mulzy

Day 7 is an eternity as far as precipitation is concerned. The track of the low is yet to be confirmed - let's see the spread in the ensembles. ECM is a very good run with the the Midlands / North getting hammered with snow.

Good ECM run - from a selfish point of view I hope the tracks of the lows are 100 miles to the south but those kinds of details are not worth discussing at days 8,9 and 10. The key is the solution between days 5-7. It's almost as good as the UKMO.

Indeed. This chart represents the risk perfectly.

The UKMO is the best solution at day 6. We do not want too much westward momentum of the low heights to the north. That will lead to SW formation that may cut off the cold air.

Snow flurries here in Raynes Park. 3C and breezy. It's bitter out there!

Indeed it is - but it is a mess of shortwaves and wedges. Let's hope for a cleaner evolution on the 12z. Potential for a snow event at day 10 in the south?

Disappointing ECM at day 6. Heights into Greenland are not as high as the other models and that shortwave to the west of Iceland causing issues as are the heights over Iberia.

The Met Office Extended forecast matches these MOGREPS stamps at day 8. Very positive in my opinion.

Add MOGREPS to that list. Solid indications it will turn colder day 8 and beyond.

FWIW, GEM shows centre of High close to Iceland.

Pretty underwhelming output this morning. Not a fan of the UKMO-GM run this morning! Can ECM save the day?

3.0C and 76mm please

Stamps at day 7. Wide variety of solutions on offer but I guess it averages out at a UK Hugh.

The lack of positive tilt at day 5 on the ECM was the clincher. Once we had crossed that hurdle, the rest followed. All other models except ICON has a positive tilt so caveat emptor.

Not as good as this morning's run for sure. Let's hope it's a blip. Still a decent setup but a downgrade sadly.

Good morning and happy new year folks. As the 6z has shown, GFS rarely makes big moves but rather baby steps in backtracking. This is likely to continue on its 12z run.

Day 8 MOGREPS stamps. A UK High is the favoured solution, but other interesting solutions on offer…

As soon as ECM day 5 turned up as is, it was obvious that the UK High would be the next solution. Let's see where it sits in the ensembles suite but the UK High is not a shock as it has been trending this way for a while now. Let's hope the UKMO-GM can pull off a major coup!

It's not as good as the UKMO-GM day 5 chart sadly. Let's see where this leads but UK High is probably the favourite.

ECM day 6/7 is decent. How the energy distributes itself with regards that low on the Atlantic will be key. We need some energy going under or else that high will sink.

Still lots to be resolved - see MOGREPS Stamps from the 6z run for 198 hrs. Multiple solutions on show which have been seen in various NWP output over the last day or two.

Remember the GFS rarely backtracks in one iteration. It takes small baby steps and hopes no one is looking.

Just looking at the Operational runs, there is a significant difference by day 6. ECM, UKMO, and ICON are the most similar - although there are differences between them. UKMO doesn't have the pool of low heights over the Baltics whereas the ECM and ICON do. The Atlantic profile of the UMO and ECM is very similar. GEM is very different - the low in the Atlantic is close to phasing with the low close to the British Isles. In subsequent timeframes, it does phase - I don't think we want that to happen. The GFS has this spoiler low to the west of the southern tip of Greenland - no other model has this. Still a lot to resolve but good to see the ECM and UMKO-GM broadly similar at day 6. Original post: https://community.netweather.tv/topic/99584-model-output-discussion-into-winter/?do=findComment&comment=4987612

Just looking at the Operational runs, there is a significant difference by day 6. ECM, UKMO, and ICON are the most similar - although there are differences between them. UKMO doesn't have the pool of low heights over the Baltics whereas the ECM and ICON do. The Atlantic profile of the UMO and ECM is very similar. GEM is very different - the low in the Atlantic is close to phasing with the low close to the British Isles. In subsequent timeframes, it does phase - I don't think we want that to happen. The GFS has this spoiler low to the west of the southern tip of Greenland - no other model has this. Still a lot to resolve but good to see the ECM and UMKO-GM broadly similar at day 6.

For wintry synoptics, the reliable is generally up to date 4 (96 hours) and the age-old rule, "if the UKMO-GM is not showing it, be very worried".