- We have seen the year 2020 was, weatherwise, a remarkable and deadly year by various extreme weather events.
- Including the record-breaking Atlantic hurricane season, wildfires in Siberia, and winter storms in both Europe and the United States.
- And the year ended with a bang, setting a new North Pacific low-pressure record of 921 mbar as a powerful extratropical storm hit Alaska on the last day of 2020.
- While just a day earlier, a new world record for high-pressure has been set in Mongolia, 1094 mbar!
A recent news article published in the Severe Weather Europe deals with the new world record for high-pressure that has been set in Mongolia, 1094 mbar.
A new world record for extreme air pressure
The extreme cold over parts of Asia mentioned earlier above, has also set another extreme record for air pressure – a world record for the highest sea-level pressure!
The Mongolian weather station Tsetsen-Uul’s mean sea-level pressure rose to an unprecedented 1094.3 mbar (or 32.31 inches).
This broke the previous record of 1089.4 mbar set on Dec 30th, 2004 at the same station.
Automatic weather station
Actually, a new world record for the highest mean sea-level pressure has likely been set in a high mountain valley (plateau) in Mongolia, central Asia.
An automatic weather station located in Tsetsen-Uul, western Zavkhan province, Mongolia has recorded a mean sea-level pressure of 1094.3 mbar along with bitter temperatures of -45.5 °C (-50 °F).
When does the highest values of sea-level pressure occur?
The highest values of the mean sea-level pressure normally occur in frigid winter months with snow on the ground, as dense air sinks towards the surface, e.g. in the valleys.
When the night skies are clear and strong temperature inversion forms, almost no wind is present which helps the cooling air to sink towards the bottom of the valley and become even colderm as it doesn’t mix with the lack of winds.
And the temperatures are much lower in the bottom of the valley than it is along the surrounding slopes.
The surface pressure analysis
The surface pressure analysis below reveals this extratropical storm evolution from its birth near Japan on Tuesday, Dec 29th, entering the explosive intensification while gradually growing its size and rapidly lowering its central pressure through Wednesday.
Then, it deepens considerably on Thursday when the peak, lowest central pressure, has been reached in the morning hours (local Pacific/Alaska time):
- 923 mbar at 00 UTC, Jan 1st
- 921 mbar at 18 UTC, Dec 31st
- 921 mbar at 12 UTC, Dec 31st
- 928 mbar at 06 UTC, Dec 31st
- 941 mbar at 00 UTC, Dec 31st
- 960 mbar at 18 UTC, Dec 30th
- 972 mbar at 12 UTC, Dec 30th
- 986 mbar at 06 UTC, Dec 30th
- 996 mbar at 00 UTC, Dec 30th
- 1001 mbar at 18 UTC, Dec 29th
- 1008 mbar at 12 UTC, Dec 29th
Violent winds associated with this Monday’s low and the new large storm on Tuesday will generate significant waves of 8-12 meters towards the coast of Southeast Alaska and the Pacific Northwest of western Canada and the United States.
Extratropical storms are expected in the coming week
The overall very active pattern across the North Pacific continues, so new extratropical storms are expected in the coming week.
The largest storm is likely to arrive on Tuesday and would potentially be quite intense.
The ECMWF model guidance suggests that its central pressure would push even below 950 mbar while the storm will be moving with its center just south of the Aleutian Islands towards the Gulf of Alaska.
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Source: Severe Weather Europe
