Model Output Discussion 1st January 2014-06z onwards.

[forecaster]

Aahhh the good old 'it's been like this for x amount of weeks so it'll carry on like this for eternity' forecasting method. Think I'll stick with the pros at the Metoffice, thanks. You never know, perhaps now Christmas is over, the vortex will stop making its 'presents' felt.

There is a little value in forecasting by persistence and the pros will use it to some extent. One measure of the quality of a forecast is whether it can beat both persistence and climatology. If both are better, the method tested obviously does not look too clever!

[Bristawl Si]

UK weather 2 to 3 weeks down the line?!

Well, i havent a clue! have you?

[kumquat]

UK weather 2 to 3 weeks down the line?!Well, i havent a clue! have you?

I think the clue now BB is in the deep low exiting the NE states and what it does as has been discussed and postulated by Nick S and Steve M coming into the 96 to 144 period. Not so far FI that we won't have an answer over the next 24 hr period. 

[bluearmy]

the extended ecm ens graphs are fairly revealing.  about a 50/50 split now on madrid being damp through week 2 and rome up to around 35% less settled.  the siberian express calling at warsaw and then berlin is gathering bookings in comparison with yesterday but looks no more than a 25% shot currently.  london does go cold through week 2 though scatter returns by days 14/15.  plenty of ice days in there compared to what we've become used to from the model.  as phil alludes above - are these proper easterlies with possible snowfall or just slack continental drifts (as the 00z op shows with an ice day day 10). thats two ecm suites on the same trend. really need naefs to come on board.  if ecm stays solid on this trend over the next three or four days and naefs refuses to join the party, the difference can only be ecm's better modelling of the upper strat.   as ever, plenty to be looking at.

[draztik]

All in all, a very confused picture has emerged. After a dogs dinner from this mornings ecm, its ext ensembles offer support for some form of block to our NE. This is in stark contrast to naefs, whch keeps lower heights over Scandinavia and the mean trough to our NW. The height anomalies covering days 10-15 (ecm), 11-16 (naefs) below

I had thought we'd be in a clearer state after the 0z output, but seemingly we will need a couple more runs before we can know if its more zonal ( tho less intensive than of late) or love from the east. Looking at all available data this morning, i favour the former. But must concede the ecm ens have thrown a spanner....

[mike Meehan]

After the ECM held an easterly party last night its the clean up today with bottles and debris lying all over the place!

 

Regardless of the morning climbdown by the operational run there is a trend for temperatures to fall looking at the De Bilt ensembles, the wind directions are all over the place.

 

http://www.weerplaza.nl/15daagseverwachting/?r=midden&type=eps_pluim

 

The robust signal for the continued rinse and repeat monsoon is now weakening but the outlook is messy if you're trying to pin some detail down. The PV still looks trouble some although not as strong, generally you can only work with so much given the PV location so there are things that you definitely know you wont see within the medium term, so Greenland block is out, northerly toppler out, upstream there is some uncertainty as to the depth and amplitude of troughing in the west/central USA as the pattern changes over there; which will therefore impact the amplitude of the jet coming out of the eastern USA.

 

In terms of whats to be expected over the UK well several options, troughing digging se with pressure still high to the ne, I'd still keep the possibility of an easterly within ten days, theres still a cluster of ECM solutions that bring this in.

 

Overall I think the zonal conditions that we've seen for weeks are on the way out, I think its look east or ne going forward, some trough disruption likely close to the UK and a possible battle ground scenario setting up before the PV finally edges sufficiently away.

 

With the easterly still refusing to disappear off the radar within the ten day period, just as the easterly disappeared quickly it could just as easily return, the margins remain very small either way.

It looks like Accu Weather are in agreement Nick, these are Jan '14 dates for Watford, however still a long way off and much can change.

 

 

 

 

12

 

Variable cloud, a shower

7° Lo -1°

Hist. Avg. 6° Lo 2°

 

 

13

 

Low cloud

4° Lo -1°

Hist. Avg. 6° Lo 2°

 

 

14

 

Decreasing cloud

2° Lo -3°

Hist. Avg. 6° Lo 2°

 

 

15

 

Sunny spells and patchy cloud

1° Lo -4°

Hist. Avg. 6° Lo 2°

 

 

16

 

Sunny periods

1° Lo -5°

Hist. Avg. 6° Lo 2°

 

 

17

 

Decreasing cloud and cold

0° Lo -4°

Hist. Avg. 6° Lo 2°

 

 

18

 

A shower in the afternoon

3° Lo 2°

 

Edited January 4, 2014 by mike Meehan

[shedhead]

Just looking at things overall.I think it 's reasonable to expect some easing of the Atlantic ferocity later next week as some heights look like developing over the continent.

