and Boxing Day.

 

There's a lot to be interested about in these conditions. With much mobility comes potential and we're starting to see some tentative signs for that looking ahead. In the short to medium term there are at least two major storms to the north and considerable hill snow threat.

[chris55]

Well some disturbed and relativity mild weather looks to be on the cards for the xmas weekend, we do have the prospect of colder air digging in behind these lows potentially giving some colder conditions mixed in.

Personally i just hope the timings of these systems allows for some dryer weather Christmas morning so our family walk can go ahead as planned.

Beyond this and into the new year and January lets hope the EC long range is actually proved correct for once, a more blocked pattern to cheer up the after xmas blues would do nicely.

[Jason M]

GEFS out to 240. All 20 ptrbs plus control retain heights to our south / south east. I think that counts as a strong signal!

[gottolovethisweather]

On 16/12/2016 at 10:41, gottolovethisweather said:

That's some serious depth of cold out towards Greenland but will it ever leave their shores. I cannot convince myself to look past the 21st/22nd December right now, but I have a feeling the period immediately around Christmas Day and towards the close of the year will be a memorable one. Everything but the kitchen sink springs to mind, so yes I favour an active period! Snow for some too with not everyone joining in the fun and a lot of transient stuff.

 

 

 

 

 

 

Three days on and we can now approach the festive period with a higher degree of confidence in the forecast.

A significant (memorable?) period of active zonality and not your typical SW'rly type is set to besiege vast areas of the United Kingdom during the festive period. In particular, if I were living in the Northern extremities I would be preparing myself for that "everything but the kitchen sink" reference above. As for the specifics nearer the time stick with the local forecasts and media updates as I think these next ten to twelve days will start getting a lot of media attention. We needn't be fearing for our lives here, but we do need to use a lot of common sense when making travel plans, etc., etc. This prediction of forecast conditions could easily get downgraded in time, but equally, with a ferocious Jet Stream going bananas spinning depressions towards the UK (Tomasz's words not mine) I would at least, keep tuned. Nothing overly mild except brief spells of WAA ridging between the lows, temporary periods of wintry precipitation are on the cards too. Cool to average, little chance for frosts and sustained dry weather, in other words, UNSETTLED being the key phrase to describe our upcoming weather pattern. Down IMBY it might not be much worth writing home about but matters not to me, there is much going on elsewhere for me and others to focus on. TAKE CARE.

Let's see what tonight's ECM makes of the next few days now. 

Edited December 19, 2016 by gottolovethisweather

[IDO]

3 minutes ago, johnholmes said:

So why headline a post and make the comments you have (in your normal manner) when the post to me seems quite an objective one?

Hi.

These setups are pretty much non-events for most, so with all this talk of bitter cold, snow, blizzards, etc, just saying that for many it will not be anything like that. The reason I added it to the other post was that it was an addendum to that post, just putting some meat on the bone. Was not knocking the poster, just adding that there is other weather happening in the UK on that day, not just snow and cold? 

[Ravelin]

GFS 12Z FI los res at the end going for a series of lows diving NW-> SE

[carinthian]

Evening, had to get this x-rated chart out the way from GEM. Still a few mixed signals still from the main models over the Christmas Period. Lets hope UKMO and ECM come to the cold side rescue. However, back here in the Alps, whatever the model charts show over the holiday it looks now bleak for snowfall.I would think now is a safe bet for a mild Christmas for Southern Britain with less uncertainty further north as the depression tracks are still not a done deal but all looks zonal in a SW/to NE direction and with limited cold incurrsions. .

C

[phil nw.]

Just looking at the coming few days and a real pickup in the Atlantic jet is already showing it's hand upstream with the first shot of colder air hitting Scotland by Wednesday.Rain with strong to gale westerlies and quite extensive snowfall for the Highland region by the looks.

These unsettled conditions then extending south through the week. We can see on the gfs for Friday the 2 lows one close to north west Scotland and the next one due to arrive Christmas day just leaving Newfoundland-just look at the strong jet all the way across fed by cold flow off the Arctic Canadian/Greenland area coming south into the milder Atlantic air.

During the transient spells of polar air it will feel quite chilly everywhere with snowfall showing up across higher ground in Scotland  and some other northern areas from time to time.

A very mobile pattern at least until beyond Christmas is now looking odds on with severe weather warnings quite likely for gales from those 2 lows as we get closer to the time.

