Model discussion highlights

[Battleground Snow]

Mjo doing an interesting loop back into 7 on today's update.

Could be helpful for maintaining the blocking signal further into March.

Mjo doing an interesting loop back into 7 on today's update.

Could be helpful for maintaining the blocking signal further into March.

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4806990

[bluearmy]

2 minutes ago, Bricriu said:

If the UKMO long range is to believed this SSW is not going to deliver, at least not before the 18th of March anyway. A very poor update.  You would think at this stage Glosea has factored in the  fallout of the SSW in its output for March. 

Well glosea was clearly showing a v cold snap cluster up until today 

But looks to have lost that - they mention low systems heading into the south of the U.K. which fits with HLB to our north - but seems that the air involved won’t be cold enough to bring lowland wintry conditions judging by that update. 

given that Exeter have access to all the strat data, this is a concern for coldies 

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807077

[Derecho]

15 minutes ago, Scandinavian High. said:

With major Sudden stratosphere warming going on is it possible for 2018 deep Freeze when should we start seeing effects of ssw within models ecm gfs gem or has started all ready.

I remember the GFS was hinting at something 12/13 days in advance and then the EC I remember had a proper beast at day 10. The models then chopped and changed for a bit before sticking to the easterly from about a week beforehand. The coldest of the uppers were pushed back by about 2 days.

Though just because we have an SSW doesn't mean we'll get a bitterly cold easterly, it just means we will likely see a split in the Polar Vortex. I feel those who are putting all their eggs in one basket could end up being let down.

Other factors may well have contributed to the BFTE, the MJO went through an extreme phase a few weeks before March and there was a Scandi high theme earlier on in February 2018 and SLP was often higher then normal through the month to our NE. The building blocks for a BFTE appeared as early as 17th February 2018.

If we want to see extreme cold, I think we will need some big changes in the next few days. When we get to mid-March the coldest days often rely on it being cloudy as the incoming solar radiation is greater at that point. We can still get very cold weather but we require even more variables to fall in exactly the right place.

 

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4806898

[Eagle Eye]

By day 10-12 ish the tropical wave suppression and extension seems to me like it should be associated with the retracting and extension of baracolic eddies as they drive the weather around them. In this case it may be below them. Not a direct effect of the SSW but without a strong Vortex above it flushing westerlies down and more localised reversed zonal winds above, seems to me like that allows room for the eddies to have a strong effect on tropospheric weather. This won't be Strat dictated but eddies are at their strongest (when non planetary as they are in the Strat) in the Tropopause and you can see the influence sort of like a lid from above. Meaning that the weather will start to really have a fluidity to it with more influence of MJO, AAM and Eddy effects compared to the zonal winds. As this looks to me like the Eddy driven jet is spreading out. If we can get upwards Wave flux to act on the SSW then it should be easier than usual for it to push down so it should be quicker but the trouble is the direction isn't right at the moment but still some Eddy's heading in that direction for it to downwell. Its interesting how this'll evolve.

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807173

[Catacol]

10 hours ago, Met4Cast said:

I think this whole scenario has highlighted how important and useful teleconnections such as the GSDM/GWO can be in predicting medium range weather. It became clear almost a week ago now that next weeks ridging probably wouldn't make it into Greenland. It's a valiant effort from the MJO to pump up a ridge in the Atlantic but the Canadian vortex lobe is too over powering and it never quite makes Greenland before toppling over the UK, this is before any impacts from the SSW. 

The second round of warming towards the end of this month will likely deliver the final blow, in conjunction with rising AAM in response to the recent MJO phasing & subsequent rise in +FT & probably then +MT timing will be perhaps better for more favourable downwelling of the -ve anomalies from the stratosphere into the troposphere. 

I'd not be surprised to see signs of blocking finally making it into the Greenland locale by the 2nd week of March & this then would bring the potential for a deeper cold spell of weather, albeit with increasingly diminishing returns as the days grow longer & the suns strength grows ever longer. The further into March we go the more "perfect" we need the synoptic pattern to deliver widespread low level snowfall.

