Model output discussion - 20th Feb onwards

[Frosty.]

33 minutes ago, phil nw. said:

Yes quite a bit of support for something of a warm up karl

Let's hope so Phil, some recent runs have shown similar outcomes for mid March bringing pleasantly warm and settled conditions it would make a nice change to see high pressure in the ascendancy after months of seemingly endless Atlantic depressions with barely any respite!

[I remember Atlantic 252]

2 minutes ago, Frosty. said:

Let's hope so Phil, some recent runs have shown similar outcomes for mid March bringing pleasantly warm and settled conditions it would make a nice change to see high pressure in the ascendancy after months of seemingly endless Atlantic depressions with barely any respite!

that's the spirit Frosty.! keep checking models, hoping it's still there

[Frosty.]

1 minute ago, I remember Atlantic 252 said:

that's the spirit Frosty.! keep checking models, hoping it's still there

Cheers, yes I really hope the Gfs 6z is right about week 2..warm and sunny would be a welcome change indeed!

[I remember Atlantic 252]

Just now, Frosty. said:

Cheers, yes I really hope the Gfs 6z is right about week 2..warm and sunny would be a welcome change indeed!

certainly would, I either want a dry/warm March, or a March 2013, But as models flirting with good warm up then bring it on!
 

[Banbury]

1 hour ago, mushymanrob said:

 

guys, this is the model discussion thread, as the models dont go out to easter yet, arent predictions of what easter might hold be speculative? even ramping?

i have no idea what weather we will get in 3 weeks time, (my bad, not the 4 i mentioned earlier) im not expecting it to become mild and stay mild, spring is a season of mixed fortunes so after the likely warming up abit next weekend, im sure itll go colder again at some point. it might get cold enough for snow, but those events arent as likely as cold dry overcast easterlies - and thats assuming we even get an easterly.

by next weekend the anomaly charts will start to bring easter into their view, if, between now and then they start to suggest a large pressure rise over scandinavia - ill believe it. if they dont, i wont.

Sorry to go on - if thats the case why is it ok for you to say it wont snow, lets be fair Mush

[mushymanrob]

ok broken record time.... but ill say it anyway! lol

dont expect a change, the noaa's have been consistent, that ridge to our near southwest WILL happen by next weekend, thats pretty certain now. how long it lasts, how mild/pleasant itll get is unknown at this date but theres plenty of room for optimism IF its springlike warmth you desire.

[mushymanrob]

5 minutes ago, Banbury said:

Sorry to go on - if thats the case why is it ok for you to say it wont snow, lets be fair Mush

i didnt say it  wont snow!

i said "i doubt it" which 3 weeks out with no model data to go on is fair enough isnt it?

Edited March 5, 2016 by mushymanrob

[Banbury]

Options of much chillier weather

So many blocked set ups on the cards , be interesting viewing adter mid month

Edited March 5, 2016 by Banbury

[feb1991blizzard]

1 hour ago, phil nw. said:

Yes quite a bit of support for something of a warm up around mid-month Karl.

And for a coldening at the end, not least from the stratosphere.

[Daniel*]

UK on the fringes as per, mid month onwards does look interesting unbelievably it is not time for "hibernators" to call it a day yet. If we could tap into that we would be laughing even this late on, I do not think cold conditions will be for everyone as in all likelihood there would be an abundance of cold rain/sleet down south it does not really bother me. But interesting to see how this pans out could end up with a very chilly Spring stretching to April and beyond? With what the strat is getting up to, Eurasia may be being fooled into winter mode when at a time the landmass is supposed to be breaking out of it. 

[phil nw.]

28 minutes ago, feb1991blizzard said:

And for a coldening at the end, not least from the stratosphere.

Yes did notice the latest gefs at the end of the run-possible Scandi.trough? 

Depends on the orientation of course-the deepest cold that would still be around could still miss us and go into C./E. Europe with us on the edge of things.

Too soon to speculate yet on that for me i would rather wait for consistency in a couple more ens. runs for that one that's why i did't offer any comment in my earlier post.

 

Edited March 5, 2016 by phil nw.

[bobbydog]

34 minutes ago, feb1991blizzard said:

And for a coldening at the end, not least from the stratosphere.

a "coldening"? is that more severe than a cooling?.......

