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

[Mucka]

Yes you're right re the USA it's very common over there, perhaps JH and Forecaster would supply me with the UKMO term for the American phasing, a term has to be used by the UKMO because its a very common synoptic situation.

 

Regarding some of the terms NOAA use, the recent addition was bombogenesis! that made me laugh, anyway I've been using the term phasing for years on here and am quite comfortable with it, I think its quite explanatory really.

 

Regarding the Pyrenees yes its turned very slushy and mild here now,  drizzly and underwhelming, some heavy snow though is expected tomorrow as it turns briefly colder. Overall though its been an excellent season, it seems strange to say that with all the mild muck but there was a lot of snow end of November, then sunny skies for nearly three weeks but with low dew points, no warm rain which is the real scurge of ski resorts.

 

More snow over Xmas, its just the last few days which has turned slushy, next week could turn warm but as long as its dry the resorts should be okay.

 

I'm not sure but I would take a guess at "conflate" or "coalesce"  but we could also use conjoin or commingle. 

The best definition of phasing in this context comes from the Oxford English dictionary: Phasing; the relationship between the timing of two or more events,

 

I'm not sure why I use "phasing", it seems a natural term but others probably better describe the interaction in a meteorological context.

 

Back to the MO. 

 

PS

 

Getting a little worried about my prediction that snow would fall to low levels in the North of England before mid month.

Edited January 3, 2014 by Mucka

[Froze were the Days]

If the CFS was right we would have been up to our necks in snow since the start of December.

 

Completely wrong statement - if you followed the 1 month and 6 month runs regularly form around October and November this simply wasn't the case. The posts which put up height anomalies (largely to our north or north east) were wrong, not sure where these came from - maybe from just 'chosen' runs and there weren't many good ones.

[Nimbus Nix]

Just noticed on the 06z GFS: Is that -111111111112°C at 850hpa near Moscow?

 

 

 

I'll have some of that if it comes our way...  

[draztik]

The Korean Met's forecast for Jan & Feb increasingly looking more favourable for cold. Its suggesting heights building over Scandinavia and Svalbard, with troughing to our NW, but this feature is not a strong signal, and any troughing looks likely to affect the NW. Looking longer term, mid feb the model builds these Scandi heights further, with blocking also indicated over Greenland. Low heights to the south of the UK & western Europe could lead to some very interesting weather types.

Mid feb height anomalies.

So, we have the jma and the kma keen for some form of northern blocking, while the ec32 sees it rather differently, less keen on blocking further north thru Jan. Have had a look at the latest ensemble forecast from cfs, but to be honest that model changes so much I don't see the relevance in posting it.

So, we have a bit of battle between the long range models. As Shed has said, patience is key.

[SMU]

Improving gfs ensembles as we go now with a few cliff divers in the mix now- all being brought about by the alteration in track-

Remember what I keep reminding us of- weather is about timing and storm tracks

In this instance a 200 mile change in storm track effects the WHOLE hemispheric pattern at day 8

Gfs 06z ptb 5 is a very plausable outcome and looks quite like the ukmo!

If people want a post on phasing let me know

We need a phasing of the 2 systems in america to happen then post that a phasing of 2 highs !!!!

S

[carinthian]

OK . this is the latest. In the fields of high-resolution variations models, a portal internet service provides short and medium range predictions for snowfall and in -house longer term forecast . Current calulations are for the period 10-24 th January 2014 and is a synoptic prediction for Europe generally.

The first few days will show the Atlantic flow holding temperatures above normal in most of Europe but with temperatures starting to fall to near average values above about 50 N. The jet weakening significantly with some amplification of the flow way out in the Atlantic. Cold air and pressure rises intensifies later in this period. About a 33% expectancy of a fall in pressure to the southwest of the British Isles and into Europe. This phase is crucial if colder air is the be advected from the NE across mainland Europe and the UK. 

