'Seasonal Highlights' has been issued in PDF format since spring 2007 as a seasonal bulletin focusing on the seasonal highlights of the monitoring results. For monthly information, please refer to 'Monthly Highlights on the Climate System.'
Highlights in Winter (December 2024 - February 2025)
- In the equatorial Pacific, remarkably positive SST anomalies were observed in the western part and negative anomalies were observed in the central part, indicating La Niña-like conditions.
- Convective activity was enhanced from the eastern Indian Ocean to Southeast Asia and in and around southern Central America, and suppressed from Africa to the central Indian Ocean and from the western to central equatorial Pacific.
- In association with enhanced convection, anti-cyclonic circulation anomalies straddling the equator were seen over the eastern Indian Ocean. Cyclonic circulation anomalies were seen over Japan.
- The polar front jet stream meandered southward over Japan. The westerly jet stream over the North Pacific was stronger than normal.
- In the sea level pressure field, the Aleutian Low and the Siberian High were both stronger than normal, indicating enhanced East Asian winter monsoon.
- Seasonal mean temperatures were significantly below normal in Okinawa/Amami and below normal in western Japan, while those were above normal in Northern Japan.
- Seasonal precipitation amounts were the smallest on the Pacific side of eastern/western Japan on record for winter since 1946/47, and tied for the smallest on the Sea of Japan side of western Japan. While those were significantly above normal on the Sea of Japan side of eastern Japan, and above normal on the Sea of Japan side of northern Japan. Seasonal snowfall amounts were above normal on the Sea of Japan side of western Japan.
The descriptions from Spring-2011 to Winter-2021 issue are based on the former climatological normal (1981-2010) unless otherwise stated.
In the descriptions until Winter-2011 issue, 1979-2004 average is used as climatological normal unless otherwise stated.
The descriptions until Autumn-2013 issue are based on the JRA-25/JCDAS datasets.
The descriptions from Winter-2014 to Winter-2023 issue are based on the JRA-55 reanalysis.
Figures and Tables
Notice: Products based on JRA-3Q were updated to those with improved quality in terms of tropical cyclone analysis. OLR-related products from January 1991 are based on NOAA CPC Blended OLR (CBO).
Notice: Figures of 'Atmospheric Circulation', 'Time Cross Section', and 'Indices' have been revised with improved quality data regarding tropical cyclone analysis. (18 June 2024)
Notice: Depending on the availability of NOAA CPC Blended OLR (CBO) data, updates may be delayed or figures may be filled with gray indicating data missing.
