Model Output Discussion - Spring Has Sprung

[sebastiaan1973]

Thanks. The windplume is clear. I guess we have to wait for the periode after the 10th of february. 

[mulzy]

No real change - nothing cold in the NWP currently.  The EPS has gone backwards sadly.  Hope and the outer reaches of the MetOffice forecast are keeping us just about in the game.  But the clock is ticking and the medium term story could be record breaking warmth / mildness to bring in February.

Edited January 25 by mulzy

[Rain All Night]

7 hours ago, RainAllNight said:

0z deterministic runs, Thu 25th to Thu 1st

The end of the GEM is quite different to the others, with the low that forms over the Atlantic on Sunday flying upwards and kicking up a little high over Norway and Sweden.

0z ensemble means, Thu 1st to Thu 8th

We almost see some interest around days 10-12 (Sun 4th & Mon 5th) on the ECM, perhaps a hint that a brief ridge could build in from the west, after the PV clears back out of northeast Europe. It doesn't show so much on the other two models.

12z deterministic runs, Fri 26th to Thu 1st

The GEM again takes a different path, but still ends up at the same destination for the UK: high pressure tucking us in from the south.

12z ensemble means, Fri 26th to Thu 8th

We could see some brief interest from the northwest around 3rd/4th Feb, by the looks of it. Right at the end there, it looks like the Atlantic trough might begin to flatten up, making our winds more westerly than southwesterly, and the ECM might even be said to be looking rather stormy again by day 14.

[WYorksWeather]

Quite a marked divergence tonight between the GFS and ECM ensemble suites.

Regardless of where you are in the country, ECM is extremely bullish about the idea of mild conditions prevailing well into February, with at most a couple of temporary spells closer to average. GFS is not exactly supportive of the idea of cold, but it is more open to the possibility.

Spread increases markedly as early as the end of the month, so it would appear that some sort of signal is being detected around that time from these charts, that pulls the models in one direction or another. Here are the means at day 6 - not a lot in it except the Azores high influence slips a little bit further south and west on the GFS compared to the ECM.

By day 8, the divergence is a little more obvious - the low over Scandinavia is slightly less deep on the GFS, and there is a bit more of a tendency to try to build heights over Greenland, which should at least initially begin to turn the wind direction a little bit north of west, and likely bring us something at least more seasonal if not necessarily overly cold.

We can see where the uncertainties are on the spread chart at day 8. Both models agree that there is a great deal of uncertainty in the pattern over Greenland and Northern Europe. Unfortunately, it doesn't look like the Iberian high is going anywhere at least up to this point.

The ECM site is down, so no meteogram this evening until it comes back up.

The key to watch for impacts on our vicinity will be which model comes out on top in resolving the micro details over Greenland and Scandinavia as we start February. That seems to be the key to getting even a temporary cold incursion given the heights over Iberia.

 

 

 

[Jordan S]

A much quieter period of weather for many compared with recently, Staying fairly unsettled still though for Scotland in particular though not as much as recently over the next few days with some very windy weather over the weekend for the western isles and northern isles of Scotland, gales with gusts to 50-60mph possible later tomorrow into Saturday as well as on Sunday with showers from the west then southwest into these areas.

Whereas further south over England and Wales and on the whole much drier and calmer, and this looks to be the case for much of next week, but some mostly lighter rain on occasion in places more likely to be in a few areas in the west possibly from a disturbance or weakening low pressure and perhaps becoming absorbed within higher pressure early next week. Best chance of lengthy dry and at times sunnier weather being in eastern and southeastern areas of England. 

By around midweek next week, winds becoming very strong over western isles and northern isles once again though gusts could reach 70mph for a time as a developing low pressure system travels northeast to our north.

Temperatures probably above average at times further south for the first half of next week, though perhaps trending slightly colder later next week in the north with wintry showers for Scotland..

Into the following week and more unsettled conditions look more likely to return to most or all with lowering temperatures with the risk of more significant snow returning to Scotland and possibly higher ground in northern England. 
 

Edited January 25 by Jordan S

[Cambrian]

I like the look of the 12z GEM op. It’s doing what we’re seeing a lot of the models do at the moment, in the splitting of the PV from Siberia through to Canada by day 3 or 4, the two lobes heading to the Bering Sea and Greenland, followed hot on its heels by the subsequent split of the Greenland lobe, with a chunk being imparted to the Barents Sea by day 5.