 C

Just a follow up from yesterdays offering. Our short term forecasting system predicts substantial precipitation totals this weekend with some locally heavy falls of snow , mostly towards the Italian/ Swiss borders, mostly above 1500m. The fine mesh numericals predict 25 cm here in resort. Fohn conditions likely in the Northern Alps .

The longer term European synoptics 11-25 th January, show the maritime countries ( inc the UK ) into a colder regime and with a intensification of Arctic Continental cold IN North Europe. Southern and Central Europe starting with above average temperatures. A stronger mid-Atlantic ridge developing and an increased expectancy this morning of lower heights and cyclonic circulation developing in the region of Southern Britain towards the end of the forecast period. If this was to materialize , a snowy scenario would take over Southern Britain combined with the advent of cold air advection.

 C

Edited January 3, 2014 by carinthian

[lassie23]

Blocking seems most likely over scandinavia as the cold air coming out of canada into the north atlantic is scuppering any chances of a block forming over greenland. All eyes on the east?

[bluearmy]

looking through the latest anomoly and mean heights on the extended ecm and gfs, there is a trend to place neg height anomolys to our south but no desire to remove them from our northwest. remembering that these extended ens were also showing this a week or so ago for the upcoming period makes this seem unrelaible in any case (the euro low anomoly). there seems to be decent support for the east greeny heights to become cut off around day 8 so its a shame that the jet streak which follows is so strong and just blasts them aside. the next push of the jet seems weaker and placed further south so if we had managed to get these heights cut off and stable in that locale, we would have been in business. i just cant see where the positive vibes are coming from unless the ops are finally making the running here - and tbh, they are not consistent this morning from their promise of yesterday. as far as exeter's feeling of wintry patetrns being possible later in the month - i know ian stated that these were based on clustering of potentially cold sypnotic patterns in a fortnight but you would hardly say that the extended ecm ens are 'picking up the baton', nor the ec 32. maybe ian can help re whether there are any clusters of cold members on the latest ec 32 weeks 3 or 4.

[IDO]

The Oslo surface pressure charts has the Scandi High option of the FI 06z op as in the unlikely cluster; two other members support a more sustained pressure rise in that area:

 

 

The Arctic High lifespan appears to now be waning with about 33% losing that feature by T300 up to 66% by T384, with the Siberian high the main beneficiary. A T384 mean chart is of nominal value but it sort of highlights the point:

 

 

The JMA for the last two weeks of Jan is supportive of the EC32 update with a continuation of the current theme but with a lower amplitude:

 

 

The NAO ties in with the wax and wane of the Atlantic flow as the PV relaxes a bit:  

 

So as the op and Control from the GFS 06z show, another attempt at building an Atlantic ridge after T240.

 

So although the first lull next week has likely been a missed opportunity, another go is on the horizon, and with the residue height rises left from the initial attempt, it could force a pattern change. But unfortunately mid Jan at the earliest for something more seasonal for the glass half full viewers.

[snowking]

ECMWF not on board but GFS and UKMO continue to suggest a phase 7 progression of the MJO:

 

 

500mb height anomaly composites for which (taking in to account ENSO Neutral conditions and a West QBO) suggest this:

 

 

And gives an SLP anomaly of:

 

 

(Key composite years for such conditions are 1979 and 1981)

 

I would still be cautious until we see the three big guns all pointing in the same direction but putting aside for just a moment the warm vs cold debate in view of current conditions I think we could all do with something like this - certainly the potential for some cold from that but above all else something far drier and more settled.

 

SK

Edited January 3, 2014 by snowking

[sebastiaan1973]

Which model has the best MJO forecast? Any verifications available?

[Man With Beard]

Top posts this afternoon from Draztik, Carinthian and Snowking, thanks!

 

Well it's amazing how long-term model viewers could be as pessimistic as optimistic about the 00/06Z charts! When I posted at 4.50am this morning I was particularly pleased with the northerly height rises suggested by the UKMO as, like some, I see it as the one model you want on your side if its HLB you are after. Clearly seeing the ECM not coming up with anything particularly wintery has dampened the enthusiasm of some.

