BOTTOM LINE: Generally, normal to above-normal rainfall amounts are expected over most parts of Malawi
The period October to April is the main rainfall season over Malawi. October therefore marks the beginning of the official monitoring of rainfall season in the country. Total rainfall amounts range from 500mm to 3000mm. The main rains are experienced mainly from November starting from the south and progressively spreading to central and northern areas. However, pre-season rains locally known as Chizimalupsya are experienced at the beginning of the season which sometimes merges with main rains.
During any rainfall season, the main rain bearing systems that influence rainfall over Malawi include the Inter-Tropical Convergence Zone, Congo air mass, Easterly Waves and Tropical Cyclones. Key driving factors of the rain bearing systems over Malawi include Mean Sea Level Pressure, Upper Level Winds and Sea Surface Temperatures over the Pacific, Indian and Atlantic tropical Oceans.
Global models are currently projecting weak La Nina conditions during the 2020/2021 rainfall season. La Nina phenomenon is unusual cooling of waters over the Eastern Central Equatorial Pacific Ocean which are known to bring more rains over Southern Africa including Malawi. Past rainfall seasons that were affected by La Nina conditions similar to the 2020/2021 season are: 1983/1984, 1995/1996, 2005/2006 and 2017/2018. Climate analyses on the past La Nina years show that the country had normal onset, progression and cessation of rains.
The analyses and forecasts from climate experts in Malawi, with additional inputs from climate experts meeting and 24th Southern Africa Regional Climate Outlook Forum hosted virtually by SADC Climate Services Centre from 10th to 28th August 2020, indicate that:
The seasonal rainfall forecast for 2019-2020 for Malawi therefore is that:
• During October to December 2020, most of the southern and central areas are expected to receive normal to above-normal rainfall amounts while most of the northern areas are expected to receive normal to below-normal rainfall amounts
• During January to March 2021, most areas in the south, center and the north are expected to receive normal to above-normal rainfall amounts. However, pockets of dry conditions are expected mostly over south and centre.
The forecast implies that during the 2020/2021 rainfall season, there is high chance of many parts of the country receiving good rainfall. However, since La Nina conditions are established, extreme weather events such as floods in prone area are like to occur due to heavy rains while some parts of the country are likely to experience pockets of prolonged dry spells during the season.
It should be noted that the forecast is relevant for relatively large areas and seasonal time scales and therefore may not fully account for all factors that influence localized climate variability, such as daily, weekly and month to month variations. To account for local factors, the Department of Climate Change and Meteorological Services (DCCMS) has produced downscaled district forecasts. In addition, DCCMS will continuously issuing seasonal updates, ten-day agro-meteorological bulletins, weekly forecasts, five-day and daily forecasts. The department will continue to monitor and issue advisories on the development and movement of the tropical cyclones.
Users from the agricultural sector are encouraged to seek advice from the Ministry of Agriculture when applying this forecast in decision making such as when to plant.
Director of Climate Change and Meteorological Services
Ministry of Natural Resources, Energy and Mining
Date of issue: Monday, 7th September, 2020.