Model Output Discussion 4th Dec.2013-12z onwards.

[Frosty.]

According to the GEFS 06z mean, as we approach christmas the weather pattern looks increasingly disturbed with frequent bouts of wet and windy or possibly stormy weather at times with the jet tending to dig further south which increases the risk of cold zonality eventually gaining the upper hand, the mean trends progressively more unsettled with the PFJ slowly descending further south with time and there is much less anticyclonic influence on the latest perturbations than on previous days..much more unsettled, even a chance of a white christmas from P19.

[gottolovethisweather]

Milder in the North from today and for a few days hence but nothing astonishingly warm, i.e. a few degrees above average. Down in the Southern part of the UK (which was what my original comment was based on, some 30 posts in less than hour back now) Temperatures will be favouring slightly milder than average IF the sun shines. From the weekend onwards, increasing potential for colder interludes.

 

 

CAN WE PLEASE DISCUSS THE MODEL OUTPUTS FROM HERE ON IN AS I WOULD LIKE TO READ ENGAGING CONTENT, NOT COUNTLESS POSTS CONTAINING ONE-LINERS OR QUICK-WITTED REPLIES. *THIS ISN'T TWITTER WHERE WE'RE RESTRICTED TO A CERTAIN NUMBER OF CHARACTERS PER POST.

 

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What's the latest? perhaps this may assist once again. http://forum.netweather.tv/topic/78671-model-output-discussion-4th-dec2013-12z-onwards/?p=2859062

 

Edited December 10, 2013 by gottolovethisweather

[MPG]

Only in so much as you posted the GFS predicted max charts to make your point re future temps, but as today proved these can easily be 4 or 5c out.  IF that is the case what looks like normal or rather mild maxima actually turn out to be very mild maxima.

Im not talking about weather observations. Im talking about what the charts show and theres no denying that. You say the temps can be 4 or 5c out, what do you base that on? The GFS always undercooks the tempertures by that amount?? Thats the difference between rain and snow, surely the model cant be that bad. Please provide GFS actual temps against forecasted temps for a period of time, id love to see how bad it really is.

 

At the end of the day, if the models are predicting 6 c in 4 days time, that is what a forecast is based on. Would you then add or subtract 4 or 5 degrees Shed?

[gottolovethisweather]

Im not talking about weather observations. Im talking about what the charts show and theres no denying that. You say the temps can be 4 or 5c out, what do you base that on? The GFS always undercooks the tempertures by that amount?? Thats the difference between rain and snow, surely the model cant be that bad. Please provide GFS actual temps against forecasted temps for a period of time, id love to see how bad it really is.

 

At the end of the day, if the models are predicting 6 c in 4 days time, that is what a forecast is based on. Would you then add or subtract 4 or 5 degrees Shed?

 

Please send a PM to the recipient rather than clog up this thread.

[snowmadchrisuk]

Where have all the posters gone that said we were going to be stuck in a bartlet setup till mid January.... With a PV so strong we were always going to get Atlantic influence. Cold zonality looks a very possible solution for the next couple of Weeks, and I keep noticing them height's trying to build around scandi again , and this time with low pressure further South we would be in a much better position to get an undercut ... I expect we wills tart to see a few more Colder ensembles and ops over the coming days. 

[MPG]

Where have all the posters gone that said we were going to be stuck in a bartlet setup till mid January.... With a PV so strong we were always going to get Atlantic influence. Cold zonality looks a very possible solution for the next couple of Weeks, and I keep noticing them height's trying to build around scandi again , and this time with low pressure further South we would be in a much better position to get an undercut ... I expect we wills tart to see a few more Colder ensembles and ops over the coming days. 

Excellent post. More prospect of colder conditions in the output that any mild.

[nick sussex]

After seeing the ECM operational run I was hoping to see a better set of ECM ensembles so that's disappointing. The rest of the 00hrs outputs are underwhelming from a cold perspective. My horror rating was threatening to go upto 9.5/10, however the ECM operational and GFS06hrs trend in its lower resolution have shaved that down to 8/10!

 

The more positive ECM output still remains marooned at T216 and 240hrs and we'll see this evening whether this moves a little closer. Regardless of the ensembles troughing digging further south over the UK does correlate with pressure building to the east and ne.

 

The first step out of this zonal mild is to at least get that to verify,then upstream its key that theres more amplification to help carve a bit more sharpness to that trough. As I said last night a more festive feeling Xmas is reliant on the ECM calling the trend correctly, that really is now our only hope!!!