This may build into a meaningful block later on and that maybe is what some of the Met office ens further out are showing.

A lot depends on where any block sits but it seems some sort of continental cold shows up in those colder ens members.

 

It's all very far way for now though and for the sake of clarity and being on topic we should continue to focus our discussions on the modeling we can view for ourselves for commenting on.

 

One other thing a few posts are getting grumpy again and having a dig at others,please stop this.

I would like a change as much as anyone but let's note what the current outputs show and avoid falling out with each other over it.

Probably not as much as me Phil, I'm now surrounded by water and it's starting to feel a bit like the Alamo around here...again!

 

It's at least encouraging to see some much colder air dropping into western Russia on the 06 GFS, with ridging extending well south of Svalbard, but agree there still does not looks to be an easy or guaranteed route to cold just yet.

 

Edited January 4, 2014 by shedhead

[bluearmy]

The 06z gefs more amplified in week 2 than recent suites. Better than consistent flat output! (And the NH profile much better as well)

Edited January 4, 2014 by bluearmy

[nick sussex]

 

It looks like Accu Weather are in agreement Nick, these are Jan '14 dates for Watford, however still a long way off and much can change.

 

 

 

 

12

 

Variable cloud, a shower

7° Lo -1°

Hist. Avg. 6° Lo 2°

 

 

13

 

Low cloud

4° Lo -1°

Hist. Avg. 6° Lo 2°

 

 

14

 

Decreasing cloud

2° Lo -3°

Hist. Avg. 6° Lo 2°

 

 

15

 

Sunny spells and patchy cloud

1° Lo -4°

Hist. Avg. 6° Lo 2°

 

 

16

 

Sunny periods

1° Lo -5°

Hist. Avg. 6° Lo 2°

 

 

17

 

Decreasing cloud and cold

0° Lo -4°

Hist. Avg. 6° Lo 2°

 

 

18

 

A shower in the afternoon

3° Lo 2°

 

I was hoping for something colder given the PV has dropped some very cold air into Russia! lol Yes still a way into the future, lets hope that the cards fall nicely.

 

The ECM actually has two chances for an easterly within 240hrs one like last night and another as that troughing digs south in the mid Atlantic, we don't get the required angle but a possibility.

 

 

That shortwave over the se would need to cut back and track sw, which would happen if the troughing in the mid Atlantic dug further south, that's effected by troughing over the central USA which effects the eastern USA amplitude which in turn effects the mid Atlantic jet, we need a steeper bounce north to the west of the UK.

 

Edited January 4, 2014 by nick sussex

[bluearmy]

I was hoping for something colder given the PV has dropped some very cold air into Russia! lol Yes still a way into the future, lets hope that the cards fall nicely. The ECM actually has two chances for an easterly within 240hrs one like last night and another as that troughing digs south in the mid Atlantic, we don't get the required angle but a possibility.

That's watford nick, not Warsaw!

[snowking]

It might be worth reposting this from yesterday - MJO phase 7 SLP Anomaly for January based upon wQBO and ENSO Neutral conditions:

 

 

Phase 7 is certainly where UKMO and GEFS were heading as of January 1st but we're still awaiting an update since then...

 

 

OLR plots certainly suggest things heading in this direction too towards the middle of this month:

 

 

So actually the UKMO/ECMWF op suggestions from yesterday (and indeed the extended ECM EPS today) should not come as a major surprise and perhaps offers an answer as to whether the ECMWF MJO projections have finally come around to the same thought as the UKMO/GEFS - that answer looks to be yes.

 

We of course have to bear in mind that all of these projections are NWP projections at 10-15 days+ away and so the usual caution should be applied, especially considering at the moment we only have one (perhaps two from Ian F's as ever very useful insight) ensemble suite showing something like this, but this all works hand in hand and so for as long as the MJO phase 7 projection is shown, NWP ensemble suites are likely to move towards a mean Scandinavian ridge solution - a solution which, it should be noted, also has lower stratospheric support to some degree.

 

It's difficult at this stage to tell whether this will become an end game or whether this will prove to be a temporary blip but with the minor damage about to occur to the stratospheric vortex we should at least be able to contemplate a less energetic jet stream and that in itself always leaves things open to meridonality, split jets and all sorts of other solutions in stark contrast to our current 'flat and fast' set up.

 

To use an anecdote to describe what we are seeing in terms of the potential (at long last!) for a pattern change, it's like cooking a chilli con carne. We are just sniffing at the first few hints of this - the mince just starting to cook in the wok (other cooking instruments are available). If we can see the NAEFS suite come on board with this idea in the next few days it will be the onion and tomato being added. We then get in to the nitty gritty of how far east/west the pattern sets up, how far south the jet can dig, how much jet energy goes over/under, and that's when we start adding the spices.

