knocker

https://confluence.ecmwf.int/display/FUG/Section+8.2.6+Madden-Julian+Oscillation+Output

The links between the Madden-Julian Oscillation and European weather regimes Abstract Skillful weather forecasting on sub-seasonal timescales is important to enable users to make cost-effective decisions. Forecast skill can be expected to be mediated by the prediction of atmospheric flow patterns, often known as weather regimes, over the relevant region. Here, we show how the Grosswetterlagen (GWL), a set of 29 European weather regimes, can be modulated by the extra-tropical teleconnection from the Madden-Julian Oscillation (MJO). Together, these GWL regimes represent the large-scale flow characteristics observed in the four North Atlantic-European classical weather regimes (NAE-CWRs), while individually capturing synoptic scale flow details. By matching each GWL regime to the nearest NAE-CWR, we reveal GWL regimes which occur during the transition stages between the NAE-CWRs and show the importance of capturing the added synoptic detail of GWL regimes when determining their teleconnection pattern from the MJO. The occurrence probabilities of certain GWL regimes are significantly changed 10–15 days after certain MJO phases, exhibiting teleconnection patterns similar to their NAE-CWR matches but often with larger occurrence anomalies, over fewer consecutive MJO phases. These changes in occurrence probabilities are likely related to MJO-induced changes in the persistence and transition probabilities. Other GWL regimes are not significantly influenced by the MJO. These findings demonstrate how the MJO can modify the preferred evolution of the NAE atmospheric flow, which is important for sub-seasonal weather forecasting. https://link.springer.com/article/10.1007/s00704-020-03223-2

Lubbly jubbly to end the week

Just had a quick scamper through the Mod. thread and I know not why but “Other than that Mrs. Lincoln, how was the play?” flashed into my mind.

I can't remember the last time I've seen so much frenzied .......

It is because the low deconstructs as the jet hits the buffers of the block to the east and rapidly veers

Shortwaveitus - an endemic disease that tends to proliferate in winter months. There is no known cure but can be treated with copious amounts of Diazepam and plenty of bed rest.

Sacre bleu.......we are on course for possible the shortest winter on record

Put simply the ecm next week has intense trough development in the Atlantic driven by a strong jet which at the same time amplifies the Euro ridge which effectively mixes out the colder air in the west, including the UK and isolates the colder air to the east. Original post: https://community.netweather.tv/topic/99584-model-output-discussion-into-winter/?do=findComment&comment=4965504

Put simply the ecm next week has intense trough development in the Atlantic driven by a strong jet which at the same time amplifies the Euro ridge which effectively mixes out the colder air in the west, including the UK, and isolates the colder air to the east.

The dash to make a silk purse out of a pigs ear is now well underway

And nobody was listening

Yes when something looks odd the first question should be why?

Surface chart

I take it you do appreciate that currently the analysis has a warm front edging slowly north on Sunday into the cold air so the ens not too surprising

Well now the moderate rain here has turned to moderate snow for a while this morning. A good example of evaporative cooling

Game over.....just as well close the mod. thread for the rest of the winter

A short summary of the MJO MJO_summary.pdf

Time to wheel out "Will it Snow" by John once again https://community.netweather.tv/learning/basics/will-it-snow-by-john-holmes-r96/

Oh God............just when I thought things couldn't get any worse in here

There is a strong rumour doing the rounds that this thread is going to be renamed the gymkhana thread.

I didn't say alone and bluearmy has pre-empted my reply which i have made in more detail elsewhere

Not necessarily

Not even with a strat/trop coupling?

Because given the rather complex nature of the evolution minor changes with the energy flows can make a big difference as highlighted by the development and track of the frontal wave next Friday. Cryptic assertions like the one I responded to are absolutely no help to people trying to understand what is going on