[shedhead]

Im not talking about weather observations. Im talking about what the charts show and theres no denying that. You say the temps can be 4 or 5c out, what do you base that on? The GFS always undercooks the tempertures by that amount?? Thats the difference between rain and snow, surely the model cant be that bad. Please provide GFS actual temps against forecasted temps for a period of time, id love to see how bad it really is.

 

At the end of the day, if the models are predicting 6 c in 4 days time, that is what a forecast is based on. Would you then add or subtract 4 or 5 degrees Shed?

That would depend largely on the airstream MPG, but as a good rule of thumb only assume GFS maxima are correct or to low in Winter if fog and especially freezing fog is present. 

 

As for adding a +/- value in winter, 4 or 5 degrees is at the extreme end of the spectrum, but as today has proven infinately possible. In the current airstream or one directly from the SW a 1-3c correction would probably cover the vast majority of situations, but you also need to consider topography as GFS does not handle local effects particularly well and as can easily 5c and more out.

 

Clearly GFS does not always undercook winter temps, but in my experince it does so far more times than it overcooks them.

Edited December 10, 2013 by shedhead

[gottolovethisweather]

That would depend largely on the airstream MPG, but as a good rule of thumb only assume GFS maxima are correct or to low in Winter if fog and especially freezing fog is present. 

 

As for adding a +/- value in winter, 4 or 5 degrees is at the extreme end of the spectrum, but as today has proven infinately possible. In the current airstream or one directly from the SW a 1-3c correction would probably cover the vast majority of situations, but you also need to consider topography as GFS does not handle local effects particularly well and as can easily 5c and more out.

 

Clearly GFS does not always undercook temps, but in my experince it does so far more times than it overcooks them.

 

And a PM back to MPG from you Shed would have been good, yes it is an interesting debate but not one I want to read some twenty posts about. Nevertheless, CAN WE NOW ALL MOVE ALONG PLEASE, NOTHING TO SEE READ HERE.

 

Thanks Nick S for your insight, perhaps a new trend is finally starting to unravel, the next suite of runs from all NWP outputs and most probably also Wednesday's will finally provide something productive.

Edited December 10, 2013 by gottolovethisweather

[Chris K]

 

Those of us who quoted these potential localised maxima last week got rather slated, not least because rather too much store is set in what GFS predict. 

 

I think it was more to do with the fact people were saying we'd be locked into a pattern of H Pressure limpeting over C europe for 2-3 weeks and some even saying  5 weeks+.

 

It was pretty clear a mild spell of weather was incoming when the models were being consistent in showing so for this week. The fact there are differences in outputs as close as later on this weekend is proof really that no matter what solutions are being shown from the outputs (be it mild or cold)...it is simply unreliable to look that far ahead. A couple of days ago the runs were showing a limpeting high pressure right from start to finish!

 

I'm not saying it is now suddenly showing cold weather coming to our shores, but there does seem to be even more emphasis now of a change in weather as we head into next week - perhaps to a more unsettled 'tad cooler' phase.

[Frosty.]

The Ecm 00z ensemble mean shows the weather trending more unsettled and windier with spells of persistent rain interspersed by brighter and showery intervals with a tendancy for rather colder westerly winds of polar origins as we head towards christmas week..it's a good trend towards cold incursions from the northwest as time goes on, IMO it's much better than boring mild stagnation nothingness.

[shedhead]

I think it was more to do with the fact people were saying we'd be locked into a pattern of H Pressure limpeting over C europe for 2-3 weeks and some even saying  5 weeks+.

 

It was pretty clear a mild spell of weather was incoming when the models were being consistent in showing so for this week. The fact there are differences in outputs as close as later on this weekend is proof really that no matter what solutions are being shown from the outputs (be it mild or cold)...it is simply unreliable to look that far ahead. A couple of days ago the runs were showing a limpeting high pressure right from start to finish!

 

I'm not saying it is now suddenly showing cold weather coming to our shores, but there does seem to be even more emphasis now of a change in weather as we head into next week - perhaps to a more unsettled 'tad cooler' phase.

There is still nothing to suggest HP will not be 'limpeted' over Europe for several weeks to come Chris.  Yes is might slip a bit farther south at times, but despite the 'possibility' of some cooler phases if it does so the general pattern of Euro High, deep PV and a overall Atlantic flow that's on the mild side has not changed.

Edited December 10, 2013 by shedhead

[No Balls Like Snow Balls]

I think it was more to do with the fact people were saying we'd be locked into a pattern of H Pressure limpeting over C europe for 2-3 weeks and some even saying  5 weeks+.

