Model output discussion - 20th Feb onwards

[phil nw.]

The London ens graph showing quite depressed temperatures into the second half of March

as much a reflection of the cold east wind off the N.Sea as anything else.This has now set in and looks like being a feature for the next few days.

Beyond that some differences in the operational runs wrt movement of the high but the general trend seems to shift it west/south west into the Atlantic.

A change of emphasis to come then with something from the west or north west by the looks-maybe a brief northerly if the ECM op verifies but the means certainly favour a move towards a more changeable pattern next week.

[Singularity]

Excellent post as usual by Tamara I was not aware that the seasonal changes kicked in so rapidly. Bang goes my theory about the longer lived MJO encouraging less westerly momentum in the ECM runs! Perhaps it is purely down to how the lower stratosphere is being handled by that model, the vortex split happening to align more favourably.

Or maybe I have the wrong impression - the April composite for a strong MJO in the Central Pacific ( phase 8 ) - i.e. constructively interfering with an El Nino state - depicts a cold pattern for the UK with high latitude blocking to the NW, and is actually the best high latitude blocking pattern out of all the phases. La Nina-like tropical activity produces a lot of mid-latitude blocking. To be honest I'm not sure how this ties in with Tamara's post at all?  Thanks in advance for clarification on the matter 

 

In any case - thinking about recent GFS output in light of what she has said, the model is decreasing MJO amplitude pretty quick in phase 5 starting about a week from now, yet it does not show AAM decreasing much at all, even with the negative bias it is known to have... so perhaps it is responding effectively to the continued Nino atmospheric state in the Pacific?

 

I have been given a lot of thinking to do!

For now, to give an idea as to what influence the MJO might have if it doesn't lose amplitude as readily as the models are currently suggesting, here's what phases 6 and 7 (western Pacific) of the MJO correspond to in March, along with phase 7 for April in case the MJO wanders about a bit before getting that far - assuming it even does.

  

That can be summarised as a generally drying-out influence with easterlies well supported for the final week of March. Given the indications that a trough will be dropping south through Scandinavia just ahead of that period, this is a development worth looking out for IMO. The resulting temperatures are guesswork; you could get a chilly draw from NE of the UK, or something warmer from the eastern Mediterranean. Interestingly the MJO forcing may also help to sustain a split trop. vortex.

[fergieweather]

28 minutes ago, Singularity said:

That can be summarised as a generally drying-out influence with easterlies well supported for the final week of March. Given the indications that a trough will be dropping south through Scandinavia just ahead of that period, this is a development worth looking out for IMO. The resulting temperatures are guesswork; you could get a chilly draw from NE of the UK, or something warmer from the eastern Mediterranean. Interestingly the MJO forcing may also help to sustain a split trop. vortex.

The latest EC Monthly calls for +ve MSLP anomalies building across Scandinavia post-easter period, followed by same into early-mid April in the Arctic. There's some GloSea5 support for this. UKMO thus consider most probable current outcome is for temperatures a bit below average late March and through early April, with likelihood of N-NE flow and continued risk of frosts for some time. 

[jethro]

2 minutes ago, Greenland1080 said:

I love nagging East'NE winds well into spring giving frosts, cold biting winds.....Well into late Spring....The models suggest this and possible flurries next week...my kind of weather that.

Early spring warmth isn't my cup of tea at all...produces bugs an wasp growth.

And I'm the exact opposite, cold, biting winds with frost spell disaster for Magnolias  If you're still around Fergie...when you say temps a bit below average, any idea just how much below?

[Essex snowman]

Hopefully well below average be lovely cold wind with possible wintry showers il fetch me hot water bottle 

[Milhouse]

35 minutes ago, Greenland1080 said:

I love nagging East'NE winds well into spring giving frosts, cold biting winds.....Well into late Spring....The models suggest this and possible flurries next week...my kind of weather that.

Early spring warmth isn't my cup of tea at all...produces bugs an wasp growth.

Which models?

Looks fairly settled and mild here

The ECM 0z however looked much colder but the outcome for next week is far from confirmed.

Edited March 15, 2016 by Milhouse

[I remember Atlantic 252]

8 minutes ago, Milhouse said:

Which models?

Looks fairly settled and mild here

The ECM 0z however looked much colder but the outcome for next week is far from confirmed.

don't think ECM looks as vile now? 

[Guest]

MY LATEST REPORT UPDATED WITH MARCH 15TH 2016 INPUT

Please note that most of the charts that I refer to in this post are through “live” links which update periodically. So, if you are reading this a few hours after publication, the charts may already have updated. My comments relate to what the charts showed at the time of this posting.

Will We See Any Signs of the Stratospheric Warming reaching the Surface?

