Model Output Discussion; into 2015

[Gibby]

Apologies for lack of posting of late. Unfortunately spent a few days in RUH Bath with Kidney Stones and you can take it from me you don't want to get those. Anyway full praise to all the Doctors and Nurses in at Bath helped me to recovery quickly and get me back home to normal life. Meanwhile back on topic.

 

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY MONDAY JANUARY 5TH 2015.

NEXT UPDATE TUESDAY JANUARY 6TH 2015 08:00

THE CURRENT GENERAL SITUATION A warm front will move East across the UK today followed by a cold front moving SE tonight and tomorrow.

MODELS-2 WEEK HEADLINE  Rather changeable and sometimes mild with rain at times and strong winds too. Perhaps becoming quite stormy later and rather colder at times, especially in the North.

THE JET STREAM ENSEMBLE FORECAST The Jet Stream Forecast shows a strong Jet Stream being maintained across or to the South of the UK in the short to mid term before it quickly weakens later as the result of a possible pressure rise to the North and East of the UK later.

GFS OPERATIONAL The GFS operational continues to look very zonal, sometimes mild and wet, sometimes cooler and more showery but never particularly cold but nearly always very windy from a Westerly point. Later in the run though pressure rises sharply to the West and NW slipping East bringing a change to colder and drier weather with some wintry showers in the usual hotspots in the transition period with frosts at night for all then.

THE GFS PARALLEL RUN The Parallel run is similar but makes much less if anything of the rise of pressure at the end to the NW and instead rises pressure close to the South with attendant less chilly and wet weather as a result.

THE GFS CONTROL The GFS control run shows a very lively spell of weather to come with gales and heavy rain never far away from any one place at anytime. There will be spells of cooler and more showery weather with hail, thunder, sleet and snow possible here and there before the model follows the operational's route of drawing High pressure over the UK from the NW later with cold and frosty weather developing as a result.

THE GEFS ENSEMBLES The GFS Ensembles show strong support for a Westerly flow to dominate the UK for much of the period. Strong winds, heavy rain, showers, wintry on hills will be all in the mix before a more open verdict on where we will be in 14 days time is shown with about 20% of outcomes favouring a High pressure block close to the Nort Sea and Denmark at the end of the run with colder versions of unsettled weather elsewhere in the pack than we have currently.

UKMO UKMO shows a strong Westerly flow across the UK over the next 5 days with gales and heavy rain at times. It continues to refuse High pressure being very far away from the South or SW though through the period continuing to dilute the very worst of the stormy conditions towards more Northern areas of the UK rather than all areas.

THE FAX CHARTS The Fax Charts mirror the raw data quite well today showing the end of the week and strart to the weekend with yet another broad mild sector across England and Wales while Scotland and Northern Ireland continue with gales and rain from fronts rushing East in the flow but very slowly South.

GEM GEM today follows the very worn road of late with typical zonal January weather type with Low after Low moving East to the North of the UK with embedded fronts and strong winds delivering rain for all heavy at times especially across the North and West.

NAVGEM NAVGEM also shows a Westerly flow dominant across the UK over the next week or so. Some rain at times is likely for all but with some dry and bright spells at times too, none of which look like lasting very long.

ECM ECM this morning continues to promote Westerly winds across the UK. All areas can expect to see spells of rain and strong winds alternating with colder and more showery periods with a few frosts at night where skies clear and winds fall light enough between systems.

ECM 10 DAY MEAN The ECM 10 Day Mean Chart shows Low pressure to the North and High to the South the most likely scenario at Day 10. The trend towards this has been maintained for a long while now and there is no reason to suggest ECM still hasn't got a real handle on this situation most likely to evolve 10 days from now

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend this morning remains largely usettled and windy with spells of rain at times and short colder spells with showers. Some hints ony late in FI that High pressure might make an appearance over the UK from the NW..

MY THOUGHTS The very Atlantic driven spell of weather is set to continue for a long while yet with all models keen to show their own version of wind and rainy weather mixed with colder and brighter spells with lively showers especially across the West and North where they would be occasionally wintry over the hills. It is left to the far reaches of GFS's output to see any major swing away from this pattern as it's clusters do show a change to rather cooler zonality from the NW or as some grouping also is shown around the possibility of some sort of High pressure forming over or just to the East of the UK in 10 Days or so delivering a period of colder benign weather with the likelihood of frosts for most. Whichever route the models take the clock is ticking on another Winter month that cold lovers will feel bereaved if we still lie in this pattern two weeks from now but for the moment apart from the exceptions logged above the odds are very much still in favour of wet and windy weather far more likely through the middle phase of January rather than cold and snowy. The wait continues.