Interesting post - but not sure about reference to GWO as a forecasting tool. The GWO orbit through February has seen a reversal of the move towards Nina phases

but as a forecasting tool how useful was this? Earlier in the month momentum looked to be falling and the GWO also….and then the recovery. Was this rise “forecastable” and therefore useful as a forward looking tool? Seems to me that the GWO orbit is a very good hindcast tool. We can see the imprint of the waxing and waning of a mid lat block that has kept the worst of the rain at bay after the event.

As for the MJO it has been heading through the IO through late January and, as such, was never likely to be boosting the high latitude blocking signal. The MJO is better as a forecasting tool as the cycle is visible and - to some extent - predictable. I don’t see where the valiant effort came from though - early to mid Feb it rapidly transitioned through phases 4 and 5 neither of which promotes cold blocking. Now that it is into the western Pacific we will see a positive influence in terms of supporting a colder outlook, but lagged impacts are 10-25 days after….so last week of Feb and through into March.

Agree therefore that a Greenland block is the form horse going forward particularly given what is happening in the stratosphere but this disappointing February was supported by the MJO rather than occurring in spite of it. The GWO orbit then acts like Hansard.

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807200

[Tills]

37 minutes ago, BLAST FROM THE PAST said:

More than feasible.  GFS knows what’s coming, date record challenging cold in March.

 

BFTP

 

It might know what is right but it seems pretty unsure of itself?

No real support from the ECM. UKMO extended doesn't look particularly positive for a cold setup either. Not to mention last night's 18z GFS run.

We are, or should be, still a long way from sensible talk about record cold in March. It might just as easily be the opposite if ECM is right. No guarantees right now that the ssw is going to play out for any downstream cold in the UK as yet. Can we keep our feet on the ground for now? 

 

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807285

[sunnijim]

16 minutes ago, BLAST FROM THE PAST said:

 

We got a little while for the 5 days out yet.  .  Enjoy the ride, only a few days ago and nothing was showing of interest.  The chart I showed at t336 is the type of synoptic result I believe will occur due to this SSW event, and not necessarily by 5th March.  It could be a little longer.  I think the idea that HP builds over us and to our east to bring an e to se flow to start ball rolling looks generally right.  Then I look for the PV to shift to Asia side.  Just going to enjoy the model rollercoaster from here

 

BFTP

I'm going to pre-emt the GFS "off on one posts' that will follow soon surely!

Worth remembering it hasn't been so wrong this winter has it?

The criticism maybe that it overreacts to a signal and runs with it before taking a ' few steps back at the 11th hour'

However, I'm not convinced it was so wrong compared to the lorded ECM and Ukmo during the recent failed Scandi high debacle.

Both UKMO and ECM kept the High too far South and West before moving toward the GFS solution at the 11th hour, leading to several days of cold blue skies and hard overnight frosts in an Easterly airflow here in the SE.

Sure the GFS shifted the High centre from Russia to Southern Denmark but my point is that all models met in the middle rather than one model being fundamently wrong.

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807304

[bluearmy]

Absolutely no argument that at we are seeing the strat imprinting down into the trop later in week 2 

but where will the Atlantic amplification actually verify ??  How slow will the lower strat and hence the upper levels of the trop drop to - too slow and we move towards talk of west based neg NAO’s …. Too fast and we have the ridge in the east Atlantic sector 

given that we will be in March, it really matters where the pieces of the puzzle fall - I’m still of the opinion that away from elevation and generally the north of the country it will be a struggle for a decent snowfall.  But it certainly looks like we won’t see the U.K. fall on the mild side of the pattern in a west or southerly flow 

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807324

[Cambrian]

The 6z GFS ensemble mean is an exciting one for setting out the scope for cold weather patterns over the next couple of weeks. 

At day 5, it has the northerly doing what northerlies do best - getting cold air in quickly. Looking like a good little blast this one. 

  

By day 8, the same chilly air remains in place, high pressure formed over southern Scandinavia, far enough north to be pulling cold air west over Europe into the south of the UK.  Look at that upper low developing over northern Italy. That’s handy.

  

It bumps the high a bit further north over Norway by day 10, continuing the advection of cold air west.

  

The ensemble means today are a bit noisy in week 2, more of a range and inter-run variability than usual, but from there at day 10, it looks set quite cold to me with the GFS looking the most promising. 

The ECM has the same broad setup but with the high further south, and there’s less westward advection of cold air through the continent.

