Downburst

Would like a take on this, from ECM site and the long range. 2M Temp Area average Northern Europe, to show where this is, a map A very large drop (Purple) in 2m temp compared to climate (Grey) for December showing there, purple box the middle tercile. This is opposite of the prediction last month which had December positive.. https://charts.ecmwf.int/products/seasonal_system5_climagrams_2mt?base_time=202312010000&index_type=Northern Europe And NOA negative for each of the 3 months to come. Although it has been negative nearly all year. But near -3 for February, which fits into expctations.

The ECM MJO for Day 10, the mean line is now above the COD area for phase 6, whereas yesterday and a few days before it flirted with below. So phase 6 period is adjusting and it it continues we might see more towards the end of the GFS runs at least and perhaps shortly the 10 day ECM. Remember the higher the amplitude the more skill the forecast has historically, so maybe once the next 5 days finish we might get more consistency. In saying all this, I am thinking, at least at the surface, that Canadian (+10c and corresponding Siberian -10 c temp anomaly this week is so strong, one has to wonder surely that will have more effect than anything else? Also, over the last few days the 10hpa anomaly over the pole has really strengthened each run for 1st week of January. Although I won't hazard a guess (mini ice age end of January ) how and when that might effect us, especially so far out from even happening, but that's a strong signal all the same.

Yes, world climate service is not related to any UN or intergovernmental org etc. but I looked up some info on Modoki EL Nino, can’t find a reliable comment as to what this might mean to these parts, so I’ll leave this from WIKI and that’s saying a lot if you follow Recent years when La Niña Modoki events occurred include 1973–1974, 1975–1976, 1983–1984, 1988–1989, 1998–1999, 2000–2001, 2008–2009, 2010–2011, and 2016–2017. and again wiki The first recorded El Niño that originated in the central Pacific and moved toward the east was in 1986.[77] Recent Central Pacific El Niños happened in 1986–87, 1991–92, 1994–95, 2002–03, 2004–05 and 2009–10.[78] Furthermore, there were "Modoki" events in 1957–59,[79] 1963–64, 1965–66, 1968–70, 1977–78 and 1979–80.[80][81] Some sources say that the El Niños of 2006-07 and 2014-16 were also Central Pacific El Niños impacts on Europe, El Niño's effects on Europe are controversial, complex and difficult to analyse, as it is one of several factors that influence the weather over the continent and other factors can overwhelm the signal Original post: https://community.netweather.tv/topic/99584-model-output-discussion-into-winter/?do=findComment&comment=4970099

Yes, world climate service is not related to any UN or intergovernmental org etc. but I looked up some info on Modoki EL Nino, can’t find a reliable comment as to what this might mean to these parts, so I’ll leave this from WIKI and that’s saying a lot if you follow Recent years when La Niña Modoki events occurred include 1973–1974, 1975–1976, 1983–1984, 1988–1989, 1998–1999, 2000–2001, 2008–2009, 2010–2011, and 2016–2017. and again wiki The first recorded El Niño that originated in the central Pacific and moved toward the east was in 1986.[77] Recent Central Pacific El Niños happened in 1986–87, 1991–92, 1994–95, 2002–03, 2004–05 and 2009–10.[78] Furthermore, there were "Modoki" events in 1957–59,[79] 1963–64, 1965–66, 1968–70, 1977–78 and 1979–80.[80][81] Some sources say that the El Niños of 2006-07 and 2014-16 were also Central Pacific El Niños impacts on Europe, El Niño's effects on Europe are controversial, complex and difficult to analyse, as it is one of several factors that influence the weather over the continent and other factors can overwhelm the signal

I tell you what. Looking a the spread of those MJO plots really tells you how hard more than 10 days forecasting is, if not borderline impossible to be honest thinking about it. If you can't get that very complex forecast correct, the the knock on effects given this etc and try to predict weather in North West Europe for 20 odd days ahead? I think it's a lesson to everyone to be conscious of that, not only do we not know what phase we will be in, we don't know the amplitude, all we have is the mean really and a good look at the spread making that mean. I'd be even more careful of this Phase 7 to 8 for end of month, it doesn't have to happen.

There is a paper here on the Skill of the MJO models. The briefest summary is if the initial condition is in high amplitude the resultant forecast skill increases. Also some data outlining the number of days each major model attempts to predict for. And some mad maths in there too if you are brave enough. journals To add, noaa produce verification for previous 7 and 15 days on their site most recent ECM, hard to make a call there, seems to me the mean is looking not amplified and the initial conditions show a strong starting point, hence increasing skill of the forecast. But not my area at all

Mid December and looking at the ECM 500 hpa anomaly, seems to me there’s a chance of blocking to the north west or north east. Plenty of interesting options. +NAO at 30% chance during this time, or glass half full way of expressing this is 70% chance of something else.

you won't need a coat, a jacket and umbrella will be fine

Yes and there is cold all over the northern hemisphere all winter, in many cases further south than here and yet the models aren't drastically wrong about that, so I can't see how the physics in the models doesn't account for it just because it's in north west europe, although I get the point, just not sure the models don't account for it. No hassle anyway.