[mulzy]

No real change this morning.

 

There are hints of Atlantic amplification mid-month but nothing in the charts suggest sustained cold.  As ever, things can change quickly with NWP but till mid-month, expect zonality and a CET anomaly of at least +1C.

 

This week looks exceptionally mild at times - double digit maximums rather common especially in the south.

 

Edited January 5, 2015 by mulzy

[karlos1983]

GFS ends quite nicely in deep lala land, GFS(P) certainly looks like it's going to have a great tease from around +240 onward

and the 06z GFS ends with this at 10hpa.......

would be nice to see that continue as a trend . 

 

I shall be positive 

Edited January 5, 2015 by karlos1983

[IDO]

Spoiler low on the GFS op 06z: 

 

This delays the pressure rise and leads to heights displaced further east:

 

   

 

Not a bad end result but again anything decent is put back to D16+.

 

No short wave on the GFS P at D10: 

 

That sums up the uncertainty in how the height rises develop. To get the early chance we need the short waves to read the script. GEM have been going short wave crazy around D10 on the last few runs so I am not sure they will go for an early (ish) height rise. Though the GFS P is also going short wave mad at D12:

 

 And the pattern flattens: 

 

The problem is that now we are getting closer to the more reliable we get more mesoscale features that can kill the cold synoptics. Only one run but just highlights that the upcoming long wave pattern may be difficult to disrupt.

 

 

[BlueHedgehog074]

Apologies for lack of posting of late. Unfortunately spent a few days in RUH Bath with Kidney Stones and you can take it from me you don't want to get those. Anyway full praise to all the Doctors and Nurses in at Bath helped me to recovery quickly and get me back home to normal life. Meanwhile back on topic.

Glad you're feeling better, Gibby. Certainly sounds like the Doctors did a great job eradicating the problem.

Would agree that Atlantic drivern weather still seems to be the way to go. Hopefully some of the possible signs of the Atlantic slowing down and/or the weather pattern getting more amplified to the West in FI (just like on the GFS run) gathers more momentum as it could help to bring some cooler/colder conditions into the UK perhaps with Lows being forced to drop down to our East or South-East. (Would be good news for those of you wanting to see colder weather).

The NOAA 8 - 14 Day 500mb Anomaly chart, however, keeps the pattern Westerly drivern - a general Westerly flow over the UK at the 500mb level. Since it's more directly from the West rather than the South-West, and with the lower than average heights concentrated more to our North/North-East, it perhaps could mean seeing Westerly flows with more polar air getting into the mix at times. And also the possibility of the Vortex over Greenland/Canada becoming less intense. The chart doesn't seem to be buying into any significant ridging in the Atlantic at the moment with perhaps some kind of Atlantic troughing likely to continue.

[winterof79]

There is definately a signal for a block to form near our locale mid month.Its modelled to finish here on the 06z

http://modeles.meteociel.fr/modeles/gfs/runs/2015010506/gfsnh-0-384.png?6  and believe me that would create fun and games trying to shift that.

After 132z there is no mild weather modelled on the GFS and we are on the cold side of the trough

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=132&mode=1&carte=1

 

The PV looking a little punch drunk by mid month possibly the towel being thrown in by Feb

http://modeles.meteociel.fr/modeles/gfs/runs/2015010506/gfsnh-0-240.png?6

Edited January 5, 2015 by winterof79

[chionomaniac]

Trop based vortex split is there again both on GFS and parallel by day 15. This one holds more interest that any previous ones this winter because the Pacific heights aren't forecast to be as great which will mean less displacement of the vortex to the Atlantic sector. Promising.

 

PS don't be looking at the meteociel strat charts (for this) they don't show the geopotential heights only the temps. NW ones on extra are the best followed by Instant weather maps

 

Edited January 5, 2015 by chionomaniac

[winterof79]

Trop based vortex split is there again both on GFS and parallel by day 15. This one holds more interest that any previous ones this winter because the Pacific heights aren't forecast to be as great which will mean less displacement of the vortex to the Atlantic sector. Promising.