[Banbury]

37 minutes ago, Daniel* said:

UK on the fringes as per, mid month onwards does look interesting unbelievably it is not time for "hibernators" to call it a day yet. If we could tap into that we would be laughing even this late on, I do not think cold conditions will be for everyone as in all likelihood there would be an abundance of cold rain/sleet down south it does not really bother me. But interesting to see how this pans out could end up with a very chilly Spring stretching to April and beyond? With what the strat is getting up to, Eurasia may be being fooled into winter mode when at a time the landmass is supposed to be breaking out of it. 

Indeed Daniel some decent cold sat waiting....................if only

Edited March 5, 2016 by Banbury

[Guest]

MJO Ensemble charts:

Here are todays MJO ensemble charts for the big 3 and Kyle MacRitchie for March 5th.   UKMO, ECM and GEFS have all reduced the amplitude. Kyle MacRitchie has yet again retained his much more bullish outlook with it staying in phase 8 for longer and on into phase 1 at good amplitude.

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

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

Singularity stated yesterday that I should continue to post Kyle’s charts after I had asked him for his opinion. Kyle modifies his ensemble charts (from CFS) and makes allowances for ENSO, tropical wave interference and other factors. I found a little more information on Kyle and his methodology. As this is important for deciding on how much attention we should pay to his predictions I show this below. This is copied from different parts of his website and from links from that.

Kyle MacRitchie Resume:

http://www.kylemacritchie.com/macritchie_resume.pdf

Realtime Multivariate MJO Index (RMM Index):

(direct quote): ...."The RMM index was created by Matt Wheeler and Harry Hendon (Bureau of Meteorology, Australia) in a paper from 2004. They use EOF analysis to track the MJO on a simple circular diagram. This is a popular method of tracking the MJO because it is easy to visualize and simple to make. However, since we do not know what the MJO actually is, we need to be careful to interpret the RMM index simply as a convenient method of tracking the MJO. It does not necessarily represent the true structure of the MJO, and often it is confused by other equatorial waves.

The RMM index is created like this:

·         Start with OLR and zonal wind anomalies at 850 mb and 200 mb averaged over the Equator from 15S-15N.

·         Subtract the linear relationship that these fields have with ENSO.

·         Perform an EOF analysis of all three fields, combined.

·         The first and second EOFs are orthogonal to each other and show a propagating pattern, as described above.

·         Plot the principal components (RMMs) associated with the first two EOFs on a polar coordinate plot.

·         Arbitrarily split the circle into 8 phases. There is nothing magical about 8 phases. It could be as many, or as few, phases as you’d like.

·         The amplitude of the MJO is shown by the distance of the plot from the center of the circle. This is equivalent to the modulus of the PCs [that is: amplitude = sqrt(PC1.^2+PC2.^2)].

·         When the MJO amplitude is greater than 1 (outside the smaller circle), we consider the MJO to be active. When it is less than 1 we consider it to be inactive. Again, the number 1 is completely arbitrary.

MAP Help – MJO:

This is modeled after the Wheeler and Hendon (2004) RMM phase space and is most similar to a similar approach that I’ve written about in MacRitchie and Roundy (2012). This approach uses the CFS MJO projections, as used in other figures on this website, to track the MJO. This results in a smoother signal than the WH04 index with less interference from other modes"..... (end of quote).

Abbreviations Used:

To assist those interested but not familar with some of the abbreviations used, I show these now.

CFS = Climate Forecast System;  WH04 = Wheeler and Hendon 2004 modified multivariant MJO index;  EOF = Empirical Orthogonal Function; OLR = Outgoing Longwave Radiation.

I realise that some of you will be like me - confused! I wanted to post these details just once as I will be interested in Singularity's (and others) further feedback on this to help authenticate or dismiss these modified MJO charts as being a useful comparison to those coming from the main models. Much of it is well beyond my modest expertise.

The state of the MJO may be highly significant during the next 2 weeks, especially while it interplays with the current SSW. It may well dictate if we are to see greater HLB and this is highly relevant to see if/when all the models pick up on this.

Edited March 5, 2016 by Guest
links did not all work - should now

[JoeShmoe]

Beer garden stuff next weekend and following few days from GFS12z, lovely - early spring warmth !

[Summer Sun]

Hello spring!

[pureasthedriven]

On 3 March 2016 at 2:28 PM, Nicholas B said:

 I don't suppose anyone would stick there neck out that far but....  

Ooh, no further questions your honour!

[jy]

On ‎01‎/‎03‎/‎2016 at 0:41 PM, Bristle boy said:

Agree totally Mushy.

We're talking early March average temps versus actual temps.

IMBY - I'd punt at 8/9c average. So colder than average 5/6c?