You see it’s only a problem if you use the latest charts. Meanwhile yesterday using wetterzentral I was inadvertently looking at 24hr old ICON charts thinking my word that looks good compared to GFS. Gotten Himmel, for you ze 12z run is over.

Yes, well here we go, UKMO tells ICON you must be mad, southerlies are on the menu

To stop an active Jet or PV disruption? I suppose this is the start of the Canadian Warming perhaps. How's this for an anomaly at 10hpa

Basically the ICON take from the 00 run was for the first low to have a lot of energy The 12 z at the same time shows it not amounting to anything really

Yes, the warmest the 2m temps get at 156 ( 18z Wednesday), very chilly indeed still at that stage

Yes, further north is more behaved, Dublin for instance. I'd be looking at the mean here. And thanks @knocker for the reminder of looking at the expected conditions when looking at ensembles for a location to put the scatter into context, obvious but easily overlooked.

Summarise that perhaps, I had thought that migh5bwork. I use it in meetings and its ability to produce a summary is simply stunning, listens in and writes a summary at the end, almost magical. I’m sure it will be here sooner rather than later, the power of crowds etc.

Snow showers about. I’m in Dundalk and northerlies and north easterly never pay off due to a lot of mountains in the way north of me I’m afraid. But just picked up a new awd cupra formentor today so hoping to test the drifting even if it’s only heavy frost. Also, anyone recommend the very best pro re mappers? re no warranty issue.

Nice one mountain shadow, first of many I hope.

Mods, could you organise an AI to summarise every 5 to 10 pages when things are busy. Easy to parse the comments and ask for a summary. Might be interesting and possibly useful. Just a thought as it’s hard to keep up

Don't see areas south of Banbridge for instance getting above 0 Celsius on Friday. https://www.met.ie/full-screen-maps you can zoom in on the temps chart, very useful this as certain areas are locally more cold than the zoomed out chart shows.

Best I can see is Carlow and Armagh for Friday 03:00 am some wet snow and or snow. Have to try hard to see it but even very low probabilities might mean a surprise for someone, this is from the ECM site

OK, shameless attempt to get a short answer. Looking back at Enso states using Oceanic Niño Index (ONI) values and noting we went +0.5 April/May June and trying to find the last time following negative phase this occurred, if my eyes don't deceive me and ignoring MJO states, QBO and Indian Ocean and coupling of atmosphere etc. Winter 1972/1973. Anyone know what it was like? note the +0.5 will not end until at least end of Spring on recent predictions and in 1973 it ended same time, so very similar. Edit: asked chat gtp: Interesting he weather in the UK and Ireland during the winter of 1972-1973 was very cold, wet, and snowy. According to the Met Office, the winter was the coldest since 1962-1963, with a mean temperature of 1.8 °C, which is 2.4 °C below the long-term average1. The winter also had the highest snowfall since 1946-1947, with an average of 66 cm of snow across the UK1. Some of the notable weather events that occurred in this winter were: The Great Storm of 1972-1973, which affected the British Isles from December 28, 1972, to January 2, 1973. This storm brought strong winds, heavy rain, and coastal flooding to many parts of the UK and Ireland. The storm caused widespread damage, disruption, and deaths, especially in Scotland, where it was considered the most severe gale since 19271. The Big Freeze of January 1973, which lasted from January 8 to January 20, 1973. This was a period of exceptionally cold and snowy weather that affected the whole of the UK and Ireland. The mean maximum temperature for the month was 0.5 °C (6.9 °C below average) and the mean minimum was -2.7 °C (4.6 °C below average)1. Many places experienced temperatures below -10 °C, and some as low as -20 °C. The snow cover reached 30 to 40 cm in many areas, and up to 60 cm in some places. The snow caused severe problems for transport, agriculture, and industry, as well as power cuts and water shortages1.

And it is not actually that strong for +NAO, it's in the 20 to 40% range when the climate norm is probably higher than that or very near that into December, all other blocky regimes outweigh it combined.

At this time of year I don't think it matters. If there is disruption end of month it will be plenty cold enough to the east very quickly. In fact I might be correct in thinking a lot if not most classical memorable spells started innocuously as far as pressure around here is concerned.

@MATTWOLVES 3 I've just ordered these for the coming week, amazon prime Not putting a downer on it, but if and when the westerlies return we don't want to see in my opinion and preference a southerly tracking Jet. So happy to see this as if we must have SW I want the normal track and be gone with you low pressure as quickly as possible up to Iceland, you can get nice December days between fronts. Then await the mid to end month period for something better