Downburst

The ECMWF pools from 35 member countries that have their own funding and met organisations and budgets, do we add those up, including the UK, France and Germany etc, in addition to the funding ringfenced for ECMWF. I poorly expressed it perhaps. To compare the budgets doesn't consider the function of course and I have no idea of BOM other than the recent amplification. With regards to the MJO I'll stick to the ECMWF.

I'm sorry Catacol, but given the unquestionable professionalism and funding to hire the best talent and resources in capital, whatever that is the ECMWF have. I am very sceptical of any notion of inherent inaccuracies in their models for something as fundamental as MJO. Obviously I take your bias correction point in hand, and they may well apply that in given cases, but I assume they do that highly accurately. In any case I was asking sensible questions of the disparity with the MJO forecasts last week and was told, the Australians live in the region and their model will be more accurate. A strange coupling of location and mathematics I hadn't been of aware of previously. I think the bias is very much in seeing the model we want to be true myself.

He said the 26th don't worry it will be mild tomorrow.

It's quite obviously a zonal setup for now. Maybe the week between the big day and New years some transitory cold from the north, especially with height and the normal locations, but that's more than 10 days away. I am still looking at the seasonals and I am confident we will get at least one notable cold outbreak Jan to March period, more especially February or March. Better add a chart for March from the C3S (this is a professional body) (note be prepared to be attacked by the experts here, but here we go, picking March shamelessly as it's the best signal, but there is good reason given the background setup. A chart like this gives a good chance of a 2018 type event

Helping out by orientating the chart. It's a strong anomaly, but it is not northerly enough blocking really. Might be a little drier than average though if this came off. Not sure if it's winter wonderland in my view of it anyway.

I was away in the west of Ireland for the weekend on the lash and just back to 21st century and computers, and just logged in for a proper look at the models and the chat here and can’t make head nor tail of it. No retrogression of the high is what I read. We’ll have no fear, if it’s there at all it’s possible that it will pounce, just needs coaxing and a small word in the ear. It’s better to have the chance to have this, it’s happened before, it’ll happen again,

Is the Modoki El Niño somehow interfering with the normal MJO cycle and suppressing as it passes east and into or near the warmth? Just wondering if this is a factor.

Full of Northerly promise. I wonder if a low could get cut off in the med and the high then move to Scandi. Even at the end it is 1040mb and has some stopping power, even if not moving north enough. Perhaps Scandi is the ultimate destination.

Corresponding temps around that time for this run, a lot of people to finish work that day, if it happens nice and seasonal. 850 anomalies, not temps, tell a good story. Snow showers?

RE the Met Office and the signal end of month they refer to. I wonder if it is just the MJO signal (beating the hell out of that drum I know) is the duty person simply expecting -NAO chances and alluding to them, and no other data other than that seasonal take. From their own site they say How does the MJO impact UK weather? When the MJO is in its active phase over Indonesia and the West Pacific, it tends to drive a negative North Atlantic Oscillation (NAO) 2 to 3 weeks later. A positive NAO index tends to be preceded by phase 3 and 4 of the MJO, which brings milder and wetter weather across the UK. A negative NAO index tends to be preceded by phase 6 and 7, which influences a ‘blocked’ weather pattern and is often associated with colder and drier weather across the UK. The timescale of the MJO having an influence on North Atlantic weather regimes is usually 10 to 12 days. To help everyone, this is the negative NAO setup to expect. Here is the current reading, the forecast is positive, but the impact of Phase 7 to 8 won't be felt until end of month, i.e. about 10 days after 15 to 20 December, if at all of course

Right, we have set the bar, end December and January of 1963. Probably one or two bumps along the way, but I'm up in the attic later double lagging the pipes. Extract from Met Eireann reviewing that period "The first major falls were during the last week of 1962, with particularly heavy falls on the 30th and 31st of December. Casement Aerodrome measured a snow depth of 45cm on the morning of the 31st. Another heavy snowfall occured on January 15th and snow lay on the ground in many places until a spell of milder weather in early February. Drifts of up to 6 metres caused severe disruption to traffic, while the Limerick Leader reported that for the first time in living memory the frozen River Shannon could be crossed on foot near the city. Further east in Europe, the weather was particularly severe. Ice formed on many North Sea and English Channel harbours, with sea ice also reported"

I figured out why the Australian MJO forecast is higher in Phase 5 through 8 all the time. They are of course plotting these in the southern hemisphere and are upside down, so the line falls away from the COD naturally. Simple working this out in the end after trying to look into it this week.

