Causes of the Record-Breaking Pacific Northwest Heatwave, Late June 2021
The extreme heat event that hit the Pacific Northwest (Oregon, Washington, southern British Columbia) at the end of June 2021 was 3 °C greater than the previous Seattle record of 39 °C; larger extremes of 49 °C were observed further inland that were 6 °C above previous record. There were hundreds of...
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ftmdpi:oai:mdpi.com:/2073-4433/12/11/1434/ 2023-08-20T04:04:41+02:00 Causes of the Record-Breaking Pacific Northwest Heatwave, Late June 2021 James E. Overland agris 2021-10-30 application/pdf https://doi.org/10.3390/atmos12111434 EN eng Multidisciplinary Digital Publishing Institute Climatology https://dx.doi.org/10.3390/atmos12111434 https://creativecommons.org/licenses/by/4.0/ Atmosphere; Volume 12; Issue 11; Pages: 1434 heatwave polar vortex extreme events pacific northwest Text 2021 ftmdpi https://doi.org/10.3390/atmos12111434 2023-08-01T03:06:51Z The extreme heat event that hit the Pacific Northwest (Oregon, Washington, southern British Columbia) at the end of June 2021 was 3 °C greater than the previous Seattle record of 39 °C; larger extremes of 49 °C were observed further inland that were 6 °C above previous record. There were hundreds of deaths over the region and loss of marine life and forests. At the large scale prior to the event, the polar vortex was split over the Arctic. A polar vortex instability center formed over the Bering Sea and then extended southward along the west coast of North America. The associated tropospheric trough (low geopotential heights) established a multi-day synoptic scale Omega Block (west-east oriented low/high/low geopotential heights) centered over the Pacific Northwest. Warming was sustained in the region due to subsidence/adiabatic heating and solar radiation, which were the main reasons for such large temperature extremes. The seasonal transition at the end of spring suggests the possibility of a southern excursion of a polar vortex/jet stream pair. Both the Pacific Northwest event in 2021 and the Siberian heatwave climax in June 2020 may be examples of crossing a critical state in large-scale atmospheric circulation variability. Text Arctic Bering Sea MDPI Open Access Publishing Arctic Bering Sea Pacific Atmosphere 12 11 1434 |
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Open Polar |
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MDPI Open Access Publishing |
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ftmdpi |
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English |
topic |
heatwave polar vortex extreme events pacific northwest |
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heatwave polar vortex extreme events pacific northwest James E. Overland Causes of the Record-Breaking Pacific Northwest Heatwave, Late June 2021 |
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heatwave polar vortex extreme events pacific northwest |
description |
The extreme heat event that hit the Pacific Northwest (Oregon, Washington, southern British Columbia) at the end of June 2021 was 3 °C greater than the previous Seattle record of 39 °C; larger extremes of 49 °C were observed further inland that were 6 °C above previous record. There were hundreds of deaths over the region and loss of marine life and forests. At the large scale prior to the event, the polar vortex was split over the Arctic. A polar vortex instability center formed over the Bering Sea and then extended southward along the west coast of North America. The associated tropospheric trough (low geopotential heights) established a multi-day synoptic scale Omega Block (west-east oriented low/high/low geopotential heights) centered over the Pacific Northwest. Warming was sustained in the region due to subsidence/adiabatic heating and solar radiation, which were the main reasons for such large temperature extremes. The seasonal transition at the end of spring suggests the possibility of a southern excursion of a polar vortex/jet stream pair. Both the Pacific Northwest event in 2021 and the Siberian heatwave climax in June 2020 may be examples of crossing a critical state in large-scale atmospheric circulation variability. |
format |
Text |
author |
James E. Overland |
author_facet |
James E. Overland |
author_sort |
James E. Overland |
title |
Causes of the Record-Breaking Pacific Northwest Heatwave, Late June 2021 |
title_short |
Causes of the Record-Breaking Pacific Northwest Heatwave, Late June 2021 |
title_full |
Causes of the Record-Breaking Pacific Northwest Heatwave, Late June 2021 |
title_fullStr |
Causes of the Record-Breaking Pacific Northwest Heatwave, Late June 2021 |
title_full_unstemmed |
Causes of the Record-Breaking Pacific Northwest Heatwave, Late June 2021 |
title_sort |
causes of the record-breaking pacific northwest heatwave, late june 2021 |
publisher |
Multidisciplinary Digital Publishing Institute |
publishDate |
2021 |
url |
https://doi.org/10.3390/atmos12111434 |
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agris |
geographic |
Arctic Bering Sea Pacific |
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Arctic Bering Sea Pacific |
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Arctic Bering Sea |
genre_facet |
Arctic Bering Sea |
op_source |
Atmosphere; Volume 12; Issue 11; Pages: 1434 |
op_relation |
Climatology https://dx.doi.org/10.3390/atmos12111434 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.3390/atmos12111434 |
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Atmosphere |
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12 |
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11 |
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1434 |
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