What an excellent and very timely post today from Tamara. It does seem increasingly unlikely that we will get any significant or prolonged  “unseasonal” cold even if the strong stratospheric reversal does reach the surface sooner rather than later. The MJO, that I have been following as part of these reports, is in the wrong phases to assist with any HLB in our part of the Arctic and it looks like it will be at least another fortnight until it reaches the important phases, 7, 8 and 1 again.

It seems unclear to the experts why the almost record strength stratospheric reversal has not filtered down through the troposphere and down to the surface properly. Tamara’s analysis appears as close as anyone’s to explaining it all. It is well beyond my limited understanding. There seem to be just too many variables involved. The complex relationship of the mature El Nino and how its forcing prevents or assists stratospheric warming events is just one factor. The fact that we are now well into Spring, with ever increasing solar energy, would lead to a very different SSW surface impact compared to a mid-Winter event.

I am not sure if I have been chasing shadows! There could still be some surface impacts and pattern changes but probably not on a scale to have more than temporary influences. I will still be looking for synoptic patterns that seem unusual even for the changeable Spring season. I will not completely call off the chase just yet but I intend to wind down the frequency of my reports and the length of them. If there is strong demand from the readers of my posts to keep it going a while longer I may be persuaded.

Before I get into the detail of today’s report, I feel that I should make a general comment. I accept that those reading and/or posting on this thread will come from a multitude of backgrounds with a whole range of experience from the specialists and professionals, to the amateurs, the general enthusiasts through to the beginners just starting to learn about this wonderful subject. We see a great variety of posts and opinions and some healthy exchanges. I always have full respect for others’ opinions and would never wish to criticise a fellow poster. If someone disagrees with another’s views or factual input, a constructive response is always appreciated. Last night there were a number of quite unwarranted and unreasonable comments. A number of posters, including myself, drew attention to some eye catching “cold” charts late in the 12z ECM run. Almost everyone of these posts were criticised and in some cases the poster was insulted (I wasn’t – or if I was, I am probably too thick skinned to be aware of it). Hardly any of the criticisms were backed up with any facts and it left a thoroughly unpleasant taste in my mouth and I’m sure many of the readers. The moderators removed some of the worst ones but not all of them. Whatever experience any of us have, we are “all” learning. So, let’s keep this a friendly and welcoming place with pleasant and constructive comments

The Models Today:

Unless I see any stronger signs that a model or a particular run might be indicating a broader pattern change, I propose to greatly abbreviate this part of my report. I am dropping the T+144 chart comparisons that I started a few days ago. Gibby does an excellent job of model assessment in his daily reports and I would not wish to duplicate any of his sterling work. This morning he mentioned a slightly colder (not a raging northerly) 2 week outlook indicated by several models or some ensemble clusters within them. He also mentioned that the ECM 0z run, although still the coldest of all the models, had downgraded slightly on yesterday’s 12z run which caused so much interest (and controversy).

After a quick glance through the 12z runs, most of the models do look slightly colder than the 0z runs. There is a scattering of (mostly Arctic) cold shots shown at slightly differing times. Some are around T+144 to T+168 and another around T+216 (a follow on from yesterday’s T240). Yet again, the ECM shows the most consistently cold run (the 12z run has just finished coming out). On their T240 they do move the main cold flow a little further into Europe and back the flow slightly over the UK. Now, over to the regular “coldies” to show and assess these.

AO Ensemble Charts: 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao_index_ensm.shtml

A much more mixed and very uncertain outlook with half the ensemble members ending positive and half negative by March 25th.The NOAA forecast for some HLB or no HLB is “up in the air” at the moment.

MJO Ensemble charts:

I am considering handing the whole MJO analysis back to Singularity who always does an excellent job and has far greater knowledge and experience than I do. I shall post today’s ensemble charts and make much briefer comments below these. Here are today's MJO ensemble charts for the big 4 and Kyle MacRitchie’s for March 15th. 

UKMO:  http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ukme.shtml

ECM:  http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ecmm.shtml

NCEP/GEFS:  http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/ncpe.shtml

JMA:  http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/jman.shtml

Kyle MacRitchie:  http://www.kylemacritchie.com/real-time-maps/realtime-mjo/

UKMO: Their main change is rather greater amplitude through phase 5.

ECM:  They also have slightly increased amplitude and progress all the way to phase 7 by March 27th/28th.

NCEP/GEFS:  Little change.

JMA:  Very little change.

Kyle MacRitchie:  Continues his consistently bullish approach. He shows the MJO progressing through all the phases from 1 right through to 7 by April 5th and on to phase 8 by April 10th.

UKMO (only up to 10 days) and ECM are gradually coming into line with Kyle MacRitchie!

Singularity felt that I should continue with Kyle’s analysis what do other experts like Tamara feel about the validity of Kyle’s research?

