TOKYO - Japan is expected to experience a warmer-than-normal winter as the El Nino phenomenon currently affecting the Pacific Ocean has reached its strongest level on record, with the Japan Meteorological Agency announcing on October 10th that unusually high sea surface temperatures are likely to persist through the coming winter months.
The agency reported that sea surface temperatures in September in the El Nino monitoring region off the coast of Peru in South America were 4 degrees Celsius above the reference level, the largest positive deviation recorded since observations began. The exceptionally high temperatures indicate that the current El Nino has surpassed previous episodes in intensity.
El Nino, which involves an abnormal warming of surface waters in the central and eastern equatorial Pacific, is regarded as one of the factors contributing to unusual weather patterns worldwide. The phenomenon influences atmospheric circulation, affecting temperatures, precipitation and storm development across different regions.
Masayuki Kyoda, director of the JMA's Atmosphere and Ocean Department, said historical observations indicate that Japan tends to experience warmer winters during El Nino events. "Looking at past El Nino events, winters in Japan have tended to be warmer than normal," he said.
According to the agency's latest outlook, the current conditions are expected to continue through winter, with the probability of El Nino persisting estimated at 100% for the forecast period. Sea surface temperature anomalies have remained particularly pronounced since the summer, with August and September showing exceptionally high readings.
The agency forecasts that temperatures in northern Japan will be near or above seasonal averages, while eastern and western Japan, Okinawa and the Amami Islands are expected to experience above-normal temperatures.
The outlook for October through December also suggests that relatively warm atmospheric conditions will persist across much of the country. Changes in the position of the prevailing westerly winds are expected to influence weather patterns, although the shift is not forecast to be strong enough to bring unusually intense outbreaks of cold air.
Precipitation during the three-month period is expected to be near or slightly above normal, partly because disturbances along the prevailing westerly wind belt could produce periods of unsettled weather. This may result in frequent changes between several days of clear skies and spells of rain.
Despite the general warming trend, the agency cautioned that the arrival of colder air from late November into December could still bring periods of substantial snowfall, particularly along the Sea of Japan coast. A warmer seasonal outlook therefore does not necessarily mean that individual cold spells or heavy snow events will be absent.
The unusually powerful El Nino may already have influenced Japan's weather during the summer. Changes in atmospheric circulation associated with the phenomenon are considered a possible contributing factor to the large number of typhoons that developed in August.
A total of 10 typhoons formed during August, an unusually high number for a single month. The agency suggested that the strength of El Nino may have indirectly altered atmospheric conditions in ways that favored tropical cyclone development around Japan and the western Pacific.
El Nino's influence on tropical cyclone activity is complex, with changes in atmospheric circulation potentially affecting where storms form and how they develop. The exceptionally strong conditions observed this year could therefore continue to influence weather patterns beyond the immediate winter temperature outlook.
With the phenomenon expected to remain strong over the coming months, Japan faces the prospect of persistently above-average temperatures, fluctuating precipitation patterns and continued weather variability, even as occasional cold outbreaks bring more typical winter conditions to parts of the country.
Source: FNN