 

Subtle hints for now but NWP can be a very ambivalent mistress 15 days in to the future and it wouldn't be the first time she has made a fool of us all.

 

SK

[SnowBallz]

I suspect he'll soon be regretting his post! I would still love to know the resolution of mogreps-15 ???

 

Hi BA,

 

MOG-15 is a stochastic suite of 24 members which runs twice-daily, at 60km and across 70 vertical levels, on one of our machines sited at ECMWF.  This ensemble suite complements: MOG-G - 33km, and 70 vertical; (the now defunct) MOG-R - 18km, and 70 vertical, and finally MOG-UK - 2.2km, and again 70 vertical.

 

For completeness, GloSea5 (seasonal EPS) is another stochastic - but (as opposed to MOGs) coupled - suite of 42 members (21-day staggered creation) which runs at 60km atmospheric, and 0.25° oceanographic, out to a time-span of 6mths.

 

Hope that's helpful?

 

SB

[damianslaw]

As others have stated, there are signals for a more amplified flow developing over USA/Canada triggered by a slight shift west in the position of the polar vortex and more importantly weakening in its central core. Given the position of the PV, the key to a colder pattern developing is a shift to a more amplified pattern to our west. Such amplification is very likely to lead to trough disruption in the vicinity of the UK allowing heights to build and strengthen to our NE which as you approach the second half of Jan tend to be much more resilient against the atlantic compared to early winter - traditionally the PV and strength of the atlantic weakens through January.

 

Long term an easterly still looks very plausible provided an amplified pattern takes hold to our west.

[cooling climate]

An emerging number of MOGREPS members are starting to show much colder solutions by end of the trend period (15d). This hadn't been the case recently.

Although the stratosphere warming has backed off considerably from what it was showing

3 days ago when it looked as if we would see a possible SSW and pehaps major northern

hemisphere pattern change.

Their may well be strong enough wave breaking on our side of the pole to feed off the

stronger wave breaking on the Siberian side to create weak but sufficient heights to

the north/northeast with lower pressure to the south of the uk to produce a potentially

wintry set up cold enough for lying snow, frost etc.

This sort of set up could be far snowier IF it comes off than a very strong positive heights

to the north driving weather fronts and lows further to the south.

[Purga]

The 06z GEFS still mostly average and unsettled

 

 

But the odd rogue freeze up runs appearing to cheer.

 

For the SE

 

For the North a chunk of vortex where it should be!

 

[bluearmy]

Hi BA,

 

MOG-15 is a stochastic suite of 24 members which runs twice-daily, at 60km and across 70 vertical levels, on one of our machines sited at ECMWF.  This ensemble suite complements: MOG-G - 33km, and 70 vertical; (the now defunct) MOG-R - 18km, and 70 vertical, and finally MOG-UK - 2.2km, and again 70 vertical.

 

For completeness, GloSea5 (seasonal EPS) is another stochastic - but (as opposed to MOGs) coupled - suite of 42 members (21-day staggered creation) which runs at 60km atmospheric, and 0.25° oceanographic, out to a time-span of 6mths.

 

Hope that's helpful?

 

SB

 

many thanks SB -  70 vert levels puts it half way between ecm ens (91) and gefs (42) to day 8.  horizontally, its half the res of the ecm ens to day 10 (32km)  when it comes roughly into line.  post day 8, it is miles ahead of the gefs vertically (28) and marginally better res horizontally. (60 v 70). 

 

i guess it should be a good tool for the 11/15 day period and the forecasters can check its validity at day 10 against the ecm ens when they change to lower res.

[Iceni]

An emerging number of MOGREPS members are starting to show much colder solutions by end of the trend period (15d). This hadn't been the case recently.

 

 

Any chance of saying which direction Fergie?  I don't trust Scandi Highs much - they always seem to come to nothing even though they favour my location.

 

If it's more NW and Greenland tho' - now you're talking

Edited January 4, 2014 by Iceni

[Moisty]

Slightly off topic so forgive me. It's nice to see the tv forecasters getting a little more technical with their broadcasts, good explanation this morning of how the cold in the US and Canada has affected the jet stream and caused our wet weather. Even 2/3 years ago they would not have gone into that detail.

[johnholmes]

 

Thanks SK for as always a nice clear pretty starightforward commentary on the various factors at play.

Using my simply approach within the 6-15 day time frame from close and continuous scrutiny of the 500mb anomaly charts I see this.