If daytime temps were going to get down, to say, 3/4c I'd be happy for someone to describe that as "Much colder than average"(for early March)

 

[Methuselah]

2 minutes ago, pureasthedriven said:

Ooh, no further questions your honour!

Objection, your Honour: it might squeeze out a snowflake or two before Spring arrives?

[Banbury]

Again after mid month we see another change to cooler weather

A short period of HP for the UK giving milder conditiond before a change to cooler /colder weather as we head towards Easter, falling Snow cannot be ruled out

 

[Banbury]

Undecided after 11th before cooler / colder weather returns in the run up to Easter

[Captain Shortwave]

Turning drier and milder by next weekend, this extending northwards with time according to the ECM

   

That day 9 chart is a cracker with widespread fine weather and the 12C isotherm approaching the south of the UK.

GFS and GEM solutions

   

Pretty good support for this solution, the JMA is cooler with the pattern a little further west.

[Milhouse]

Some great looking Spring charts have brought me out the woodwork for another year. Just like with widespread snow, a lot had to fall into place for such charts to verify but at the moment next weekend could be very nice. 

[mushymanrob]

i still think (unfortunately) the ecm and gfs current ops are too progressive with the eastward progress of the displaced azores ridge, (and consequently the warmest of the weather) as the noaa 500 mb charts currently suggest the displaced azores ridge is centered to the west of south. 

[Guest]

SOME POSSIBLE GOOD NEWS FOR COLDIES!!!

AO Ensemble Charts: 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

The AO ensemble charts have just been updated by NOAA as from today (March 5th). There is a very important and interesting development this evening. Earlier in the week the charts were showing the neutral AO starting to trend into the long predicted negative phase. Then over the last 2 days (up until yesterday) I posted charts with an increasing number of ensemble members taking it back into positive territory. If you look at the very end of today’s chart you’ll see that after peaking at round March 15th almost all the members move rapidly back through neutral into the negative phase by March 17th. It looks like they are trending down very sharply and I would expect (assuming the same signals are still being picked up) that they will go much lower in the following few days. I will certainly be following the daily updates very closely.

My Speculation:

I feel that this ties in with some of the model predictions for a temporary warm up (perhaps only lasting 2-3 days) at the end of next week and then a plunge back into something much colder. This would coincide with the peaking of the current SSW event and the fully split stratospheric vortex. If the likes of Judah Cohen are right we will see a complete coupling of the strat and trop vortices. The AO could well be in a very strong negative phase for several weeks. This is the significant HLB that a SSW might be expected to deliver. The main models generally downgraded their MJO expectations both with the brevity in phase 1 and in decreasing the amplitude. I would not be at all surprised to see the models starting to upgrade their charts again over the next few days and perhaps come into line with Kyle MacRitchie’s predictions (see my post made a few hours ago on that).

What I’ll Be Looking for in the Models for the Next Few Days and a Request for Several Updates:

I imagine that the main models that we all normally look at might be quite slow to pick up on any signals. Although perhaps the GFS is toying with the idea of the cold/warm/cold sequences on it's 6z and 12z runs. That is nothing unusual for the changeable Spring season but I expect quite dramatic and sudden swings.

Perhaps Fergie could confirm if the GloSea5 and EC-32 are showing signs of a more significant cooling off after mid-March following the milder blip (ie: a return to their “predominantly colder” outlook they were showing until very recently).  I would also be very interested to see if their own MJO predictive chart has changed again and is now hinting at a longer spell through phase 8 and into phase 1 at somewhat higher amplitude.

As the AO charts are from NOAA, I would imagine that their 8-14 day anomaly charts will start to show a trend towards more HLB during the next day or 2. I look forward to an update from John Holmes, Knocker or one of the regular posters of these charts together with their excellent analysis.

As usual, this is only my personal interpretation of what might fall into place and what I shall be looking out for. I still believe that this is an extremely exciting and uncertain period for all types of weather enthusiasts and especially model watchers. I would gladly give those wanting some warm dry weather a couple of Spring like days later next week but in exchange for a memorable cold spell lasting for a few weeks. Then we can put the long warm winter behind us. There will be plenty of time for warmer weather later in April onwards. While it is still just about possible to achieve a decent cold spell, join me in hoping for just that!

Looking ahead. I will post the latest AO and MJO ensembles later tomorrow and then Judah Cohen’s latest weekly AO report on Monday evening – this should be a really fascinating update. 

Edited March 7, 2016 by Guest