 

PS don't be looking at the meteociel strat charts they don't show the geopotential heights only the temps. NW ones on extra are the best followed by Instant weather maps

 

viewimage.png

Agreed Chio, i had just posted the observation myself although less scientifically.Thought i was on my own until i saw your post.Some times when you view output you just get thet feeling a little like Old Met Man does.Then there are the more technically gifted

[Newberryone]

Some good confidence from the models that the UK will get attacked by Atlantic Low Pressure systems this week. The flow mostly being from the West or South-West.The Azores High Pressure system looking to be too tired to try knock out that indestructible Vortex and its army of Atlantic Lows to our North-West. But the Azores High will, at least, hang about close by to our South. This should also mean Southern areas should avoid the worst of the unsettled conditions this week. However, no where will be totally free from rain this week as the Atlantic Lows use their cannon to fire frontal systems at us at times. Some cooler, brighter and, at times, showery interludes will occur between the bands of rain, but with Southern areas benefitting the most from the brighter interludes. Temperatures on the whole, though, most especially towards the South, will be mostly on the mild side.

Today, for example, will see a cold front greeting North-Western areas bringing some heavy rain and winds along with it. This will sink South-Eastwards overnight and clear South-Eastern areas later tomorrow. Brighter conditions following behind for most places tomorrow on a cool Westerly flow with a sprinkling of wintry showers towards the North-West. Another band of rain will then invade the country on Wednesday with the rest of this week continuing on a similar sort of vain - rain, showers (some wintry on hills), cloudy and brighter periods, etc.

A transient ridge quietening things down this coming weekend, but only temporarily as a reinvigorated PV seems to cause a strengthening of the jet stream next week, as indicated by the Ecm 00z op. Good to see Uncle Barty having less and less of an influence at least. 

[glenh]

GFS ensembles certainly seem to be firming up on a noticeable cool (and settle) down mid month:

 

 

[Nick F]

Long-way off Saturday and subject to moderation, but a pretty cold and strong NWly flow on Saturday from 06z GFS, with -6C to -7C T850s over most areas by evening.

 

 

ECM somewhat slower to bring in the cold polar flow, but by 00z Sunday:

 

 

Before then, looking increasingly stormy from mid-week, wet and windy weather spreading east Weds and Weds night, respite Thursday, then potential deep low passing north of Scotland on Friday, more on this in my in depth look at this week and beyond in my blog here:

 

http://www.netweather.tv/index.cgi?action=news;storyid=6382;sess=

Edited January 5, 2015 by Paul
Removed my post!

[IDO]

We are now up to about 80% of GEFS 06z at D14 having some sort of MLB or HLB so that continues the trend for a pressure rise:

 

 

The control, like the op has the spoiler low but also ends similarly: 

 

They do look the best case scenarios with respect to their ensembles though. Looking at the extended ECM temps I would be surprised if the ECM Ens do not reflect something similar cluster wise to the GEFS? Though saying that the GEM ENS remains quite immune to the GFS  take on FI:

 

   

 

Not even a trend showing. UKMO up to D16 shows no sign that the GFS trend is worth a mention. ECM will be entering range in the next 2 days so we shall see how the op goes. 

Edited January 5, 2015 by i'm dreaming of...

[seaside 60]

So its time this week, one less modal to take apart as being bias.

Sorry next week,  I think.

Bye bye GFS.
 

Edited January 5, 2015 by seaside 60

[snowblues]

As a basic look on how the pattern may evolve on the Atlantic ridge development.At the end frame on the ecm this morning you can see the deep low swinging in from the Atlantic also an other sweeping low coming straight down from the pole regions into the U.S.,the further south it digs the better,I would of thought a ridge of some sort must be on the cards if this is to follow some of the other models.

[johnholmes]

Gibby, on 05 Jan 2015 - 10:23, said:

Apologies for lack of posting of late. Unfortunately spent a few days in RUH Bath with Kidney Stones and you can take it from me you don't want to get those. Anyway full praise to all the Doctors and Nurses in at Bath helped me to recovery quickly and get me back home to normal life. Meanwhile back on topic.

glad you are ok again, yes they are not at all pleasant.

Edited January 5, 2015 by johnholmes

[seaside 60]

 

Gibby, on 05 Jan 2015 - 10:23, said:

glad you are ok again, yes they are not at all pleasant.