  

For me, it’s tempting to think that the ECM mean has it about right for now. We’ve struggled all winter to get surface high pressure to the north of us that quickly. That high won’t be able to get that much further north or west until the low heights have completed their leakage out of the Canadian Arctic to the Siberian side.

March can often be a different kettle of fish for proper northerly blocking though, and it looks like this could well happen this time, but a bit later on, maybe towards the end of the first week of March going into the second, as the PV continues its heave over to the Siberian side, heights can at last build up through Iceland into Greenland. 

To go back to the ECM extended mean pressure anomalies forecast from Thursday, the neutral ‘gap’ runs from the pole - Greenland - Iceland - UK and Ireland, with lower pressure from Siberia to Scandinavia, so due to the cross-polar flow consistently being signalled, I still think we’ll get renewed northerly plunges at some point in the first half of March, perhaps interspersed with easterlies as the high oscillates between Greenland and Iceland. 

That would be a great way to sign off on 2023 Q1 - the optimal setup of wider chances for wintry precipitation off the northerly episodes, being consolidated by crisp, frosty periods in between. Could get a surprisingly general white spell off this. Have a great day. 

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807409

[minus10]

Eps and Gefs anoms showing clear strong height anomaly just to the north/north east of uk at turn of month..

...so it seems fairly clear the direction of travel if these are to be believed...dryish, cool/cold, frost at night but not severe (yet)...

...also of interest according to 'weather is cool' is that today is a record for the weakest 60N zonal  10hpa wind at - 12.1m/s...beating the previous record of - 11.8 m/s in 2001..(gfs analysis)..will that have implications down the line?

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807398

[That ECM]

1 minute ago, Bricriu said:

They are not getting delayed. It has been well flagged that any noteworthy cold due to the SSW is probably unlikely till the 2nd week of March. The recent EC46  suggested as late as week 3. The previous UKMO update did not have anything really cold before Mid March 

I think it’s going to be a slow response to the ssw and as such I’ve had fiver on Bournemouth having a white Christmas.

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807440

[phil nw.]

I have been quietly monitoring things from the sidelines the last few days waiting for signs of the warming effects.

I think it's reasonable to say that there are now clear signs in week 2 of a response to the filtering down of the Strat.reversal.now at 10hPa.

A look at yesterday's ecm strat zw forecasts show zonal winds are forecasted to get close to zero at 30hPa by day 10 and down to 3/4 m/s lower down.

The strat pattern looks to be imprinting on the 500 pattern with the vortex draining towards Scandinavia/Russia and clear support on Atlantic ridging.

This trend along with increasing momentum from the MJO phase 7 should see a continuing build of heights into the Arctic and a trough to our east.

For once notice can be taken of the week 2 charts I reckon.

 

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807656

[Cambrian]

The relocation of the core PV from the Canadian to Siberian side of the Arctic from day 8 to day 15/16 continues to be prove irresistible viewing, a handsome process here on the 12z ECM and GFS ensemble means…

 

a further advance on the 0z runs for the both, once they get through their awkward day 10 spooky purple alien  phase. 

  

It’s a transformation on a hemispheric scale, the core PV moving from 8 o’clock to 3 o’clock on the dial, the main southward troughing transferring from the western Atlantic to Eastern Europe. 

Heights free to roam northwest to southern Greenland as the Atlantic trough pulls back to the Canadian seaboard, our high pressure beginning to retrogress west and make way for the colder air working in from the north and east. An elegant evolution. 

 

Keep an eye on the -4 and -6 degree T850 isotherms in the later stages as well, sinking south through Iceland and Scandinavia, as the longwave trough digs a northerly down its western flank, maybe the curtains coming down on any prospect of an early Northern European spring. 

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807653

[bluearmy]

5 minutes ago, nick sussex said:

Once again the GEFS mean strat  forecasts and zonal winds is all over the place lower down .

Theres no consistency with the downwelling . This mornings ramps up the westerlies which would normally preclude a higher latitude block until much later .

Other forecasts which show latitude have the burst of westerlies dissipating by the end of the month and the downwelling well into the troposphere.

