A big European circulation anomaly in 2021: totally oppositely such as in the World (!) and showing, what climate change should bring until 2100
Marek Kučera 
Anomalies of the coldest April 2021 in Europe are moreover showing, that April 2021 was even colder than in England, France or Germany in other parts of Central Europe, Balkan and parts of Eastern Europe with regional possibility of the coldest April in all-time history.
Interesting is too, that ESRL composites don´t see significant temprature anomaly in April 2021 for Ireland, while Irish Meteorological Service is saying about the coldest April in all-time history (since 1940s).
In the next composites we have looked at T2m, T850 hPa and H500 anomalies in Europe in Spring 2021 (so far), Year 2021 (so far), April 2021, May 2021 (so far) and Winter 2020/2021.
Cold character of weather across Northern Hemisphere has started in January 2021, after monstrous Major SSW, when the highest air pressure in the Earth in Mongolia (around 1094 hPa), and the lowest pressure in extratropical latitudes in Aleutian low region (around 921 hPa), were measured.
Since this event, we are suffering persisting coldwaves, thanks to peak of La nina in the winter and its delayed effects in many regions of the Earth. Anomalies are very interesting mainly in Europe.
From all composites, the most interesting are anomalies of T850 hPa above Europe computed for all Spring 2021 (so far, until 9. May) and Year 2021 (so far, until 9. May). Both maps are showing, that Spring and Year 2021 are in many parts of Europe very cold, with temperature anomalies in central parts of the continent for Spring 2021 up to -2°C and for Year 2021 for Poland, Belarus and Lithuania up to -1,5°C. Cold anomalies are reaching up to England, France and the Spain in west into Russia and all Siberia in east, southern to central Scandinavia, Scotland and northern Ural in north and Mediterranean in south.
Both anomalies are associated with deep geopotential (air pressure) anomaly above northeastern Europe and strong Greenland high (opposite anomaly), with often airflow from the Arctic into Europe in 5 months in 2021 (January, February, March, April and May so far).
According to many climatologists it should be linked with La nina behavior above Pacific and its influence into region of Greenland and northern Europe, with creating of persisting blocking circulation pattern.
Year 2021 is too colder such as average, so far, in Alaska, western and central Canada, central USA (La nina), in Canary Islands region. Siberia, India or Australia.
What is very interesting is, that H500 anomalies in 2021 or Spring 2021 are special – while in other regions of the Earth, low geopotential anomaly is outputed for northern latitudes and high for subtropical zone of high pressure, in European sector it is extremely strong Greenland´s high and anomalously weak Azorean high.
It means, that circulation in Europe is totally reverse than in other parts of the world. Probably, it should be associated with melting Arctic, global warming hole in North Atlantic and weakening of Gulf Stream group of circulation mechanisms.
This anomaly is significantly showing, how should appear many years until 2100, with expected weakening of Gulf stream and shifting of stormtrack (and cold air) in Euro-Atlantic sector into southern latitudes.
While rest of the world should enjoy climate change in their right interpretation, Europe should surprise gradually more and more cold surprises during 21. century.
Spring 2021 so far (1.3. – 9.5. 2021)
Year 2021 (1.1. – 9.5. 2021)
1.-30. April 2021 – anomalies of T2m, T850 hPa and H500
1.-9. May 2021 – anomalies of T2m, T850 hPa and H500
Winter 2020/2021 (1.12. 2020 – 28.2. 2021)
Year 2021 and Spring 2021 – World
Marek Sadowski 
Marek Kučera 
