Model Output Discussion - Spring Has Sprung

[Lukesluckybunch]

Just now, January Snowstorm said:

s aside it all begins in the reliable timefrane

Do you think so...it didn't get going until day 8 I thought

[January Snowstorm]

 Lukesluckybunch yes but the building blocks across all suites are there at day 5. Some sort of Easterly is odds on I think. Whats uncertain is will be a mild Southeasterly or a bitter Northeasterly.

I've a good feeling about this one, as ever time will tell  

Edited March 2 by January Snowstorm

[Lukesluckybunch]

Just now, January Snowstorm said:

I've a good feeling about this one, ad ever time will tell  

The ecm ended brilliantly!

[damianslaw]

All a long way off, but ECM going for a full long draw easterly by 11/12th. I remember the snowy 12th in 1996 and 2006, indeed second week in March has often delivered a cold snowy punch. Lets see if it holds firm with this idea. GFS less keen making more of low pressure to our SW positioned wrong for colder uppers. What is becoming quite clear is our first scandi high of the season, rather late for some, but on its way and very normal for March. 

[Met4Cast]

 Metwatch 

I don’t think using the BFTE, which was one of the most extreme SSW responses on record is really a fair comparison. 

The continent warms very quickly through March (typically), direct northerlies are often a much stronger source of cold by late March/April. 

[January Snowstorm]

Nothing unusual on timing of course. As racing fans will know, many a Cheltenham has been run off under bitterly cold conditions and even snow. For me the critical thing about snow in March is it must happen before mid month!

[Lukesluckybunch]

4 minutes ago, January Snowstorm said:

Nothing unusual on timing of course. As racing fans will know, many a Cheltenham has been run off under bitterly cold conditions and even snow. For me the critical thing about snow in March is it must happen before mid month!

I agree with all that your saying facts..hasn't there also been times when it snowed in april..though I would think,it would be very hard for it too settle at that point

[Metwatch]

13 minutes ago, Met4Cast said:

I don’t think using the BFTE, which was one of the most extreme SSW responses on record is really a fair comparison. 

That is why I used several examples, and we still have an SSW on the way, which we don't fully know what the response will be yet. Yes northerlies can be quite cold, but it's not the coldest direction by early spring. North easterly sourced airmass from Scandinavia can still be pretty cold even into April. Happy to be proven wrong if you can show me a few examples of a colder direct northerly in March or early to mid April

Edited March 2 by Metwatch

[phil nw.]

We can see that quite early on there is disagreement wrt  the orientation of a Scandinavian high.This will influence the chance of any deeper cold pools coming this way.

UKMO looks the best for that in the coming week with a visit of -8c uppers from day 5 across the uk with a chance of some snowfall.

Chasing these cold pools is always liable to disappointment as a small shift in the pattern will change these at short notice.Still it looks the better outlook for coldies currently as the cold feed is quite a decent fetch from around the high from northern Scandinavia/Russia,the coldest source. 

On the other models the main thrust of cold heads down into Europe further east  in week 1 until we see signs of retrogression in week 2 .ECM by day 10 bringing a cold north easterly--possible as the pv continues to weaken but as we know it's day 10 again.

We will have to see if the uk model is on it's own with the colder outlook next week but after this i will be hoping for some brighter and drier weather with a bit of a warmup.

 

[January Snowstorm]

 Lukesluckybunch

Snow in April is useless really, gone in 30mins. Whereas early March under the right conditions it can last a,day or 2

[nick sussex]

The ECM does bring some interest after a shaky start .

It did drop the ball between day 3 and 4 where it has the more progressive upstream trough .

This then means any cold pool gets thrown nw . The differences between the ECM and UKMO highlight the impact of relatively small changes in the depth and track of any cold pool .

Later the ECM tries to salvage affairs with the low trying to track ne and some colder pooling to the ne heading sw . 

 

[stodge]

Evening all

Another fascinating batch of 12Z output. To be fair, far from all  the models are in the "cold" camp - JMA being a good example.

The key seems to be getting the Scandinavian HP to orient west and then north west to set up a more direct E'ly feed which in turn encourages the Atlantic trough to move into Europe and offer "interest" and "potential" to southern areas.

We're a long way from getting the detail of next weekend resolved - we will have an LP close to the south west on Monday and the first manifestation of the strengthening Scandinavian block will be a shift to a SE'ly air flow (still mild) while the trough seeks a way under the evolving block from midweek onward. The risk comes if the trough fails to get into Europe before pressure rises over Iberia which would maintain the SW flow - it is a risk and not one to ignore.

[sunnijim]

.....A few of still hanging around in the nightclub after last orders hoping that there might just be hope of taking some eye candy home at the 11th hour before the doors close on yet another fruitless chase.

# March model discussion

#Winter 23/24

#90sSaturday nights.