As expected, the second warming and reversal means the strat below 50hpa finally loses the Canadian trough extension by day 10 and that allows the ridging to the west of the U.K.  to establish at a latitude that allows it head further north which consequently brings cold further south 

that’s the current op trend and the number of eps that don’t find this increased amplification is diminishing rapidly 

There are still many obstacles before we bring any deep cold to the U.K.  the gfs is pretty much the coldest scenario on offer across the model suites this morning 

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807814

[Mucka]

For those wondering why some people are a little more optimistic about this FI, it is because the background signals align, the longer range models pressure anomalies are strongly in favour, and the signal is overall growing across the output

Obviously it can still go wrong, it is the rule of thumb for UK cold patterns, but this isn't just a normal FI chase where we scramble to look for support for a cold forecast such as GFS phantom Easterly of recent times.

Just flick between ECM 9 and 10 day mean (open in different tabs or use the site ). When you see a clear retrograde pattern showing that far out in the mean charts you know it is a very strong signal

If we can get the signal for retrogression into day 7 and 8 I will feel very confident because these sort of patterns though rare are more reliable when they occur because the Atlantic must undercut to get the high retrogressing which means we  all but eliminate our usual spoiler of low pressure developing around SW Greenland, preventing high pressure building far enough N and ultimate toppling the high, once that retrograde pattern is established.

In these scenarios the spoiler is the high sinking back SE (not toppling) because there isn't enough forcing from the Arctic on the E flank to cut back SW.

With the SSW and PV displacement to our NE that much less likely.

In short, all the pieces are there that make up Greenland High and classic Arctic plunge S/SE into NW Europe and hopefully across the UK.

The only worry is that is still in FI and the models have missed a key development.

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807926

[Met4Cast]

Looking at the models with the broader MJO composites it seems to me they are now reacting to the recent transition through phase 7. During February this broadly correlates to a toppler ridge out into the Atlantic however as we progress into March this begins to correlate more strongly to high pressure north of the UK, precisely what modelling is showing. 

 

Whilst the anomalies on the composites above are far too extreme, it does paint the broader picture & shows well the likely switch to a -NAO pattern as we go into early March. If we look at previous SSW's that have successful downwelling into the troposphere, we tend to see a "drip" scenario which can and often does result in a waxing and waning of blocking areas of high pressure, i.e potential for a couple of rounds of blocking. Note: When I say "blocking" I'm talking purely about high pressure, not about their potential impacts re: cold weather likelihood etc

Increased poleward flux ahead of the next bout of stratospheric warming (this doesn't count as a second SSW, it's all one SSW, you need 20-30 days of westerlies between SSW's for them to be classified as separate) whilst likely a factor in triggering the next warming will also help with a faster trop response due to the already weakened of the vortex so it's not unfeasible we'll tropospheric impacts by the end of the first week of March. Our block then, initially MJO led supported by the current +ve AAM (which after a brief stall will likely begin rising again as +ve MT kicks in following the recent +ve FT).

So, what conclusions can we draw? 

High latitude blocking likely early-mid March, perhaps producing multiple blocking episodes

Increased risk of cold weather outbreaks but not yet possible to ascertain exact placement of blocks

UK likely to see a continuation of very dry weather through March 

In terms of any cold, how cold & where mid latitude cold outbreaks will be (they're likely, but where?) that remains to be seen. 

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807935

[mushymanrob]

22 hours ago, Chesil View said:

Trusting any model beyond 7days at most is a fool errand and that includes the sainted ecm. Been plenty of garden paths from that over years.  7-10 days may possibly give an inkling but not much judging by how often the bbc telrvised ten days ahead outlook changes in its latter stages and that is normally a straight lift from the ecm.

Gfs will always have more of a garden path reputation simply because it goes out further publicly than the others.

 

Sorry but i dont agree with this one bit.

Its rubbishing all the other medium term predictive suites like the MJO, Clusters, Anomalies, ENSO, etc etc etc... All of these can and do point to which operational charts beyone 7 days are most likely to be accurate. Many of us have and do use these suites to accurately predict the likely pattern beyond 7 days and i/we have done so on here many times.

Talking of the Anomalies, the NOAA centred on March 1st, the EPS for March 6th are consistent in building a strong high over Greenland , the NOAA haeding that way, the EPS and many other medium range anomalies all agree on this.