There are two of the three I use fairly consistently showing both +ve heights of reasonable intensity and ridging in a similar area. That is from the pole area south into parts of Greenland. They are the 6-10 and 8-14 NOAA and the ten day GFS outputs. ECMWF has at times shown similar support but has also, like this morning, see below, put a trough where the other two have a ridge in the Greenland area. This difference stops me from putting my probability for a fairly marked change in upper wave lengths above 50% for now. The signal does appear fairly solid though from the other two. When two are showing similar providing one of them is the NOAA outputs then I tend to feel a bit more confidence in their outcome. So to me not a lot changing on the upper air major patterns for a week to 10 days. However, if we see all 3 of the 500mb anomaly charts continuing to show the actual 500mb flow north of 60N decreasing and maybe even suggesting some kind of ridging south then I would be putting the probability increasingly over 60%. If not then it might be back to the drawing board and relying on a more north of west Atlantic flow to give somewhat colder shots behind further surface low systems. Incidentally I think this is fairly likely now, say 5-7 days for this to start to show more often?

http://www.meteo.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

Edited January 4, 2014 by johnholmes

[Mucka]

Well we said things looked finely balanced and that is how it is proving. Things looked bleak this morning when the Operational's were out with all the main models moving away from any proper Easterly influence on our weather but the ECM ensembles, MetO's latest forecast and Ian's update all give more confidence.

ECM London ensembles are quite cold but I'm unsure how this mornings ECM Op gives an ice day on the 13th from this mornings run - that brief slack continental flow I guess? Still, a definite shift to colder with the mean just 3 or 4C and plenty of colder options from the 12th.

 

Some of you may have noticed the Winter hasn't been great thus far so I expect people would of made rather large emotional investments in the idea of colder, drier, snowier for the second half of January if we were seeing some outrageous eye candy with strong Northeasterlies and heavy snow being modelled - so perhaps it is better to be seeing the less cold patterns being modelled and keep expectations low. 

Given the conflicting signals there will be a fair amount of flip flopping as people have mentioned so I'm going to try and take some of my own advice and buckle up for the ride.

Exciting times at least.

 

 

 

Edited January 4, 2014 by Mucka

[draztik]

So, depending on whether the gfs ens have the correct synoptics pinned out to day 16, i thought it was interesting to see how the temp anomaly evolves for Europe. (Using gefs 6z suite)

Currently we have a very mild continent, a strong positive anomaly over western Europe and up into Scandinavia..

By day 10, this signal wanes, tho staying fairly positive over western Europe and the Balkans in particular. We see changes further north & east, and to our west. With colder conditions seemingly incoming.

By day 16, we have a very negative anomaly over Russia, encroaching into Eastern Europe. With Scandinavia and much of the British isles also below average. However, even by 20th Jan, western Europe (-UK) still remains with a fairly positive anomaly.

Fair to say, the ecm det, sees surface temps slightly differently...

Surface temp anomaly day 10.

[lorenzo]

Interesting times.. almost too much to make sense of at present.

 

MJO - first this animation loop shows the decaying signal as the MJO returns to the circle of doom. What could have been Phase 7-8-1, really looking like dissipating in phase 6 - 7.

http://cawcr.gov.au/staff/mwheeler/maproom/OLR_modes/JA.all.20to10.html

 

The models have really been at odds with each other on the MJO recently, here are some verification stats for week 1 and week 2, UKME did very well, with the recent GFS and GEFS looking wild.

 

Verification - Week 1 - Week 2 You can see ECM trending toward UKME initial solution for the most recent week, another qualification why we really need the UKMO 'onboard' between the ECM and GFS variance.

 

GWO plot from this morning highlights the pretty huge negative Asian mountain torque, ESRL seems to be offline this morning.

 

Also it cycles through towards phase 4 before returning to phase 2 in the forecast period, although this is visible in the ECM EPS, a definitive change within only 10 days. Potential torque event..?

 

With the vortex split at 100hPa at 168hrs and then forecast to reform, going to be some interesting modelling as the MJO forcing for phase 6 attempts to project a blockier outlook. circa 10th Jan.

 

Meanwhile CFS has been doing this with the Euro Temp anomalies. Edit - see draztik above looking at same trend on GEFS whilst contructing this post..

 

Hopefully, that next bite of the cherry isn't too far away..

 

Edited January 4, 2014 by lorenzo

[bluearmy]

tony, those temp comparisons are mid feb ! hope we dont have to wait that long for the cherry to come around again !!

[lorenzo]

Yep, nor do I ! The point was that they are trending colder, this Winter requires the patience of a Saint!

[Summer Sun]

Once again the latest NAO update shows no change with it remaining neutral for the foreseeable future

 

 

The latest AO update take its positive during next week after this we have a lot of scatter but not much scatter goes negative