In this Climate watch, the ocean-atmosphere phenomenon that often cause greatest disruption of the normal climatic conditions within the GHA such as the El Niño-Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) are reviewed together with the potential impact and outlook for the October to December rainfall season. The bulletin also considers the ENSO updates from the global climate centres including the World Meteorological Organization (WMO) for October 2016. Click here to download the complete climate watch
This current climate watch gives an update of the 2015-16 El-Niño phenomenon, as well as the regional climate impacts during the period extending from June 2015 to February 2016. Also included in the discussion are the modification of ENSO regional impacts by the complex interactions with other global and regional systems such as Indian Ocean Dipole (IOD), Atlantic Oscillatory systems, topographical systems; the large inland water bodies, among others. The major regional climate anomalies that were observed over GHA during the seasons of JJAS, OND and DJF of 2015 are also included in this climate watch. Click here to download the complete climate watch
This current climate watch gives an update of the evolving El-Niño phenomenon, as well as the potential regional climate impacts during the period extending from September 2015 to February 2016. Also included in the discussion are the potential modification of ENSO regional impacts by the complex interactions with other global and regional systems such as Indian Ocean Dipole (IOD), Atlantic Oscillatory systems, topographical systems; the large inland water bodies, among others. The major regional climate anomalies that were observed over GHA during the months of May to July2015 are also included in the climate watch.
Download the full climate watch here.
El Niño advisory by NOAA indicate that there is an approximately 90% chance that the El Niño will continue through Northern Hemisphere summer 2015, and a greater than 80% chance it will last through 2015 (http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_ advisory/ensodisc). El Niño is characterized by unusually warm ocean surface temperatures in the central and eastern tropical Pacific. The opposite phenomena often referred to as La Niña is associated with cooling-off the ocean surface temperatures in the central and eastern tropical Pacific. El Niño and La Niña have significant impacts on general circulation and climate in many parts of the world.The regional impacts of El-Niño phenomenon are often modulated by regional scale processes. For the GHA climate impact during June to August season, of importance is the phase of the Indian Ocean Dipole (IOD) as well as likely influence of the Eastern Atlantic. This climate watch provides a summary of regional climate stresses that was observed over GHA during the months of March – May 2015 as well as a brief on the ongoing El Niño event. The potential impacts of El-Niño over GHA during June-December 2015 period is also highlighted. A brief review of El-Niño is first provided in the following section. Download the Climate Watch here.
ICPAC’s mission is to foster climate information, prediction, timely early warning and applications for disaster risk reduction and sustainable development in the Greater Horn of Africa (GHA). ICPAC also supports all relevant IGAD’s disaster risk reduction programmes and activities including those related to the IGAD Drought Disaster Resilience and Sustainability Initiative (IDDRSI) Strategy. The overall objective of the IGAD IDDRSI strategic plan is led by the vision “A peaceful and prosperous IGAD region free from drought disasters and emergencies”. IDDRSI was one of the key outcomes of the summit of the Heads of State and Government of the East African Community (EAC) and the Inter-Governmental Authority on Development (IGAD) that was held in Nairobi, Kenya on 9th September 2011. The summit that was triggered by the impacts of the severe regional scale drought of 2009-2011 called for effective early actions from climate early warning systems.
ICPAC produces regular regional 10 day, monthly and seasonal climate early warning updates. ICPAC also releases a special early warning bulletin known as climate watch to provide among others any new or evolving global /regional climate systems that may have some impacts on regional climate extremes such as floods and droughts with far reaching socio-economic implications.
WMO El Niño update (http://www.wmo.int/pages/prog/wcp/wcasp/documents/WMO_ENSO _Dec14_Eng.pdf) released on 4 December in partnership with the major climate centers worldwide indicate that the steady warming of the tropical Pacific Ocean over previous two months resulted in ocean surface temperatures reaching weak El Niño levels. Mix responses are however being observed over the overlying atmosphere, with some indicators exceeding El Nino thresholds, while others such as cloudiness and precipitation remain neutral. Models and expert opinion suggest there is approximately a 70% chance that a weak El Niño event will become established by February 2015.
December – February is usually a dry season over most parts of GHA with exception of parts of southern Tanzania. Episodic wet conditions are however common during some of the El-Niños. The regional impacts of El-Niños are often influenced by many regional climate systems including Indian Ocean Dipole (IOD). This climate watch provides a summary of regional climate stresses that was observed over GHA during the months of September to November 2014 as well as the projected outlooks for the period covering December 2014 and February 2015.
A part from examining the potential impacts of the evolutions of El-Niño over eastern equatorial Pacific Ocean, the current and projected regional climate systems including IOD are also addressed. Details of the expected climate for specific countries may be obtained from individual NMHSs.
A lot of publicity has been given to the potential impacts of the evolving El-Niño over eastern equatorial Pacific Ocean, based on the past severe impacts floods that some of them have been associated with in the past. A brief review of El-Niño is provided in the following sub-section.
Download the Dec-2014 to Feb-2015 Climate Watch (En) (Fr)