So the snowmageddon charts the GFS are churning out in FI, DO have some merit, let alone the more "normal" colder charts they are predicting after next weekend.

These charts do not show another BFTE imho, in 2018 the northern block was more over Scandinavia, this time its Greenland.

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807839

[Met4Cast]

3 minutes ago, Lukesluckybunch said:

retrogression doesnt make it on the 12z..this is what i said other day...about that low to the southwest..it bumps into the high and we are left with southeast winds!

You seem very reactionary to each individual run of the model, you'll pass out from exhaustion in a week or two if you keep that up!

Deterministic runs need to be used in conjunction with the ensemble suites to get a clearer idea of the route forward. You wouldn't pick ensemble 15 lets say and hang every thought and hope on that 1 single ensemble run each and every time the model updates, so why do that with the deterministic? It's just another ensemble member. The evolution is going to constantly chop and change as models try to find the solution forward. The ensembles will be the best guidance, individual det runs less so.

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4807996

[Mike Poole]

ECM clusters - not sure we’re much further forward this evening.  T192-T240, 4 clusters:

Cluster 1 maybe ahead with the retrogression signal at day 10, with 2 not far behind.  Cluster 4 looks rather different and I would suggest is ‘against the run of play’.

T264+:

Cluster 2 is the clean retrogression, vortex migration one, looks excellent, much as it has looked on the last couple of runs, now with 21 members.  Cluster 1 looks messier, maybe a ragbag cluster of evolutions that aren’t cluster 2?  

So I think it is a hold rather than upgrade or downgrade this evening.  

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4808102

[mushymanrob]

The NOAA anomaly chart centred on the 2nd, does start to build heights over Greenland. The EPS for the 7th suggests, consistently, that a strong Greenland high will establish with low pressure over Siberia extending through Europe into Iberia.

This is about the coldest chart you could imagine.

In a couple of days time i expect (because they dont go out as far as the EPS) the NOAA charts to fully support the EPS evolution. March will get a cold pattern, but obviously, the detail cannot be known just yet.

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4808378

[Cambrian]

The overall trend and resulting setup is there run after run now. As others have pointed out, the 0z ECM day 15 ensemble mean and control are pearls, if you like fascinating spells of weather and are looking out for a cold spell. If you’re looking out for a swift return to climactic norms and something a bit milder, then please on this occasion look away! 

 

What is striking about this pair though is how well the mean supports the control - alignment and elongation of the Eurasian PV highly similar, heights into Greenland and Canadian Arctic high on the both, northerly flow into the UK and Ireland established in the two, low heights profile into Northern Europe also very similar. 

The jet stream profiles are similar too between mean and control. The mean jet stream charts always lose content in week 2 as features are averaged out. But look at the exit of the jet stream from the northeast US in the same position, a long way south - the directions on the arrows show it running southeast from there, and the North African jet is in the same place too. On the control, we only have a southward diving mini-jet stream coming out of Greenland, fortifying the Siberian trough.

 

A fair counter-argument would be that one would expect the control and mean of the same modelling system to look similar. But there is consistent cross-model agreement too. Here are the 0z GFS ensemble mean charts for day 16, showing pretty much the same route ahead as the ECM - long Arctic sea track northerly flow into the UK and Ireland coinciding with the seas being at their coldest, heading down towards the base of the trough as also indicated by the ECM control jet stream - an increasingly cold, increasingly cyclonic outlook. 

   

(The 6z GFS means on their way will no doubt show very similar or possibly an advance, but I wanted to keep the time stamps consistent for the comparison). 

We all know that modelling of the weather two weeks away can change a great deal in the interim, but if the currently consistent modelling of such an entrenched broad pattern is correct, with plenty of wriggle room for deviations that would still deliver similarly, in around a fortnight, we may well be entering a particularly memorable period of weather. Have a great start to the week.

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4808406

[Cold Winter Night]

As it stands, we can be quite confident that during Day 4-9 we will see a Scandi High getting established, building from the Atlantic through the UK (classic development).
The EPS ensemble regime chart shows the move towards a Positive Blocking episode with good amplitude.

This will bring in Easterlies from Day 6 to Day 10 at least, ending February -and also the meteorological winter- on a colder note.