It’s then it gets really interesting though, from day 5 to 10, the Greenland lobe becoming much depleted as it donates successive low pressure systems eastward through Iceland to the Norwegian Sea to phase with the spiralling eastern lobe now over Scandinavia, 

the path of each transferring low just a little bit further south, leaving the door open to a potential swipe to the UK and Ireland and an incursion from the north.

The heights anomalies simplify the process beautifully, the European heights being drawn north through Scandinavia to the Arctic by day 6 or 7, followed by a brief attempt at establishing an Atlantic ridge edging into Iberia before those heights too are drawn north.

While not bringing the prospect for now of a sustained cold spell, the machinations of the PV and the waves of northward transfer of these heights are producing a useful outcome in heralding the end of the period of high west to east mobility through the Atlantic and Europe. A really enjoyable run. 

[WYorksWeather]

As someone mentioned above, and after the 23rd January achieved a date record, my attention naturally now turns to whether we might see any more. At the moment, probably the best chance within the semi-reliable would come between 1st-3rd February, depending on exactly when the warmest airmasses reach the UK, and whether surface conditions are right.

The date records for the 1st-3rd are respectively 16.1C, 16.1C, and 17.0C. All of those are reasonably achievable.

As an indicative guide, any chart showing maxima equal to or greater than 14C is a potential record-breaker for the 1st and 2nd, and 15C for the 3rd, given typical under-reading at the relatively coarse scale of the models.

Here is the latest GFS ensemble chart for the 1st, 2nd and 3rd:

  

At the moment, the best chance for a date record looks to be on the 1st, with a reasonable chance on the 2nd but only a very small chance on the 3rd.

Worth keeping an eye on, as small changes now may alter which day sees the warmest temperatures, and also the probability of a record. Even a 1C or 2C increase would take these records from possibilities to near certainties.

I will use UKV to have a look at the possibilities as the days in question come into range, but that's still a few days away. Just worth flagging at this stage.

 

 

[Mike Poole]

An oddity from the 46 dayer tonight, from the regimes plot:

On Monday 29th January, all members have no regime!  Does this mean we aren’t getting any weather?

More likely, the algorithm has given up the ghost for some reason!

[northwestsnow]

There really isn't much to be optimistic about ..

Even EC 46 looks meh.

 

[Eagle Eye]

A sudden wave of despondency in here again with the EPS, still looking towards the 2nd week of February for any potential but phase 7 MJO and high built-up momentum appears possible by then. Said all that needs to be said for now already.

[Metwatch]

35 minutes ago, Mike Poole said:

On Monday 29th January, all members have no regime!  Does this mean we aren’t getting any weather?

More likely, the algorithm has given up the ghost for some reason!

Probably getting confused by these lows around Azores and another one which comes up from the Bay of Biscay. Even to my eye it looks weird.

 

The GFS almost has a Spanish plume looking chart with that cut off low to the west of Iberia. Probably would deliver another 40C if everything came together in the height of summer with the placement of that low.

Infact comparing it with 18th July 2022, almost in an exact same position, I find it hilarious for some reason. That's an 'if only it was summer' chart if i've ever seen one in the depths of winter

 

Edited January 25 by Metwatch

[Rain All Night]

24 minutes ago, Mike Poole said:

An oddity from the 46 dayer tonight, from the regimes plot:

On Monday 29th January, all members have no regime!  Does this mean we aren’t getting any weather?

More likely, the algorithm has given up the ghost for some reason!

The pressure pattern over the Atlantic is pretty odd on that day:

[bluearmy]

  @Mike Poole yesterday was similar for a few days around the 29th aswell. 
seems an oddity about the model - perhaps due to the large number of members ??

[Don]

8 minutes ago, northwestsnow said:

Even EC 46 looks meh.

I thought week 19-26 looks a bit better this evening.  That said, high pressure over north Africa is showing it's ugly head!  The following week not looking as good though.

8 minutes ago, Metwatch said:

Infact comparing it with 18th July 2022, almost in an exact same position, I find it hilarious for some reason.

Potential for 20C?! 

I most certainly don't find it hilarious! 

[Metwatch]

10 minutes ago, Don said:

Potential for 20C?! 

I most certainly don't find it hilarious! 

