Ontwikkeling van de QBO, zonneactiviteit, ENSO, MJO en de winter 2020/2021

Alles wat betrekking heeft op het buitenlands weer. Tropische stormen, orkanen, etc.
Sebastiaan
Berichten: 12235
Lid geworden op: 31-12-1977

Re: Ontwikkeling van de QBO, zonneactiviteit, ENSO, MJO en de winter 2020/2021

Bericht door Sebastiaan » 22-01-2021 11:28

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Karel
Berichten: 3189
Lid geworden op: 31-07-1978

Re: Ontwikkeling van de QBO, zonneactiviteit, ENSO, MJO en de winter 2020/2021

Bericht door Karel » 22-01-2021 11:39

Sebastiaan schreef:
21-01-2021 16:56
Subseasonal‐to‐seasonal (S2S) forecasts of Northern Hemisphere (NH) extratropical winter weather patterns continue to be a challenging venture. Past studies have considered the individual influence of two modes of climate variability—the Madden‐Julian oscillation (MJO) and the state of the stratospheric polar vortex (SPV)—on the NH polar jet stream and associated weather regimes. This study takes a different approach and quantifies the joint influence of the SPV and the MJO on NH S2S winter weather patterns. Using ERA‐Interim, we illustrate that variability associated with the MJO primarily influences tropospheric patterns across the North Pacific and western North America 10 to 14 days later, while SPV variability has a stronger influence on tropospheric patterns over the North Atlantic and Europe for the same lags. Over the rest of North America and into the Arctic, however, constructive and destructive interference between the MJO and the SPV teleconnections yields unique jet stream and temperature patterns that differ from the single‐mode composites. As such, S2S forecasts of temperature and jet stream patterns across much of North America may improve in accuracy by considering both modes. The study also shows that MJO Phases 2 and 3 events influence the resulting tropospheric circulation via primarily a tropospheric pathway. By contrast, MJO Phases 7 and 8 events modify both the tropospheric and stratospheric circulation with potential feedbacks on the tropospheric circulation at longer lags. Hence, the study suggests another benchmark by which to test S2S dynamical prediction systems, including the importance for modeling stratosphere‐troposphere coupling dynamics correctly. https://agupubs.onlinelibrary.wiley.com ... 19JD030771
Gehele artikel hier te vinden https://repository.library.noaa.gov/vie ... 84_DS1.pdf
Simon Lee geeft meer kans voor Scandinavian High in februari. Arctic High zal een plek gaan opzoeken begin februari. Wat is de invloed van de MJO.https://twitter.com/SimonLeeWx/status/1 ... 9790246912

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Sebastiaan
Berichten: 12235
Lid geworden op: 31-12-1977

Re: Ontwikkeling van de QBO, zonneactiviteit, ENSO, MJO en de winter 2020/2021

Bericht door Sebastiaan » 23-01-2021 16:04

Je hebt niet voldoende permissies om de bijlagen van dit bericht te bekijken.

Sebastiaan
Berichten: 12235
Lid geworden op: 31-12-1977

Re: Ontwikkeling van de QBO, zonneactiviteit, ENSO, MJO en de winter 2020/2021

Bericht door Sebastiaan » 23-01-2021 16:11

MJO volgens EC.
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Karel
Berichten: 3189
Lid geworden op: 31-07-1978

Re: Ontwikkeling van de QBO, zonneactiviteit, ENSO, MJO en de winter 2020/2021

Bericht door Karel » 24-01-2021 08:56

MJO ontwikkeling met warme stratosfeer op dit moment geeft statistisch gezien kans op eindelijk wat winter in onze omgeving. Ook de verandering in het circulatieparoon bij ECMWF oper en GFS oper is het goede signaal.

https://worldclimateservice.com/2021/01 ... c-warming/

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Sebastiaan
Berichten: 12235
Lid geworden op: 31-12-1977

Re: Ontwikkeling van de QBO, zonneactiviteit, ENSO, MJO en de winter 2020/2021

Bericht door Sebastiaan » 25-01-2021 12:31

https://rmets.onlinelibrary.wiley.com/d ... 02/qj.3974

Abstract

The simulation and prediction of winter Northern Hemisphere atmospheric blocking in the seasonal prediction systems from the European Centre for Medium‐Range Weather Forecasts (ECMWF) is analysed. Blocking statistics from the operational November‐initialised seasonal hindcasts are evaluated in three generations of models ‐ System3, System4 and System5 (SEAS5). Improvements in the climatological representation of blocking are observed in the most recent model configurations, with reduced bias over North Pacific and Greenland. Minor progress are seen over the European sector, where SEAS5 still underestimates the observed blocking frequency. SEAS5 blocking interannual variability is underestimated too and is proportional to the climatological frequency, highlighting that a negative bias in the blocking frequency implies an underestimation of the interannual variance. SEAS5 predictive skill and signal‐to‐noise ratio remain low, but interesting positive results are found over Western and Central Europe. Improved forecasts with reduced ensemble spread are obtained during El Nino years, especially at low latitudes. Complementary experiments show that the statistics of blocking are improved following atmospheric and oceanic resolution increase. Conversely, they remain largely insensitive to coupled model sea surface temperature (SST) errors. On the other hand, the implementation of stochastic parameterisations tends to displace blocking activity equatorward. Finally, by comparing seasonal hindcasts with non‐initialised climate runs using the same model it is highlighted that the largest contributor to the chronic underestimation of blocking are persistent errors in the atmospheric model. It is also shown that the SST errors have a larger impact on blocking bias in climate runs than in seasonal runs, and that increased ocean model resolution contributes to improved blocking more effectively in climate runs. Seasonal forecasts can thus be considered a suitable test‐bed for model development targeting blocking improvement in climate models


Sebastiaan
Berichten: 12235
Lid geworden op: 31-12-1977

Re: Ontwikkeling van de QBO, zonneactiviteit, ENSO, MJO en de winter 2020/2021

Bericht door Sebastiaan » 25-01-2021 21:18

EC46 EOF
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Sebastiaan
Berichten: 12235
Lid geworden op: 31-12-1977

Re: Ontwikkeling van de QBO, zonneactiviteit, ENSO, MJO en de winter 2020/2021

Bericht door Sebastiaan » 26-01-2021 10:48

The RMM index indicates the intraseasonal signal has become better organized with an increase in amplitude over the western Pacific (phases 6 and 7) during the past week. There is still some uncertainty in the forecast.......... However, dynamical models continue to favor a MJO event strengthening over the West Pacific during late Week-1 or early Week-2.
Source: https://www.cpc.ncep.noaa.gov/products/ ... update.pdf

Both GEFS and ECM Ensemble now showing a moderate strength Phase 7 progression in early February:

Source: https://www.cpc.ncep.noaa.gov/products/ ... r_wh.shtml

The CFS Outgoing Longwave Radiation forecast supports the tropical disturbance moving into the Western Pacific, particularly into the critical Kelvin-Rossby wave generation area (roughly from 120E to 120W) that will propagate the MJO impact across the NH:
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