A consensus forecast issued by a group of South Asian countries was just released and projects near-normal monsoon rainfall for summer 2018. The South ASian Climate Outlook Forum (SASCOF) was established in 2010 and met last week, together with experts from both the World Meteorological Organization and user communities in India. They considered dynamical and statistical forecasts issued by all of the world’s major weather prediction centers, and issued this consensus statement:
“Normal rainfall is most likely during the 2018 southwest monsoon season (June – September) over most parts of South Asia. However, above normal rainfall is likely over some areas of east central India and southeastern parts of the region. Below-normal rainfall is likely over some areas of southern, northwestern and northeastern parts of South Asia.”
Visually, here is what this looks like (excerpted from their full forecast discussion):
The APEC climate center in Korea also issued new seasonal forecasts yesterday, which are generally have South Asia being a little wetter than the above consensus forecast, especially during early summer:
Globally, these are similar to the forecasts that APEC released one month ago; if we limit our focus to land regions, a major feature is that North America and southwestern Asia are dry in early summer (through July, while much of the Sahel is wet in late summer. The dryness in southwestern Asia is a big deal because Afghanistan is already in a prolongued drought, with millions of people being food insecure, according to the United Nations. Afghanistan isn’t typically thought of as a monsoon region because it receives most of its rain in winter and is dry in summer, but much of that summer dryness occurs because of the downward atmospheric motion induced over Afghanistan by the South Asian monsoon (e.g. this paper by Bollasina and Nigam).