nick sussex

I can understand why you say that . The issue is the slow clearance of low pressure . Lows hanging around the UK slowly filling . The ECM at least tries to clear the low day 5 into 6 .

Not the best of starts to the day for coldies . Although some differences remain between the models . The ECM probably the best upto day 6 in that some tweaks could see colder conditions hang on for more of the UK . Day 10 scrapes some interest . The GFS tries to develop a more northerly flow later but low pressure remains parked over the UK slowly filling . Heights building into southern Greenland are poorly orientated . The pattern needs a large se correction . The UKMO nothing to write home about ! Earlier two chances for snow . The low moving in from the sw . Detail wise still some disagreements , more likely Wales n England , north Midlands towards the ne . A chance also that as the low clears east there could be some rain to snow for some other areas . Later Wednesday still some uncertainty as to how the next low moves in . This would in any case be likely to be a snow to rain event for the risk areas .

The GFS 06 hrs run tries but we don’t manage a clean ejection of the shortwave . We need a complete separation from the upstream mothership ! No hang back of energy . This is important . It will then promote heights circled yellow . This then adds forcing on the bottom low . This will alter the track into the UK .

There’s perhaps one opportunity to eject some shortwave energy east se and this would need to happen to extend the cold further and cause a domino effect on the future evolution . You can see the ICON similar to the others . They try to eject some shortwave energy off the main complex low upstream . The mechanics essentially the two lows will essentially spin anti clockwise as this happens because of some forcing from the ne some energy tries to head east se . You can see that shortwave . We don’t manage to eject that cleanly to run into France . This would further promote heights to the north . Its a longshot but realistically I don’t see any other opportunity within the day 5 timeframe .

An interesting start to the day with some changes to the upstream set up. The models are trying to send some energy se rather than spilling everything over the top to the ne . The change is more dramatic when you compare yesterday’s 00 hrs runs with today’s . The question is whether this trend can accelerate. If it does then the outlook can change quite markedly in the medium term . The ECM out shortly so hopefully that follows the new trend . Yesterdays UKMO 00hrs run to T144 hrs Today’s to T120 hrs . Note the upstream low aligning more nw se . The wedge of heights developing over southern Greenland towards Iceland . Original post: https://community.netweather.tv/topic/99584-model-output-discussion-into-winter/?do=findComment&comment=4966425

I’d be dubious of anything shown post day 5. The ECM is wildly different from last nights run . I doubt we’ve seen the last of the earlier changes . The models have only just latched onto that wedge to the north .

We still need more dig se of energy . At this point we extend the cold by a day which is a start . This new wedge of heights to the north which the models are developing , we’ll have to see how that plays out this evening . The upstream low is quite ferocious and we’d need some energy to disrupt off that .

An interesting start to the day with some changes to the upstream set up. The models are trying to send some energy se rather than spilling everything over the top to the ne . The change is more dramatic when you compare yesterday’s 00 hrs runs with today’s . The question is whether this trend can accelerate. If it does then the outlook can change quite markedly in the medium term . The ECM out shortly so hopefully that follows the new trend . Yesterdays UKMO 00hrs run to T144 hrs Today’s to T120 hrs . Note the upstream low aligning more nw se . The wedge of heights developing over southern Greenland towards Iceland .

No not in terms of a future easterly. It could have helped if other factors played ball .

The ECM develops the shortwave near Iberia and has a more favourable upstream low positioning at T96 hrs .

The ICON 12 hrs run certainly trending towards the ECM 06 hrs control run . The shortwave formation near Iberia stops a ridge from pushing ne . This looks to be the bellwether for increased chances of hanging onto the cold. Original post: https://community.netweather.tv/topic/99584-model-output-discussion-into-winter/?do=findComment&comment=4965697

The ICON 12 hrs run certainly trending towards the ECM 06 hrs control run . The shortwave formation near Iberia stops a ridge from pushing ne . This looks to be the bellwether for increased chances of hanging onto the cold.

It’s developing a shortwave near Iberia . This might end up a better run .

There really is very little difference in the overall set up between the ECM 06 hrs control run and the 00hrs op. Its a minor tweak which results in the cold extension at T144 hrs . All will be revealed soon .

The last week has highlighted the inability of the models to deal with shortwaves . The ECM mean shows good support for the shallower low further south . The UKMO fax charts look like old news already .

The two lows upstream are likely to phase at day 5 . We really need to see some shortwave energy sent se as that happens . Will the ECM manage it .

The ECM at T72 hrs with a shallower low further south .

No support so far this morning for last nights ECM solution from the GFS , UKMO or ICON . The cold lasts into Tuesday for most of the UK . Still some disagreements re the first low track . The GEM has a little more trough disruption and tries to cut some shortwave energy se . I would be surprised if the ECM maintained its evolution from last night but hope springs eternal !

Interesting ! Only one run and we’d need to see westwards corrections . Should keep this thread busy with the ECM dangling the possible easterly tease !

ECM backtracking at T72 hrs . Weaker low further south than the 00hrs .

The GEM with more changes upstream . The models seem unable to decide what happens there .

The GFS issue is the orientation of the low not so much its northerly track . The early timeframe is crucial in determining whether the cold air remains in situ or whether the first low lifts most of that out . This would then impact any second low .

That’s yesterday’s chart .

Arpege has dropped the first low further south . Quite a big change between its T102 hrs 00 hrs run v it’s T90 hrs 12 hrs run .

There was some support for the ICON view of things in the 00hrs Mogreps . A lot depends on the track of the first low.