 

But I think there is a different trend to keep an eye on now; the GFS 00Z and 06Z (along with control run) have all shown a further rise in pressure towards Iceland at around 12th January and, with the Polar Vortex having been a little weakened by then, this pressure rise seems more likely to hold. The eventual result may differ - the 00Z produced an Icelandic High (great for cold), the 06Z led to a Scandinavian High (possibly fantastic for cold) and the 06Z control run ended with a UK High (cold but not snowy). But its the consistency of the pressure rise that is starting to get my attention. I will be watching this closely over the next couple of days to see if it gets picked up by the ECM and if the trend firms up more.  

 

I find pattern changes often happen like this - one attempt to change the pattern is closely followed by another - and sometimes it takes two attempts to break it. Encouraging signs coming from some other models too. So January is far from a lost cause as things stand. The real cold-chasing game, I feel, is about to begin.

Edited January 3, 2014 by rjbw

[R.P. McMurphy]

Which model has the best MJO forecast? Any verifications available?

 

ECMWF has the highest skill of all the models for MJO.

[Summer Sun]

No change in today's NAO update with it remaining neutral to at least mid month

 

 

The latest AO update goes positive for a time next week after starting negative towards mid month it heads negative again albeit with a lot of scatter

 

[legritter]

Top posts this afternoon from Draztik, Carinthian and Snowking, thanks!

 

Well it's amazing how long-term model viewers could be as pessimistic as optimistic about the 00/06Z charts! When I posted at 4.50am this morning I was particularly pleased with the northerly height rises suggested by the UKMO as, like some, I see it as the one model you want on your side if its HLB you are after. Clearly seeing the ECM not coming up with anything particularly wintery has dampened the enthusiasm of some.

 

But I think there is a different trend to keep an eye on now; the GFS 00Z and 06Z (along with control run) have all shown a further rise in pressure towards Iceland at around 12th January and, with the Polar Vortex having been a little weakened by then, this pressure rise seems more likely to hold. The eventual result may differ - the 00Z produced an Icelandic High (great for cold), the 06Z led to a Scandinavian High (possibly fantastic for cold) and the 06Z control run ended with a UK High (cold but not snowy). But its the consistency that is starting to get my attention. I will be watching this closely over the next couple of days to see if it gets picked up by the ECM and if the trend firms up more.  

 

I find pattern changes often happen like this - one attempt to change the pattern is closely followed by another - and sometimes it takes two attempts to break it. Encouraging signs coming from some other models too. So January is far from a lost cause as things stand. The real cold-chasing game, I feel, is about to begin.

A good sign ,we i feel are starting to see a possible stop to this zonal Slaughter ,realy hope to see some beefing up of the charts and hopefully all models singing together .and its great that we have plenty of winter left .

[Summer Sun]

Some of the driest ensembles we've had over a 2 week period in a long long time UK wide about time as well

 

 

A change to drier conditions looks likely during next week and something cooler could be on the cards from around mid month

[JK1]

Some of the driest ensembles we've had over a 2 week period in a long long time UK wide about time as well

 

 

A change to drier conditions looks likely during next week and something cooler could be on the cards from around mid month

I hope it's mild dry..

 

we do need dry weather though been very wet

Edited January 3, 2014 by JK1

[nick sussex]

Seeing as I'm a little superstitious I thought I'd post up the latest NAM from the USA, last night I reported on this being more amplified than its earlier solution. I'm happy to report that the 12hrs has added more amplification upstream to the 06hrs, the GFS thankfully did trend more amplified on its 18hrs run so lets hope that we see the same trend again  across all the outputs this evening.

 

So this is the 12hrs to T78hrs:

 

 

And the 06hrs to T84hrs:

 

 

You can see the shift there on the 12hrs taking the track of the low more n/ne.