After that, I see much agreement on the general, big picture developments in the extended, and longer term deep into March, with heights somewhere near Greenland and the tPV setting up in the Eastern hemisphere.
Those are good looking synoptics from a distance, but the details up close might be more stubborn. I’m still very much on the fence when it comes to our lived experience on the ground.

As others have alluded to, the ensembles suggest that there is a serious risk of the Greenland heights setting up a bit far West. Right on the edge perhaps, reminiscent of last December, or a genuine West based Neg. NAO.

The EPS 0z wind direction chart for De Bilt this shows a return of SW/W/NW winds within 15 days, which is associated with heights over West Greenland, and an outflow of cold further to our Northwest.

Coldies in Scotland, Northern England and Northern Ireland could very well be in a better, more lucky position than those of us further South and East.

To be honest, I expected wilder ensemble swings after the SSW than we’ve seen so far; the spread in the extended isn’t that huge.
But it’s still deep FI and there is plenty of time and uncertainty left for corrections East.
The effects of the probable second stratospheric warming could hit us well beyond the reach of today's regular ensemble as well.

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4808430

[Cambrian]

The 6z GFS end of run ensemble mean is arguably even more on point. 

More definite Siberia-Scandinavia-UK and Ireland trough, lower heights and pressure clearly working their way southwest. Maybe a tussle with the potential for a west-based -ve NAO on the way with the lower heights in the Atlantic, but by the same token, that could equally be great for one almighty battleground setup. A long way to go with that one, and those impressive heights at that range over southern Greenland are comforting. 

 

A point about the uppers not being that impressive - fair enough, they’re not. But statistically, with the guaranteed ensemble spread, it’s a big ask to output a snow-giving T850 at day 16. 

 

The trend is important, here’s the T850 anomaly from day 8 to 16 which better picks up the subtle, but definite, trend in the mean, steadily colder and colder air moving down through Scandinavia and the Norwegian Sea towards the UK and Ireland. A great trajectory. 

(Sorry for the typo on the last post, I meant “climatic” not “climactic” - mind you, if what is shown on many of the charts transpires, the jury might well be out on that one for the most avid coldies. ). These are great times for our huge fascination. 

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4808445

[Uncertainty]

I’m surprised by the lack of enthusiasm for this spell on this thread. We spend years looking for charts like this and now they’re coming there’s barely any interest.
 

I looked back through the 2018 threads and the difference is remarkable: joy, anticipation, camaraderie, detailed analysis. This time I’m sorry to say it’s been cynicism, doubt and a general feeling of ‘whatever’.
 

This is not a diss at any one person, on the contrary, it is a call to arms: Let’s inject some passion and excitement (not to be confused with hyperbole or inaccuracy mind) into this thread. We may be looking at an exceptional late Feb/early March spell (as many of us have been suggesting for months) and our commentary will be vital for many learners and observers looking for the truth amongst the ridiculous headlines and naysayers. As I have stressed before, the internet is quick to judge this thread and it’s reputation has taken a hiding in recent years.  We spend enough time on here… let’s make it worthwhile

First up: The icon has snow showers peppering the east coast early next week. It has sharpened the initial amplification as the day has gone on, the jet angle is now near vertical.

This is a key component to a snowy easterly, and we should look closely at the gem and gfs to see if they can replicate or outdo it. The latter was a bit nondescript earlier. I have a feeling it’ll flip to an icon-esque outcome. We’ll know soon. 
Thanks all

Josh

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4808509

[Uncertainty]

On 16/02/2023 at 00:50, The Bevmeister said:

Hopefully this hasn’t been discussed/answered yet but, at what point would the models start to give any accuracy towards the UK following the SSW completing it’s course?

Bev I would say model agreement is actually already higher than average due to the ssw, take a look at the mean anomalies of the big 3 ensemble sets at 360(!) hours out…

EPS

GEPS

GEFS

I would hazard that the ssw is responsible for this agreement. The MO often state that a super strong OR super weak PV increases the general accuracy of trop forecasts. The above is testament to that.

Hope that helps and agree your question and others of new/learning/any members should be addressed to foster cohesion and togetherness on this thread.

Original post: https://community.netweather.tv/topic/98326-model-output-discussion-into-february/?do=findComment&comment=4808523