nick sussex

I wouldn’t be relying on an Arctic high to push the troughing south . They’re notoriously difficulty to model. So at the moment there’s still uncertainty as to what will happen in the medium term . I don’t take the outputs at face value and always factor in margin for error. Looking out for where things can go wrong and not expecting everything to run smoothly seems a good way to approach UK winter synoptics.

Still prefer the UKMO . A much cleaner evolution . The rest have the shortwave at T168 hrs and this far out that could still prove troublesome if there’s too much of a sw track . Even if the UKMO develops a shortwave into day 8 the profile to the north is likely to take that further se . The pattern on the rest needs a se adjustment , you want the instability but don’t want a cyclonic flow sitting over the UK.

The UKMO hits no 1 spot pushing the GEM into second and the GFS into 3rd spot . The UKMO takes the coveted top spot because it’s less likely to have the blocking moving nw post day 7 . The GEM brings the shortwave sw and even though it just about manages to deliver some interest , it’s not a trend that has much margin for error . The GFS does similar but struggles more to the get the cold south . Both the GFS and GEM follow a similar pattern to last nights ECM . This shortwave needn’t be a major drama maker if it heads more south . We don’t want the sw track . It’s likely to phase with low pressure in the Atlantic so the phase point needs to be further east otherwise you run the risk of the phasing developing a deeper low and this pushing ne to the sw . This will lead to a mild encroachment. And it could push high pressure ne from the sw ahead of it. Anyhow that’s some way away in terms of timeframe. Let’s see what the ECM has to say on the matter !

The UKV has -13 850 hitting the se coast . We’ve had many past winters and not seen that sort of value . It’s a shame we don’t have much instability to work with .

The latest UKMO fax chart for midday tomorrow shows a trough in the far se and a convergence zone along the Channel. The ECM having been one of the least cold easterly solutions now completes it’s full u-turn showing -12 850 just off the Kent coast at midday tomorrow .

Thank heavens I’m not due to fly back tomorrow ! I can only imagine the chaos when Flurrygate hits ! I think it’s a nowcast , could be better or worse than current predictions.

Talk about an emotional rollercoaster for coldies . So far so good this evening even though the GFS wanted to take a Mystery Tour ! The ECM out soon and I can sense the trepidation rising ! We did see an improved 06 hrs control run to T144 hrs from it earlier so let’s hope that’s a sign it’s turned a corner ! We live in hope !

Let’s hope we can keep this more positive momentum into the next runs . Theres been some short term upgrades in terms of tomorrow for those lucky enough to be in the se and we’ve seen a better ECM control run to T144 hrs .

Interestingly the UKMO warning is for 4 am to 10 am and that’s before the coldest 850s arrive . At that point it will be a case of seeing how much convection can happen without the help of the convergence zone . Certainly I think it’s best to keep expectations low and then just see what happens .

The UKMO fax chart for tomorrow at 6 am shows a convergence zone over the far se . This is the likely reason for the warning as this will help convection .

It’s really thanks to the depth of cold . At the moment it looks like we’ve squeezed out the most possible from that cold pool . Now a wait and see . There isn’t a lot of instability but quite a large temp differential between the 850s and sea temps will help .

Yes . The two areas mentioned in their discussion have a large impact on what happens re any northerly here . Uncertainty in the east Pacific is related to what happens with that Pacific Ridge and we’ve seen the knock on effects especially in terms of the ECM output . The amplitude of the pattern over the USA and Canada effects the building of any Greenland or North Atlantic high . For this reason I’d not be too downbeat over cold prospects just yet . More runs are needed ! We just don’t know what the correct evolution is yet .

Especially pertinent to Europe given we have the uncertainty over the Pacific Ridge from the north and any blocking towards Greenland which is impacted by the amplitude in the USA and Canada . This from the latest NCEP extended forecast discussion. For the next system developing across the southern Plains Friday, the GFS is slower and more amplified with the upper trough compared to the much more progressive ECMWF/CMC, and therefore considerable timing differences with the surface low track (GFS slowest and ECMWF fastest by Friday night). Both the EC and GEFS ensemble means are between these two solutions, and therefore these served as a good proxy for the expected location of the surface low. Model spread becomes high across the eastern Pacific and adjacent portions of the West going into next weekend, and this leads to below average confidence for that region. The ensemble means accounted for 40-60% of the forecast blend going into next weekend to account for the growing model differences. Original post: https://community.netweather.tv/topic/99706-model-output-discussion-into-2024/?do=findComment&comment=4998980

The main risk for any showers should be as the coldest 850s start crossing the southern North Sea . Theres not much instability available that’s why it’s important to squeeze the coldest possible 850s out of that cold pool moving west . I think it will really come down to a nowcast situation.

The ICON EU 03 hrs run to T30 hrs shows a slight increase in the precip towards the se . Also a slight northwards adjustment in the -10 850 cold pool.

Especially pertinent to Europe given we have the uncertainty over the Pacific Ridge from the north and any blocking towards Greenland which is impacted by the amplitude in the USA and Canada . This from the latest NCEP extended forecast discussion. For the next system developing across the southern Plains Friday, the GFS is slower and more amplified with the upper trough compared to the much more progressive ECMWF/CMC, and therefore considerable timing differences with the surface low track (GFS slowest and ECMWF fastest by Friday night). Both the EC and GEFS ensemble means are between these two solutions, and therefore these served as a good proxy for the expected location of the surface low. Model spread becomes high across the eastern Pacific and adjacent portions of the West going into next weekend, and this leads to below average confidence for that region. The ensemble means accounted for 40-60% of the forecast blend going into next weekend to account for the growing model differences.

We should bear in mind and something often highlighted in the NCEP extended forecast discussions . The ne Pacific area has a large drop in observational data .

The Pacific Ridge is causing issues and the ECM seems unable to decide how much impact that will have . It is at least an improvement on last nights run so reasons to be cheerful . Earlier it’s also expanded the area of -10 850s moving westwards . It took its time , hardly been a good few days for it !

This cold pool from the east still isn’t settled . Still some differences with the UKV 3pm showing a much larger area of sub -10 air with -12 and -13 just off the se coast . The others do show -10 850 values but a generally much smaller size cold pool.

The GFS 06 hrs run is a good illustration in that sometimes smaller is better ! A little high centred to the nw n with cold n ne flow funneling sw can provide what coldies want .

Amen , the GFS 06 hrs didn’t follow the misery model . Nice little mini Omega block .

You’re in denial ! Lol Anyway let’s hope it’s just thrown out a rogue run .

No amount of spin can save the ECM op. So it starts the day by grinching out on the easterly and then adds insult to injury . Can we just nuke it from orbit !

It hasn’t , it’s awful at day 8 . Trouble started brewing at day 6 .

The ECM looks like it’s going to throw a downer on proceedings . Not liking its day 7 at all .