The airmass is certainly warm enough for it had this been in March, but with the winds too weak at the surface to mix the airmass to a greater degree lower down, and still barely any strength with the sun, it will probably just be another mild ish day, maybe 11-12C in the south. Borefest!

We do seem to be continuing the theme from last year of having patterns the wrong way round and at the wrong time of year!

Edited January 25 by Metwatch

[joggs]

  @Dennis cmon Dennis,all you post is cold outlooks from lesser signs. How about a little fairness?.

Tia

[WYorksWeather]

15 minutes ago, Metwatch said:

The airmass is certainly warm enough for it had this been in March, but with the winds too weak at the surface to mix the airmass to a greater degree lower down, and still barely any strength with the sun, it will probably just be another mild ish day, maybe 11-12C in the south. Borefest!

We do seem to be continuing the theme from last year of having patterns the wrong way round and at the wrong time of year!

And generally, still not much movement on these meteograms. 

No wind direction without a W in it, temperatures above average every single day by day and night if you take the mean. Very much looks like February will start very mild, not withstanding any developments that may lead to a shot at cold later on.

We increasingly need to see something coming into view on the models by the end of the month.

In terms of possibilities of reaching 20C, I think the setups aren't quite aggressive enough. I think we need 10C or higher at 850hPa for that, coupled with ideal surface conditions, especially so early in February. It is theoretically possible, as I did see a 15C 850hPa on one of the ensembles in early December (which failed to verify, of course).

For comparison with the EC46, let's throw in CFSv2 for the next four weeks.

The mild signal does not really begin to fade until week 4 (15th-21st). Of course that doesn't preclude something showing up before then given the poor performance of the seasonal and sub-seasonal models, but the Met Office are also increasingly talking about second half of February.

If there is going to be any remaining interest, I think that's where we're going to be looking soon. This would also tie in with MJO reaching phase 7 in a couple of weeks, plus a lag beyond that.

[Metwatch]

17 minutes ago, WYorksWeather said:

If there is going to be any remaining interest, I think that's where we're going to be looking soon. This would also tie in with MJO reaching phase 7 in a couple of weeks, plus a lag beyond that

Pretty much a waiting game for the next week or 2. If somehow we could all be blocked from viewing models until next weekend, and then suddenly enable them, would be a lot better for our sanity!

[Don]

34 minutes ago, WYorksWeather said:

The mild signal does not really begin to fade until week 4 (15th-21st). Of course that doesn't preclude something showing up before then given the poor performance of the seasonal and sub-seasonal models, but the Met Office are also increasingly talking about second half of February.

Even that week looks pretty mild, although those temperature charts are to be taken with a dose of salt of course! 

Edited January 25 by Don

[WYorksWeather]

21 minutes ago, Don said:

Even that week looks pretty mild, although those temperature charts are to be taken with a dose of salt of course! 

Yep, it's still a little above average. Of course we should be aware that the signal for week 4 is usually weaker, so the model probably is more likely to just go with 'a little above average' as a default as it's the best bet in the long term.

I feel like we have what looks like a predictability barrier around day 7, so hopefully in the next few days we may be able to see deeper into February with a little more confidence.

[TillyS]

Dire stuff:

 

[IDO]

This is D16 on the GFS op, a run that follows the mean for a change:

GEM & GEFS mean:

 

The mean has been steady as a rock and continues to show a poor setup for cold as we head for mid-February. The same issues of mean Alaskan & Siberian High keeping the pattern locked in. The tPV is circulating Greenland to Scandi, ad finitum. 

Waiting for MJO and other background signals for a reset or forcing. 

Edited January 26 by IDO

[Harsh Climate]

  @TillyS

I'm a slight bit more optimistic this morning, Gfs throwing out a few nice runs now in the assembles. 

This for WestYorkshire doesn't look at all bad:  

Mid-Long range heading in right direction.

 

AO/NAO heading in right direction:

 .

 

With another Canadian warming underway (Which should tip things more in our favour and heading into the important part of an El Nino winter, I see February going only one way and that is Cold/Blocked and Potentially snowy!

Most indications are showing this to be mid February onwards but I'm hopeful we can sneak something in early February and get it going then. I would say no earlier than the 5th. 

 

I believe we will be jumping back on the chase next week fully, hopefully, earlier next week than later!

[Dennis]

3-5 febr we know more on this 

 

[Lukesluckybunch]

Ecm looking rather flat again this morning!little sign of any amplification