Model Output Discussion - Spring Has Sprung

[damianslaw]

 nick sussex Like a long snake.. we do seem to see these features more than we used to, aligned to the 548 dam line. 

[LRD]

8 minutes ago, nick sussex said:

I don’t think I’ve ever seen a warm front this long before .

[Rain All Night]

8 hours ago, RainAllNight said:

0z/6z ensemble means, Thu 1st to Fri 16th (day 15)

The ensembles are still broadly following the script we've established over the past few days: high pressure dominating to the south initially and deflecting the northerly blast around 6th Feb, then a large low pressure system crossing over the UK from roughly 8th to 12th Feb, and thereafter, late in the run, we still have the height rise signal, which appears to be focused just slightly to the west of us (especially if you ask the GEM), which might give it a colder flavour - but equally, it could simply indicate the eventual return of the Azores high.

0z/6z deterministic runs, Thu 8th (day 7)

Just a few of the individual ideas for a week from today, when the large (and growing) low pressure system is expected to break through from the west, heralding the start of our change in weather pattern.

12z ensemble means, Fri 2nd to Fri 16th (day 15)

ECM briefly gives us a mean northerly over the UK on 10th/11th Feb. I've noticed that these means are all showing the big low clearing away from us a little more quickly than had previously been suggested - it now looks likely that we will be out of its influence by Monday 12th Feb. The height rises that follow soon after it departs are really rather striking, particularly on the GEM, and though they may amount to nothing more than an Azores high extension over the UK, there is scope at this range for this signal to result in something altogether more interesting. Either way, it doesn't look like we need to brace ourselves for any more than about four or so days of wet weather late next week.

12z deterministic runs, Thu 8th (day 7)

I'll show a broad selection of models this evening, since some of them are showing snow events at this timeframe.

Edited February 1 by RainAllNight

[blizzard81]

Heights over southern Europe aren't as low on the latest EC46 throughout so that's a downgrade imo. We need something at least semi-special to rescue this uneventful winter. The lessening of the lower heights to our south during Feb does not aid our cause. 

[minus10]

Like the Gefs, the Eps showing clear signal for the trough also..

..uncertainty after but a general rise in pressure..

..solid dip in 850s also ..

...however on the rise later in the run  but as Mike showed on the clusters large uncertainty by then..

...so a cold trough looks a good bet..how cold and type of precipitation and location still to be decided...

[Lukesluckybunch]

I'm hoping the models will give more of a solid cold outlook in the next few days..if they do then 4am starts will be back for me!haha

[LRD]

 blizzard81 Nowt to worry about at this stage, though. Detail will change. EC46 has been rock solid on this for a while now. If, IF, we get cold from around the 12th/13th/14th it'll be a big win for the model

Temp anomalies are lower than average from week of 12th to the end of the month

[sebastiaan1973]

 LRD indeed, a couple of runs with cold anomaly for NW-Europe.

[Lukesluckybunch]

9 minutes ago, sebastiaan1973 said:

indeed, a couple of runs with cold anomaly for NW-Europe.

Looking at them charts would probably indicate below average temperatures,but nothing especially cold and snowy..the hp looks to close to the uk!the worst of the cold reserved for central and eastern Europe..anyway let's see how it goes

Edited February 1 by Lukesluckybunch
Adding

[Ali1977]

Looking great fir the north late next week, hopefully then better further south by the weekend as the cold digs south 

[Ali1977]

3 days of constant snow on this run for the north no doubt it’ll move about over the next few days but good to see the possibilities 

[CoventryWeather]

Putting the prediction in now - that low will continue to move south over the coming days.. 

Mid week slider feature has seen a trend south today - wouldn't be surprised to see the later low shift south too. Somewhere could get quite the snow event next week. 

Interesting times ahead.

Edited February 1 by CoventryWeather

[Mike Poole]

GFS is able to bring in an easterly T246:

Initial cold plunge delayed a little on this run compared to 12z, but an interesting evolution so far afterwards.  There are quire a lot of options for a cold evolution beyond day 9, I think.

[Ali1977]

T144 mean, that low sinking south quite a lot at such short range - I expect the south will be in the action on many ENS  into the weekend 

Edited February 1 by Ali1977

[bluearmy]

 Ali1977 needs to a fair way further south than though - does the ridge to our south have anywhere to go ? 

[Ice Day]

An excellent day 8.5 mean from the GEFS

 

Tomorrow promises to be another interesting day of model-watching.  

[bryan629]

Well this is all very interesting, 

looks like a massive hit on the PV to me 

Definately easterly winds here

 

Signs of a split going on lower down as well ... GFS control 12z showed that up nicely!! 

 

 

Edited February 1 by bryan629

[WYorksWeather]

ECM ensembles starting to firm up on an interesting pattern. Looks like a delayed double push. The initial attempt to push the cold through fails on around the 7th and only reaches into northern England. The second push is then more successful for the south around the 10th. There are some outliers that either fail to push the cold at all, or have the first push succeed for the south, but those scenarios now look less likely.

As we approach mid-month, a huge amount of variation. By T+360 you have ensembles reaching up above 10C at 850hPa and below -10C. The mean shows a reversion to average conditions, but that doesn't really tell the full story.

The meteogram for Reading below clearly shows the uncertainty by mid-month - plenty of ensembles that want to keep things cold in a northerly airflow, but plenty that restore the south-westerly flow.

In short, some sort of cold spell looks likely. Key uncertainties at this stage are around depth of cold (will it be cold enough for widespread snow?) and duration (a few days then a return to mild, or something more prolonged like we saw in January?).

Lots still to unravel, but enough here for some interest.

 

[damianslaw]

I sense we may have a far more active spell on the way in this thread compared to the last 10-12 days or so, especially as its Friday tomorrow and weekend thereafter. An interesting few days ahead. If the models have the timings correct expect by Sunday for them to all hone in together when such changes to a colder evolution are likely. 

Edited February 1 by damianslaw

[SLEETY]

Gfs was one of the mildest runs so obviously struggling with the set up in a week's time, some ensembles bring the colder air South quicker than the op. 

Lots to look forward to in a weeks time onwards.. 

[northwestsnow]

ICON

[Kentspur]

 northwestsnow Promising start to the day slider moving across Wales and the south& looks likely Midlands/EA if it went on further and further north surely too

Edited February 2 by Kentspur

[SLEETY]

These lows always end further south in reality remember the last fiasco in January missed the uk completely and hit France instead

[northwestsnow]

GFS/GEM ️

UKMO No thanks

GFS

180

Edited February 2 by northwestsnow

[feb1991blizzard]

GFS 0z is a stonker.