MJO Tropics, starting in Indian Ocean and eastward movement of rain across the pacific (storms, with a lot of convection) occurs usually. This moved from the west to the east over time. It can be strong or weak and this can be measured. It can move fast or slower and again this can be measured. What we measure? The tops of the clouds at 200mb and the bottom layer at 850 pressure. This helps understand the strength of disruption. One can analyse previous pressure patterns (to pick one constant for this guide) and consider given the base state, for instance ENSO state what happened previously when the MJO was in this phase? One can then expect with certain probabilities that the atmosphere will react favourably to the way it has in the past. This is sometimes usefully shown in Composite pressure maps for the planet. Recent forecasts have shown that as December progresses we can expect a possible Phase 7 to 8 transition at some amplitude (strength) and the composite pressure maps would suggest possible high level blocking in north Atlantic/arctic. Hence the interest. At the same time a low amplitude or not getting into these phases in time will not have any effect etc. There are so many variable. As air rises a low pressure occurs and air enters underneath, a the top it cools and splits east and west. To the east it sinks and causes Higher pressure and less or no rain. The whole process moves from the East all around the tropics over a month to 6 weeks and kicks off again. Phases Section the areas off and give them a number around the tropics. If in the area one gets that number. These common Diagrams below, instead of MAP OF THE TROPICs, we can see the world split into 4 quarters, each quarter 2 phases of 8 total. It’s confusing at first, but it shows the current phase (Red), the previous phase and the forecast phase. But it also shows the amplitude of the phase, the higher above the centre circle the higher the phase, below the centre circle and it’s a very suppressed MJO signal. And of course, multiple ensemble runs to try to find consensus in the forecast. One can see even yesterday's plots show a lot of divergence in the 5 days forecast already, never mind Day 15 etc. Original post: https://community.netweather.tv/topic/99584-model-output-discussion-into-winter/?do=findComment&comment=4972108

MJO Tropics, starting in Indian Ocean and eastward movement of rain across the pacific (storms, with a lot of convection) occurs usually. This moved from the west to the east over time. It can be strong or weak and this can be measured. It can move fast or slower and again this can be measured. What we measure? The tops of the clouds at 200mb and the bottom layer at 850 pressure. This helps understand the strength of disruption. One can analyse previous pressure patterns (to pick one constant for this guide) and consider given the base state, for instance ENSO state what happened previously when the MJO was in this phase? One can then expect with certain probabilities that the atmosphere will react favourably to the way it has in the past. This is sometimes usefully shown in Composite pressure maps for the planet. Recent forecasts have shown that as December progresses we can expect a possible Phase 7 to 8 transition at some amplitude (strength) and the composite pressure maps would suggest possible high level blocking in north Atlantic/arctic. Hence the interest. At the same time a low amplitude or not getting into these phases in time will not have any effect etc. There are so many variable. As air rises a low pressure occurs and air enters underneath, a the top it cools and splits east and west. To the east it sinks and causes Higher pressure and less or no rain. The whole process moves from the East all around the tropics over a month to 6 weeks and kicks off again. Phases Section the areas off and give them a number around the tropics. If in the area one gets that number. These common Diagrams below, instead of MAP OF THE TROPICs, we can see the world split into 4 quarters, each quarter 2 phases of 8 total. It’s confusing at first, but it shows the current phase (Red), the previous phase and the forecast phase. But it also shows the amplitude of the phase, the higher above the centre circle the higher the phase, below the centre circle and it’s a very suppressed MJO signal. And of course, multiple ensemble runs to try to find consensus in the forecast. One can see even yesterday's plots show a lot of divergence in the 5 days forecast already, never mind Day 15 etc.

I used to see the mast, it was based in Ireland. Radio, someone still loves you! As Freddie sung to us. Good old Freddie. It was the week before Christmas and nowhere in Europe or North Africa was above normal temps for the first time ever

Has to squeeze in here

1049.5 is December record for Ireland. Jan 19 2020 though must have been close, I took this photo on my barometer (old inches ) that went off the scale

Will take some shifting that PV to the north west.

It's all about the core of those Atlantic heights moving more northerly. We need the momentum to come from somewhere to do that. I have no idea if it will happen or not, but Scandi High seems out so we more or less know where to place the bets. Looking forward to next set of runs and the updated 46 day charts from ECM. But still plenty of time to build something good here.

Will have to keep a beady eye on the higher pressure anomaly (isn’t necessarily actually high pressure yet) south of Greenland moving north on future runs. Period 25th to 1st. But it’s brilliant to see even this genesis hint I have to say. Looks like Scandi high is out for now.

The only thing is the temps are normal to above normal. These being the temps corresponding to the upper pressure anomalies. So that has to be considered.

Sorry, a joke on the Korean "models" (car models) having 7 year warranties, which beat the likes of European cars (re ECM) with 3 to 5 year warranties and extrapolating to the NWP

@Mike Poole @bluearmyHere is a paper, published 2022 from Copernicus, so more august body in my mind. Max-Planck Institute for the Physics of Complex Systems, Reading etc From the Abstract: "Although in the last decades state-of-the-art climate models have proved their capability for forecasting the MJO exceeding the 5 weeks prediction skill, there is still room for improving the prediction. In 5 this study we use Multiple Linear Regression (MLR) and a Machine Learning (ML) algorithm as post-processing methods to improve the forecast of the model that currently holds the best MJO forecasting performance, the European Centre for Medium-Range Weather Forecast (ECMWF) model." https://egusphere.copernicus.org/preprints/2022/egusphere-2022-2/egusphere-2022-2.pdf I have given it a once over, but will have a more focused read later.

The South Korean weather model has a 7 day warranty apparently, has ECM worried with their 5 day warranty.

As we all know the MJO is ticking away all the time since the ice age ended and there is a danger it will be taken too seriously for cause and affect when needed for a cause. I think the main issue I have is this BOM chart, seems always to be in insane amplification, like 100% more. So I'll be sticking with ECMWF and I certainly don't buy the argument that Australians have the MJO nailed in their computer models and the rest don't, hard to believe that given the age we are in and funding ECMWF and GFS get etc. Dec 5th ECMWF Dec 4 BOM