 

 

 

[Geordiesnow]

20 minutes ago, IDO said:

Christmas Day>>>The 2m temps will be very mild and during daylight hours the winds will be coming from SW bearing westerly:

So unless I am missing something, for most of the UK population a mild and cloudy day with the rain not arriving till later in the day and as for the NW'lies, I am not even sure the south even get a whiff of those? So although the temps will not feel as mild as they show there is nothing that will make us feel "bitter"!

As for snowfall on high ground, to be expected in setups like this, but the window is less than 24 hours before much milder upper air floods the country with a warm sector moving in from the SW late Boxing Day for 48 hours, then rinse and repeat.

All fairly standard December weather and I suppose we are making more of it than it is because this December has been so mild.

It could be the classic of high temps in the morning but getting colder as the day goes on, it all depends on timings in situations like this and its still far too early to pinpoint the details regarding xmas day itself.

Some polar maritime air is in the forecast for this week and into the weekend and whilst it won't be desprately cold, the risk of some snowfall is certainly there.

[West is Best]

6 minutes ago, IDO said:

Hi.

These setups are pretty much non-events for most, 

Given the festive season, let's hope that is the case on this occasion. Because taken at current face value those two storms are anything but 'non-events' for many people up north.

[Frosty.]

20 minutes ago, Ed Stone said:

Not too many GFS straws to clutch there, I am afraid...Over to you, Frosty?

Sorry Ed I used up my supply of straws yesterday..

 

Edited December 19, 2016 by Frosty.

[stewfox]

1 hour ago, Summer Sun said:

 

For clarity GFS 12z gives cold christmas eve, mild start for Christmas day turning colder after 9/10am for majority supporting charts attached. Subject to change of course. A simple 'temps will rise this week', is not correct as we would be at 20c by christmas day.

3pm Christmas Eve

9am Christmas Day

Midnight Christmas Day

3pm Christmas Eve

9am Christmas Day

Midnight Christmas Day

Edited December 19, 2016 by stewfox

[Frosty.]

2 minutes ago, stewfox said:

For clarity GFS 12z gives cold christmas eve, mild start for Christmas day turning colder after 9/10am for majority supporting charts attached. Subject to change of course. A simple 'temps will rise this week', is not correct as we would be at 20c by christmas day.

 

 

Spot on, temps will be up and down from one day to the next or even more frequent than that.

[phil nw.]

WRT temperatures it's always the case in this very fast moving westerly pattern they will vary such a lot day to day with the south never really seeing below average readings,however over parts of Scotland especially highland region there will be some sub-zero temperatures behind the cold fronts. Never easy to give a general picture in such a mobile pattern with the day to day changes of air masses.

[IDO]

3 minutes ago, West is Best said:

Given the festive season, let's hope that is the case on this occasion. Because taken at current face value those two storms are anything but 'non-events' for many people up north.

I was talking in respect to a north westerly PM incursion, not the storms as very few of us want those verifying. 

As for early January, spot the difference between op and control at D16:

[Paul_1978]

2 minutes ago, IDO said:

As for early January, spot the difference between op and control at D16:

Loads of difference!

[Banbury]

Certainly some very interesting options in DEEP FI

[Iceberg]

If we assume for arguments sake that mild is above 0 850s then this shows quite nicely that the mild interludes are quite small and quickly reverted back to normal pm or rpm air. Btw this is from the 12z ens for southern England  

 

Edited December 19, 2016 by Iceberg

[carinthian]

19 minutes ago, carinthian said:

Evening, had to get this x-rated chart out the way from GEM. Still a few mixed signals still from the main models over the Christmas Period. Lets hope UKMO and ECM come to the cold side rescue. However, back here in the Alps, whatever the model charts show over the holiday it looks now bleak for snowfall.I would think now is a safe bet for a mild Christmas for Southern Britain with less uncertainty further north as the depression tracks are still not a done deal but all looks zonal in a SW/to NE direction and with limited cold incurrsions. .

C

Well there we have it from the UKMO for Christmas Day. Much better chart for coldies than the GFS/GEM as the Mid -Atlantic high shows signs of shifting NW . I think the next Low developing off Newfoundland will be the one to watch as it engages some really air and that could track further south than the Christmas Chart. Lets see what ECM come up with. Overall looks like 2016 as the year of no winter for The British Isles. January must start better !

 C

[West is Best]

1 hour ago, knocker said:

I think I was on Ocean Station Juliete at the time.

Wow. I bet that was wild?!

[West is Best]

22 minutes ago, IDO said:

I was talking in respect to a north westerly PM incursion,

I used to be a cynic like you, then the weather came and smacked me round the choppers. This was especially true with polar maritime weather. I used to swear blind that it was useless for snow blah blah. Then it snowed, twice, on Christmas Days in north Devon of all places out of a polar maritime setup.

