subseasonal

Subseasonal refers to a timescale in weather and climate forecasting that falls between short-range forecasts (typically up to 10 days) and seasonal forecasts (usually months to a year). This intermediate period, often spanning from about two weeks to two months, is a crucial area of research and operational forecasting.

Predicting weather patterns on subseasonal timescales is challenging because the signals are weaker and more complex than those on shorter or longer timescales. While day-to-day weather is largely driven by chaotic atmospheric dynamics, and seasonal climate is influenced by slower, larger-scale drivers like ocean temperatures, subseasonal variability is thought to be a mix of both. Factors such as the Madden-Julian Oscillation (MJO), a notable pattern of cloud and rainfall that propagates eastward around the globe, play a significant role in subseasonal weather. Other influences include atmospheric waves and interactions between the atmosphere and the land or ocean surface.

Advances in subseasonal forecasting are vital for sectors such as agriculture, water resource management, energy production, and disaster preparedness. Improved subseasonal forecasts can help farmers make decisions about planting and harvesting, assist in managing water supplies during droughts or floods, and guide energy companies in anticipating demand. The development and refinement of subseasonal prediction models and the understanding of the underlying physical processes are active areas of scientific investigation.