[January Snowstorm]

 sunnijim 90s Saturday nights out!!! Now thats what I call living!! ..... and snow watch beeb for Sunday!

I'm quietly confident with ukmo, ecm and gfs all singing an Easterly tune

Edited March 2 by January Snowstorm

[baddie]

 Metwatch Easterlies could also bring in wall-to-wall sunshine e.g late-Feb 2021 and late-March 2020

[Mike Poole]

ECM op well supported in the clusters T192-T240:

It’s cluster 2 with 18 members.  Fine margins with that high pressure to the north between the easterly and cluster 3 which has a southwesterly.  Cluster 1 looks a bit of a mess.

I still think the easterly may have some legs, it has shown for a while now, and like others have said, I think is has the potential to upgrade as the models factor in the details of the strat warming over the next week or so.  

[Met4Cast]

The det seems to fall off a cliff in terms of the cold pooling into the UK.

Synoptically the det is quite well supported but in terms of cold pool positioning etc, very little support.

[Uncertainty]

 Met4Cast there have been enough ops recently having a go at the cold pool to view it as a feasible option. However,  the blown up trough is probably more likely given recent form - we have really struggled to get lows to undercut in recent years. Need to see that cluster disappear and full model agreement to start even thinking about looking at the cold pool / dew points / precip intensity etc. The ecm op solution nearly goes belly up and then rescues it at day 9/10 - that’s light years away in modelling terms. The UKMO gets there quicker but I’m not convinced it would be particularly snowy.

 

There has been a shift in the forecast for beyond day 10 today, yesterday the models wanted to barrel the Atlantic back, today the high looks more resilient. Plenty of twists and turns to come but personally the excitement has ebbed away for me after the Jan / Feb forecast fiasco.

[Jordan S]

Ecmwf ties quite well synoptically with yesterday’s update, to be honest all models do for the most part. For northern areas yeah easterlies look possible from around 10-11th, but southern and southwest England again winds more southeast to eastsoutheast so cold rain at times with a drier trend afterwards still more likely and slightly milder temps generally here again with those lows over the south/southwest and France, at first keeping the weather largely unsettled during this beginning and middle part of the second week of March before slipping to our south, and relatively cold in the north, a few wintry showers possible at times here, perhaps slightly more than thought yesterday, but entirely normal for the time of year, colder upper air temperatures already in the north very slowly envelops the rest of the UK within a developing anticyclonic weather pattern over the UK towards mid month.

So the settled spell for most of the UK still favoured for 12-14th with models showing this clearly now in comparison to yesterday, any potential slightly colder than average 2m temperatures largely look to be the result from some colder nights that look to feature, daytimes may still feel rather pleasant, especially in the north with the odd snow shower here.
 

Slightly beyond mid month unsettled weather does look as thought it previous post yesterday like probably returning for all, temperatures are more uncertain than yesterday I think, due to slight uncertainty with position of the high to our north and over country, I would say weakening heights to our north and over the UK and clash of much colder air moving south or southwest from north/northeast and rather warmer than average air moving up from the south/southwest from over southwestern Europe looks again more likely though with approaching lows to our southwest once again. That heightens snow interest still for north especially with frontal systems moving northeast, so this is rather similar overall to my update previously.

Edited March 2 by Jordan S

[ANYWEATHER]

So the Hadley Cell is getting bigger?  Can't see the Azores high..

Edited March 2 by ANYWEATHER

[Daniel*]

Mid March doing something which none of winter could muster on GFS 18z. Thats a full house of det runs now GFS/ECM/UKMO showing potential for deeper cold air from east to arrive in the second week of March. 

Edited March 2 by Daniel*

[nobble]

 January Snowstorm or in 2013 it lasted 3 weeks !

[Rain All Night]

On 01/03/2024 at 09:15, Rain All Night said:

0z deterministic runs, out to Fri 8th (day 7)

Since everyone else is focusing on cold... dry spell probably looking good.

0z ensemble means, out to Sat 16th (day 15)

Looks like the Atlantic could be held at bay for at least a week... would be much appreciated.

12z deterministic runs, out to Sat 9th (day 7)

Note the new (to Meteociel) addition here - the ECMWF machine learning model, AIFS.

12z ensemble means, out to Sun 17th (day 15)

It's been 36 hours since I posted the outputs, and what I see now is that we're left with the impression from the ensemble means that the high-latitude block will collapse from about 13th March - I think @Met4Cast has been predicting that. However, the subsequent signal is for a mid-latitude block, so all is not lost in the dryness stakes.

Edited March 2 by Rain All Night

[WYorksWeather]

Up to T+240 at least, the GFS 18z ensembles show that the GFS OP is a cold outlier. I'm not going to be convinced that any proper cold is on the way until we see more than an odd run or two in the ensemble pick up on it.

[Mark wheeler]

 January Snowstorm wow without reading on , this seems some rant from yourself.