 

This sounds dodgy that's 2 people on here that had kidney stones over the xmas period.

[SE Blizzards]

Very interesting AO forecast update today, quite a fair bit of scatter, but most, if not all members heading downwards in a few days time, and a couple of members taking a good old tanking, going down as low as -4!

 

[karlos1983]

Certainly some interesting Purbs on the GEFS. In deep fl granted, but it's roughly half of them.

 

[legritter]

good afternoon All ,glad Gibby to see your postings ,and you are ok .well us coldies are still awaiting something more wintry and with the first half of winter nearly two weeks away and signs of the next week still according to models remaining mostly on the milder side except for some brief colder shots i thought i would for a change stick my kneck out a little .both GFS models do show today a colder synoptic situation out past 10 days and the end of ecm also looks wintry ,at the moment it looks like the azores high could become displaced further west and north ,and lows coming out of n/east states and canada heading further south .at this stage theres a possibility of much colder 850 mb temp flooding south and s/east across us hopefully .so any poster writing winter off dont as its only 5th january ,so here goes my forecast for the last half of january ,mother nature to balance the books ,low lying areas of england and wales to see snow ,some pretty cold nights possible ,some lucky posters some not ,this is all based on current data and reading forecasts from around the internet . i fully expect the GFS runs to become very changeable pretty soon ,and i,m expecting ecm tonight to be well liked ,its great to be a part of NWeather forum i dont personally like Roller Coasters but this one is great ,    .

[seaside 60]

I may have this wrong, but you might as well stop ;looking at the old GFS.

As per my previous post I think it gets switched off next week.
Can one of the mods confirm that.
 

[karlos1983]

I may have this wrong, but you might as well stop ;looking at the old GFS.

As per my previous post I think it gets switched off next week.

Can one of the mods confirm that.

 

 

Well it's working at the moment, so until it's gone people are going to view it and indeed comment on it. It is still using valid data, it's not making it up(kinda)

Edited January 5, 2015 by karlos1983

[TEITS]

One pattern which many haven't noticed over the past 4 or 5 days is how often the GFS & GEFS control run are always colder than the mean. As a consequence the SLP mean in Iceland is lower than the GFS Ops/Control. When this happens continuously then its worth taking note rather than being the odd outlier.

 

So my view remains the same it will turn colder from mid Jan onwards. The real tricky bit is this could range from a brief cold snap followed by mild W,lys. A classic N/NE,ly cold spell via blocking to our NW. Another scenario is a brief N,ly followed by blocking developing over Scandinavia bringing an E,ly.

 

Note some of the GEFS ensembles are colder in my location than Scotland. This can only occur via an E,ly!

 

http://max.nwstatic.co.uk/ensimages/ens.20150105/06/t850Cambridgeshire.png

 

Note GFS/Control reach 1020mb over Iceland, 1040mb Oslo

 

http://max.nwstatic.co.uk/ensimages/ens.20150105/06/prmslReyjavic.png

http://max.nwstatic.co.uk/ensimages/ens.20150105/06/prmslOslo.png

 

Problem is this is just out of the range of the ECM. So at the moment from an unbiased point of view of the models there is enough evidence to suggest it may turn colder but not enough evidence to ramp away at a potential big freeze.

[johnholmes]

Looking at what MJO data is available the current pattern in phase 5, low orbit though, shows a 500mb anomaly pattern pretty similar to what we have.

The few varieties available for its forecasts seem to support it moving into a low phase 6. This is not that much different again from what the 500mb pattern shows over the last few days. A bit less +/- anomalies which MIGHT mean there is more scope for more variability but nothing to suggest an upper ridge in any place favouring deep cold over anything more than brief outbreaks currently possible anyway.

phase 6 link below

http://www.americanwx.com/raleighwx/MJO/MJO.html

Edited January 5, 2015 by johnholmes

[snow freak]

This sounds dodgy that's 2 people on here that had kidney stones over the xmas period.

I had kidney stones a few years back and have never experienced pain like it before or since...thank heavens. 

[tcc]

Just a quick question for the resident experts on here, but the output we're seeing on GFS for later on this month, isn't this just a consequence of the GFS MJO forecast reaching 7 and 8? Which none of the others are showing as getting this far?

 

So how much faith do we put in this trend from GFS? I guess we'll have to wait and see when ECM brings but I'm not confident yet!