 

In terms of the latest from the State forecasts, from New York:

 

...LOOK FOR THE SURFACE LOW TO DEEPEN AS IT LIFTSNORTH-NORTHEAST...REACHING THE SAINT LAWRENCE VALLEY BY MONDAYMORNING. THIS WESTERN TRACK NOW FAVORED BY ALL MODELS...AND SEEMSREASONABLE GIVEN THE POSITION OF THE LARGE UPPER LOW/TROUGH ALONGWITH INDICATIONS THAT THE UPPER TROUGH WILL TAKE ON A NEGATIVETILT FOR A TIME SUNDAY NIGHT INTO MONDAY MORNING.

 

The negative tilt is certainly a plus, anyway not long now till the evening outputs.

 

PS I've just had a look at the respective 03 and 09hrs SREF short range ensemble forecast for the USA and Canada, the 09hrs is also more amplified with a more favourably orientated low over the ne USA. Lets keep our fingers crossed here because the latest info does point to a bit more amplification and a westwards correction in track.

Edited January 3, 2014 by nick sussex

[R.P. McMurphy]

Hi Nick,

 

The post you just made, can you clarify what impact this will have on the UK weather (If any), and also what the "Upstream" part refers to or does please as I don't understand these charts at all let alone see what country it's over, but presume it's the good ol' US of A?

Edited January 3, 2014 by Glenn W

[nick sussex]

Hi Nick,

 

The post you just made, can you clarify what impact this will have on the UK weather (If any), and also what the "Upstream" part refers to or does please as I don't understand these charts at all let alone see what country it's over, but presume it's the good ol' US of A?

Hi Glenn

 

The upstream USA/Canada is crucial downstream in Europe in this instance, we need the low to run as far inland as possible and not out to sea because downstream this will develop a better ridge and give us more time for the high pressure to the north to force the troughing over the UK further east/se.

 

Its very much about timing and trying to hold back the PV for as long as possible.

[mcweather]

The last two GFS runs have shown a change in the pattern that may gives us a chance of something colder after mid month.

Of course its all in FI  as some wise heads have pointed out.

 

To be fair to the GFS at least the yanks have the balls to put their FI out for public scrutiny unlike the other big two.

 

Again wise heads have pointed out the extremely low verification rates of all models at that range.  This of course is good news

because at that range it means the GFS has got as much chance of being correct with the pattern as any other model.

Edited January 3, 2014 by mcweather

[Cloud 10]

The 12z NAE follows on from its last run in showing a snow event for parts of Ireland 

tomorrow morning.

 

 

The met-office have yellow warning's out for areas much further East than this

and stress the uncertainty regarding this feature.

 

Met Office: UK: severe weather warnings

[cooling climate]

If we get enough wave two amplification and warming the northern blocking and

cold synoptics will come with the likely hood of a high pressure to the north/north

east of the UK.

This sort of pattern would be less reliant on timing as it is an actual pattern change

rather than trying to find glimmers of cold in an otherwise zonal pattern where timing

is crucial.

[BLAST FROM THE PAST]

The reasons for optimism are IMO clear, before New Year it was zonal for years, now we have blocked and cold solutions appearing

 

More action from our big yellow friend ongoing and forecast to happen next week, for me I think more affects on jetstream pattern

 

Been catching up with the news and the SW.....oh boy with whats still to come over next 4-5 days its not good

 

BFTP

Edited January 3, 2014 by BLAST FROM THE PAST

[Continental Climate]

Not sure this is going to amount to much http://www.wetterzentrale.de/pics/Rtavn1381.png!! I think its all a little bit too early for any serious blocking to take hold its all pretty half-hearted at the moment if at all. There is still too much energy in the system and I really wish that lobe of the vortex would bugger off from north eastern Canada there isn't a worse place for it to just sit there. No serious cold to hit our shores until 21st - 25th is still my shout.

 

High heights in Europe are a pain as well albeit a fair reflection of the rut we are currently stuck in!!

Edited January 3, 2014 by Continental Climate