Ever since then I've shut up and been a bit more circumspect.

These incursions where the PFJ sinks south, as in the current runs, can produce some quite vicious conditions. Hill snow is really very likely over the festive period for the north on these model runs.

Edited December 19, 2016 by West is Best

[Sky Full]

Now I have a little aptitude test for you .....

"Which of the patterns in the grid matches the pattern in the image shown below it?  You have two minutes to answer this question."

Yes... It's a trick question.  The answer is "None of them".   The grid shows the GFS ensembles for the 19th December as modelled on the 9th December.  One or two of the postage stamps have the current high and low pressure systems in roughly the right place but most of the other details of today's actual setup are misplaced, or missing altogether.  However, It seems to me that the weather generated on the ground would not have been vastly different in reality if many of the possible solutions had actually occurred, so the GFS was, broadly speaking, barking up the right tree.   This is how I imagine the 10 day model predictions should be seen - likely to be in the right ballpark with the correct teams playing but with no idea what the actual score will be on the night....

[Geordiesnow]

4 minutes ago, carinthian said:

Well there we have it from the UKMO for Christmas Day. Much better chart for coldies than the GFS/GEM as the Mid -Atlantic high shows signs of shifting NW . I think the next Low developing off Newfoundland will be the one to watch as it engages some really air and that could track further south than the Christmas Chart. Lets see what ECM come up with. Overall looks like 2016 as the year of no winter for The British Isles. January must start better !

 C

Do think some people have short memories on here at times when you see comments like those in bold. I mean the very low minimums parts of Scotland/Northern Ireland and some parts of Northern England(and not just rural areas) during the late part of November/start of December was certainly noteworthy. There has been some frosts elsewhere with the odd night having widespread severe frosts again mainly during November/start of December. And January 2016 was a chilly month at times although that seems to be forgotten about because snow opportunties were fairly limited but  snow did fall quite widely mid month at the time when the infamous coldest night since March 2013 was forecast did not materialise as there was waved weather front became trapped into the flow giving some areas prolonged snow, unfortunately for this area at least, the temps were just on the wrong side of marginal so we only got 2CM's when it could of easily been so much more like other areas recorded. January 2016 could easily of been so different if the blocking just fell favourably for us but it just never really did unfortunately.

So yes 2016 has delivered some winter type weather but it has not delivered a set up which brings upper air temps of -10 or below for more than a day or a widespread level but lets not forget winter type weather does not just mean snowfall.

 

[ArHu3]

3 minutes ago, Sky Full said:

Now I have a little aptitude test for you .....

"Which of the patterns in the grid matches the pattern in the image shown below it?  You have two minutes to answer this question."

Yes... It's a trick question.  The answer is "None of them".   The grid shows the GFS ensembles for the 19th December as modelled on the 9th December.  One or two of the postage stamps have the current high and low pressure systems in roughly the right place but most of the other details of today's actual setup are misplaced, or missing altogether.  However, It seems to me that the weather generated on the ground would not have been vastly different in reality if many of the possible solutions had actually occurred, so the GFS was, broadly speaking, barking up the right tree.   This is how I imagine the 10 day model predictions should be seen - likely to be in the right ballpark with the correct teams playing but with no idea what the actual score will be on the night....

I was meaning to do this, compare ensemble with current setup but I can't find old ensembles on meteociel, do you have a link or were you just so prescient to save images?

[gottolovethisweather]

49 minutes ago, phil nw. said:

Just looking at the coming few days and a real pickup in the Atlantic jet is already showing it's hand upstream with the first shot of colder air hitting Scotland by Wednesday.Rain with strong to gale westerlies and quite extensive snowfall for the Highland region by the looks.

These unsettled conditions then extending south through the week. We can see on the gfs for Friday the 2 lows one close to north west Scotland and the next one due to arrive Christmas day just leaving Newfoundland-just look at the strong jet all the way across fed by cold flow off the Arctic Canadian/Greenland area coming south into the milder Atlantic air.

During the transient spells of polar air it will feel quite chilly everywhere with snowfall showing up across higher ground in Scotland  and some other northern areas from time to time.

A very mobile pattern at least until beyond Christmas is now looking odds on with severe weather warnings quite likely for gales from those 2 lows as we get closer to the time.

 

 

 

6

 

 

Thanks as ever Phil Nw for your input. As others might have missed my post as it lurks at the bottom of the previous page, I'll link to it below. I concur with all that Phil states above. The Jet is about to get big time FIRED UP!

 

Edited December 19, 2016 by gottolovethisweather