Current Surface Arctic Temperatures:

Whilst I am still producing these reports, I shall keep most of this section intact. Even without any prolonged cold, we are still very likely to get at least several cold shots sourced from around this region.  If the source is very cold, the uppers below -8c and the airstream direct enough, we could still get something wintry. Our part of the Arctic is currently considerably colder than it has been almost all Winter.

GFS – Northern Hemisphere Current Temperatures:

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=6&code=0&mode=9&carte=1

The link to this chart updates 6 hourly with each GFS run. At the time of writing it is showing a chart for 1900 today (15th March***). As this is T0 to T6 hours, it should be pretty accurate. 

In the Arctic, temperatures close to the North Pole are around -20c to -28c (as yesterday). In “our” part of the high Arctic (around the Barents Sea) temperatures are lower at around .12c to -20c (-8c  to -16c yesterday). Most of Scandinavia has warmed up to around 0c to +4c today (0c to -4c yesterday). Much of northern Siberia is slightly less cold at around -28c to -36c with a smaller area below -40c today (-32c to -40c yesterday). The cold north/south wedge that developed through western Russia during the last 2 days is now around -16c to -24c ( -20c to -28c yesterday) with north-east Europe now 0c to -8c (-8c  to -12c yesterday).

So, overall a little less cold than yesterday except in the high Arctic around the Barents Sea.

*** Please note:   At the time of posting this link it was showing 1900 on Monday, March 15th. The charts are automatically updated 4 times a day, so the temperatures shown will be different to those I just mentioned above. We can follow the trends by looking at the latest data at any time from now on. It is vital to note the time of day to take account of daytime/nighttime variations. So for like for like comparisons, for example the 1900 charts for each day should be available to view from the 12z (T+6) updates which are published around 1600 or about 4 hours later. This also applies to some of the other charts I link to in this post.

Svalbard Daily “Maximum” Temperature Forecast for 10 Days:

Here are the links to the 3 Svalbard stations that I am monitoring.

Central Svalbard – Longyearbyen 28 m asl:   

http://www.yr.no/place/Norway/Svalbard/Longyearbyen/forecast.pdf

March 18th  -13c;   March 21st  -12c;    March 24th  -9c.

West Svalbard – Ny-Alesund:                                                            

http://www.yr.no/place/Norway/Svalbard/Ny-%C3%85lesund/forecast.pdf

March 18th  -14c;   March 21st  -14c;    March 24th  -12c.

South Svalbard – Sveagruva:                                          

http://www.yr.no/place/Norway/Svalbard/Sveagruva/forecast.pdf

March 18th  -17c;   March 21st  -19c;    March 24th  -16c.

The general trend is for the “maximum” temperatures (which fell from much higher levels over last few weeks when they often exceeded 0c), to bottom out over this weekend and then only rise very slightly into next week but still maintain low levels.

These links will update automatically at frequent intervals throughout the day. They are the Norway met office’s predictions. We need to be aware that these are only a forecast that is subject to change and I am told that the Arctic surface temperature forecasts are not completely reliable even at short range. 

To put the above figures into context, here is a link to the main Longyearbyen site:  

http://www.yr.no/place/Norway/Svalbard/Longyearbyen/statistics.html

This shows monthly means, and actual highest/lowest temperatures recorded during this winter and goes back further. Apart from a couple of days in December, Svalbard is now seeing “maximum” temperatures falling to well below average, for the first time since Winter 2014/15

Final Comment:

So, most of my indicators are showing a slight warm up today.

 

Edited March 15, 2016 by Guest
Check links all working; ECM 12z comment; grammar & spelling

[shotski]

24 minutes ago, Greenland1080 said:

ECM I suspect may start to show Easter cold fare...I love cold Easter markets

Yep, the outlook as far as I can see is for a rather raw feel to the weather with very little in the way of spring warmth for the next few days at least. Credit to the met office again who called it spot on when a lot of people were ramping positive temperature anomaly charts at t360.  

Edited March 15, 2016 by shotski

[Milhouse]

15 minutes ago, Greenland1080 said:

ECM I suspect may start to show Easter cold fare...I love cold Easter markets

 

Looks to me like its fallen more in like with the rest of the model suite?

[I remember Atlantic 252]

2 minutes ago, Milhouse said:

Looks to me like its fallen more in like with the rest of the model suite?

was still on 00Z for your quoted post

[Nick L]

The northerly on the 00z EC has been firmly shunted east on the 12z to a much more transitory affair. Wouldn't be at all surprised now if it is off the table completely by tomorrow, with high pressure remaining dominant.

[Milhouse]

Temporary northerly at T+216, 240 on the ECM 12Z

http://www.wetterzentrale.de/pics/Recm2161.html

 

[Summer Sun]

The high is putting up more of a fight on this run from ECM a temporary northerly is possible but far from certain

After such a wet winter I wouldn't be a bit surprised if we enter a lengthy period of below average rainfall

[Summer Sun]

6 minutes ago, Greenland1080 said:

 

How can 216 240 be temp....we can't see any further?