 

It was pretty clear a mild spell of weather was incoming when the models were being consistent in showing so for this week. The fact there are differences in outputs as close as later on this weekend is proof really that no matter what solutions are being shown from the outputs (be it mild or cold)...it is simply unreliable to look that far ahead. A couple of days ago the runs were showing a limpeting high pressure right from start to finish!

 

I'm not saying it is now suddenly showing cold weather coming to our shores, but there does seem to be even more emphasis now of a change in weather as we head into next week - perhaps to a more unsettled 'tad cooler' phase.

 

Has there ever been in the climate history of the UK a weather pattern that has been locked in for months on end like some posts always suggest is going to happen?, is it even possible? the answer to the latter is almost probably no. As we all know the weather and climate is very fluid and dynamic so for posts to mention locked in scenarios for months and months is imo way way pie in the sky.

[carinthian]

After seeing the ECM operational run I was hoping to see a better set of ECM ensembles so that's disappointing. The rest of the 00hrs outputs are underwhelming from a cold perspective. My horror rating was threatening to go upto 9.5/10, however the ECM operational and GFS06hrs trend in its lower resolution have shaved that down to 8/10!

 

The more positive ECM output still remains marooned at T216 and 240hrs and we'll see this evening whether this moves a little closer. Regardless of the ensembles troughing digging further south over the UK does correlate with pressure building to the east and ne.

 

The first step out of this zonal mild is to at least get that to verify,then upstream its key that theres more amplification to help carve a bit more sharpness to that trough. As I said last night a more festive feeling Xmas is reliant on the ECM calling the trend correctly, that really is now our only hope!!!

From our part of Europe, no snow in the short term. Having spoken to our forecast advisors for the important Christmas Period, the feeling here is that they expect to see the high pressure zone move north and east during this period and allowing moisture into the Alpine regions with a lowering of the Atlantic jet into Southern Britain and Western Europe. So we may eventually see some snow at altitude. Read what you will into this for Britains post 10 day outlook. But confidence in our portal forecasts is high as 60 % for a change in type.

 C

[nick sussex]

I wonder if the slowing of the zonal winds at around 60 to 70 north is aiding that Siberian high?

 

 

PS Thanks Carinthian for that info, that would be great news if it verifies, its been a strange last few weeks here, lots of snow end of November and absolutely brilliant early season skiing under cloudless skies, Compared to recent years where the snow has come later its been a wonderful start but that limpet high needs to take a hike otherwise the resorts are going to have problems with this relentless sunshine and rising freezing levels.

Edited December 10, 2013 by nick sussex

[steelermark]

Here is the 11.50 ob from Glasgow MPG, showing temp of 14c, with a max of 15c looking very possible... prob best not to rely to heavily on GFS predicted temps, whether they be max or min.

 

. EGPF 101150Z 21014KT 9999 FEW021 BKN038 14/08 Q1021

 

Don't post very often, normally just read but where have you got 14c maybe up to 15c from? According to the met office the maximum temperature at Glasgow airport was at 1pm today at 12.4c. At 2pm it was 11.8c, so clearly slowly falling away. It's certainly not 14c or 15c. yes it's mild but why exaggerate to make your point?

 

It's 2c cooler in Chesterfield today than it was yesterday at 1pm, same in Nottingham, Sheffield, City of London etc.

 

Yes it's mild and will stay mild for the reliable, I think we're all aware of that by now. We certainly don't need reminding every other post.

[No Balls Like Snow Balls]

Don't post very often, normally just read but where have you got 14c maybe up to 15c from? According to the met office the maximum temperature at Glasgow airport was at 1pm today at 12.4c. At 2pm it was 11.8c, so clearly slowly falling away. It's certainly not 14c or 15c. yes it's mild but why exaggerate to make your point?

 

It's 2c cooler in Chesterfield today than it was yesterday at 1pm, same in Nottingham, Sheffield, City of London etc.

 

Yes it's mild and will stay mild for the reliable, I think we're all aware of that by now. We certainly don't need reminding every other post.

 

I did notice this myself but didn't want to rock the boat so to speak lol.

[Summer Sun]

Yesterday the NAO showed a 50 / 50 split today its now going slightly positive before a possible drop towards Jan

 

[legritter]

Well certainly something more Mobile looking at current charts and i,m eagerly awaiting tonights runs ,GFS as it looks way out into the dark realms of well past 10 days i only use for trend setting keeping an eye on synoptic set ups that reapear closer to the more reliable .but i feel we are on a change with some interesting weather being modeled for  next week .When i first got into computers about 5 yrs ago i couldnt believe my luck in finding Net weather and all these charts,.as back in the 70s and 80s i used to get charts from local weather centre 5days per week .little did i realise that although it fuelled my hobby [obsession ]it can at times be frustrating when all you want is snow every winter ,which in our position on the globe wont happen every year .so it looks like some interesting developements could be taking place over n /west Russia area and of course north Atlantic ,and the winter as only begun ,Brilliant Forum and thanks to regular posters who go that extra Mile giving us technical info ,cheers .

