Monthly Highlights on the Climate System

'Monthly Highlights on the Climate System' has been issued in PDF format since March 2007 as a monthly bulletin focusing on the monthly highlights of the monitoring results.

Notice: From 19 May 2021 onward, the products in this page are based on the new climatological normal (1991-2020 average) unless otherwise stated.

Highlights in August 2021

- Though ENSO-neutral conditions persisted (see El Niño Outlook updated on 10 September 2021) negative SST anomalies were observed from the central to eastern part of the equatorial pacific except east of 110°W. In the Indian Ocean, remarkably positive SST anomalies were observed south of Sumatra.
- Active stationary fronts formed between the Okhotsk High and the North Pacific Subtropical High and moist air along them brought record-breaking monthly precipitation amounts to western Japan.
- Monthly precipitation amounts were extremely high from eastern Japan to central China and from central to western Indonesia, and extremely low in southeastern Canada.
- Convective activity was enhanced from southwest of Sumatra to the Maritime Continent, and suppressed from the Bay of Bengal to the Philippines.
- Corresponding to above-mentioned convective activity anomalies, the subtropical jet stream shifted southward from its normal position from Eurasia to Japan, and meandered southward over the area west of Japan.

Full version (PDF)

Monthly Highlights on the Climate System (August 2021)
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The descriptions from May-2011 to April-2021 issue are based on the former climatological normal (1981-2010 average).
In the descriptions until April-2011 issue, 1979-2004 average is used as climatological normal unless otherwise stated.
The descriptions until January-2014 issue are based on the JRA-25/JCDAS datasets.

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Tokyo Climate Center, Climate Prediction Division.
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