Its quite clear from ECM that the northerly flow starts to get cut off as the high edges eastwards anyone hoping for a freeze and snow for Easter could be in for some disappointment yes the odd day of something colder from the north is possible but I can't see anything lasting more than a day or 2 at this time

[ANYWEATHER]

Hi Folks.... There is no point in getting hung up on detail , the high gets shunted west from both ecm and gfs at the later time frame . The outlook remains cold ,compared to average....Synoptics  on detail will change in the days ahead but the overall cold theme remains..a very slow start to Spring   

[IDO]

10 minutes ago, ANYWEATHER said:

Hi Folks.... There is no point in getting hung up on detail , the high gets shunted west from both ecm and gfs at the later time frame . The outlook remains cold ,compared to average....Synoptics  on detail will change in the days ahead but the overall cold theme remains..a very slow start to Spring   

Hi. What cold? The CET for March is -0.4c below average, NW Scotland had 16c max today and the minimum max was over 6c! This is typical March weather, with cooler and warmer interludes. Even the Met update makes no mention of cold, more average but feeling warm in the sun. A cold spell would be 3-4c below average for an extended period. This is run of the mill stuff IMO. 

I note that as expected ECM have downgraded heights as usual and have now moved towards GFS and its own mean with a day or so of fleeting cold rather than its usual D10 stuff. Though GEM and GFS are moving away from even that so give it a few more runs and that "northerly" might vanish. HP looks like the call as the omnipresent Azores High continues to dominate the pattern. 

[feb1991blizzard]

1 hour ago, Greenland1080 said:

ECM I suspect may start to show Easter cold fare...I love cold Easter markets

 

 

Do they actually offer Easter markets?, I have never seen any, could you please tell me what bookmakers they are on.

[shotski]

54 minutes ago, IDO said:

Hi. What cold? The CET for March is -0.4c below average, NW Scotland had 16c max today and the minimum max was over 6c! This is typical March weather, with cooler and warmer interludes. Even the Met update makes no mention of cold, more average but feeling warm in the sun. A cold spell would be 3-4c below average for an extended period. This is run of the mill stuff IMO. 

I note that as expected ECM have downgraded heights as usual and have now moved towards GFS and its own mean with a day or so of fleeting cold rather than its usual D10 stuff. Though GEM and GFS are moving away from even that so give it a few more runs and that "northerly" might vanish. HP looks like the call as the omnipresent Azores High continues to dominate the pattern. 

Not true, they do mention colder than average.  

[Cloud 10]

Signs of Greenland ridging on todays 8-14 dayer from NOAA.?

 

[Allseasons-Si]

I am surprised that no one has commented on the ukmo at 144hrs

would love to see the 168 hrs,prob with a strait northerly,we shall see on the 00z in the morning.

[Captain Shortwave]

The models do point to the high near the UK moving westwards somewhat allowing winds to gradually swing from the east/north east to a more north to north west direction.

ECM ens

      

There will be some fronts running down the eastern flank of the high which would bring thicker cloud and a few spots of rain at times, the good news is that behind these fronts we should hopefully see some brighter skies develop, especially for those in the firing line of the north sea low cloud train at the present time. There is a chance of some colder weather developing, but it will have to take some deep cold and some very low heights to generate the kind of situation that most coldies would want. For me it would be nice to see the sunshine return

As an aside some posts have been moved to the moans/banter thread. Can we stick to model discussion please in here. Thanks

 

[Allseasons-Si]

The 18z gfs at 144hrs has a neg tilted trough in the atlantic with better height's up into iceland/greenland,after that?,maybe watch for a shortwave from the NE,could be wrong.

[MP-R]

28 minutes ago, Captain Shortwave said:

The models do point to the high near the UK moving westwards somewhat allowing winds to gradually swing from the east/north east to a more north to north west direction.

ECM ens

      

There will be some fronts running down the eastern flank of the high which would bring thicker cloud and a few spots of rain at times, the good news is that behind these fronts we should hopefully see some brighter skies develop, especially for those in the firing line of the north sea low cloud train at the present time. There is a chance of some colder weather developing, but it will have to take some deep cold and some very low heights to generate the kind of situation that most coldies would want. For me it would be nice to see the sunshine return

As an aside some posts have been moved to the moans/banter thread. Can we stick to model discussion please in here. Thanks

 

Could do with that high buzzing off so we can get something like this:

With attendant weather like this:

Everything with this chart needs to move a couple of hundred miles west:

One can hope!

[feb1991blizzard]

Big undercutter coming up here.

 

Heavy frontal snow for the North at 276.

Edited March 15, 2016 by feb1991blizzard