[carinthian]

I wonder if the slowing of the zonal winds at around 60 to 70 north is aiding that Siberian high?

 

ecmwfzm_u_f240.gif

 

PS Thanks Carinthian for that info, that would be great news if it verifies, its been a strange last few weeks here, lots of snow end of November and absolutely brilliant early season skiing under cloudless skies, Compared to recent years where the snow has come later its been a wonderful start but that limpet high needs to take a hike otherwise the resorts are going to have problems with this relentless sunshine and rising freezing levels.

 

Same here Nick. Plenty of snow on the ground but mountain weather now turning fairly mild under a cloudless sky and high pressure centre bang over us now at 1037mb. No snow forecast here until at least 18th December , but cheered about the prospect of a change taking place this time next week.

 C

[johnholmes]

I personally totally agree with you but many on here like the search for cold, no matter how far out, which model it is, or how unlikely it is. I am sure by now you know which posters will post the dull, boring but objective view of the various outputs at the various time scales?

 

Asking for discussion of the models without sniping at someone else instead of hitting the report button is a bit like wanting heavy snow tomorrow-it just does not happen. Can we have some objective commenting on the 12z outputs from the models please-just for a change?

[Chris K]

There is still nothing to suggest HP will not be 'limpeted' over Europe for several weeks to come Chris.  Yes is might slip a bit farther south at times, but despite the 'possibility' of some cooler phases if it does so the general pattern of Euro High, deep PV and a overall Atlantic flow that's on the mild side has not changed.

 

True, however I still stand by the fact that posters don't say it in a way like you have just now. It is all down to interpretation and too often people write that a pattern may persist for weeks on end without stating the fact phases of different weather will occur inbetween.

 

 

Has there ever been in the climate history of the UK a weather pattern that has been locked in for months on end like some posts always suggest is going to happen?, is it even possible? the answer to the latter is almost probably no. As we all know the weather and climate is very fluid and dynamic so for posts to mention locked in scenarios for months and months is imo way way pie in the sky.

 

Exactly that was my point....but without making it sound like I'm calling people dumb...similar to my response to shed above - people can mis-interpret this fact and go by these posts that say we are on course for so called 'locked in scenarios'. All down to each person I guess.

[Paul]

Don't post very often, normally just read but where have you got 14c maybe up to 15c from? According to the met office the maximum temperature at Glasgow airport was at 1pm today at 12.4c. At 2pm it was 11.8c, so clearly slowly falling away. It's certainly not 14c or 15c. yes it's mild but why exaggerate to make your point?

 

It's 2c cooler in Chesterfield today than it was yesterday at 1pm, same in Nottingham, Sheffield, City of London etc.

 

Yes it's mild and will stay mild for the reliable, I think we're all aware of that by now. We certainly don't need reminding every other post.

 

Actually this isn't correct - the metar report from Glasgow airport was showing 14c at both 11:00 and 12:00 today.

 

But anyway, can we use this thread to discuss the models please. 

[snow freak]

Has there ever been in the climate history of the UK a weather pattern that has been locked in for months on end like some posts always suggest is going to happen?, is it even possible? the answer to the latter is almost probably no. As we all know the weather and climate is very fluid and dynamic so for posts to mention locked in scenarios for months and months is imo way way pie in the sky.

yes there has.  winters of 1948/9 and 1962/3 not forgetting the 'little ice age' between the 1600's and 1800's.  so it is possible to having locking patterns even in the UK.

[Gael_Force]

Don't post very often, normally just read but where have you got 14c maybe up to 15c from? According to the met office the maximum temperature at Glasgow airport was at 1pm today at 12.4c. At 2pm it was 11.8c, so clearly slowly falling away. It's certainly not 14c or 15c. yes it's mild but why exaggerate to make your point?

 

It's 2c cooler in Chesterfield today than it was yesterday at 1pm, same in Nottingham, Sheffield, City of London etc.

 

Yes it's mild and will stay mild for the reliable, I think we're all aware of that by now. We certainly don't need reminding every other post.

 

The figures quoted are from the airport metar  - NOAA site link.  just change ICAO code for your local obs.

 

http://weather.noaa.gov/weather/current/EGPF.html

 

This link gives some details for anyone unfamiliar with all the abbreviations.

 

http://en.wikipedia.org/wiki/METAR

Edited December 10, 2013 by Gael_Force