Extreme Weather Event (EWE)
A subset of "Hazard" and "Threat" to CI comprise Extreme Weather Events (EWE) which causes a CI disruption or, even more often, a Common Cause Failure of multiple CI.
EWE comprise:
- long duration drought
- extreme precipitation in a short period of time (e.g., flash floods, water bombs)
- (extreme) cold wave / cold snaps / ice & snow storms
- (extreme) heat wave
- extreme wind (hurricanes, tornadoes, Derecho, etc.)
Contents
Definitions
EU definitions
CLIMATE-ADAPT
Definitions of rare vary, but an extreme weather event would normally be as rare as or rarer than the 10th or 90th percentile of the observed probability density function. By definition, the characteristics of what is called extreme weather may vary from place to place in an absolute sense. Single extreme events cannot be simply and directly attributed to anthropogenic climate change, as there is always a finite chance the event in question might have occurred naturally. When a pattern of extreme weather persists for some time, such as a season, it may be classed as an extreme climate event, especially if it yields an average or total that is itself extreme (e.g. drought or heavy rainfall over a season).
International Definitions
IPCC
Definitions of rare vary, but an extreme weather event would normally be as rare as or rarer than the 10th or 90th percentile
of a probability density function estimated from observations.
National Definitions
Australia
Definitions of rare vary, but an extreme weather event would normally be as rare as or rarer than the 10th or 90th percentile of a probability density function estimated from observations.
Moreover, Australia has defined severe weather:
Severe weather is often associated with extreme convective weather (tropical cyclones, tornadoes, severe
thunderstorms, squalls, etc.) and with storms of freezing precipitation or blizzard conditions.
Germany
If extreme weather persists for a long period of time, it may be classified as an “extreme climate event”.
Netherlands
United Kingdom (UK)
United States
NOAA
The U.S. National Oceanic and Atmospheric Administration (NOAA) uses a definition of extreme weather based on an event's climatologically-expected distribution. An event is called extreme if occurs, for example, only five per cent or less of the time. NOAA notes, however, that the exact choice of cut-off of the climatologically probability value used in the definition is somewhat arbitrary. A simple example of extreme weather is therefore when the temperature drops to a level which occurs less than five per cent of the time, say below -20 C. Extreme events, by definition, are rare.
Standard Definition
Discussion
See also
Notes
- ↑ European Climate Adaptation Platform (CLIMATE-ADAPT) Glossary
- ↑ Mach, K.J., S. Planton and C. von Stechow (eds.). Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Annex II: Glossary. [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, pp. 117-130.
- ↑ Australian climate change glossary
- ↑ Australian Emergency Management Glossary, Emergency Management Australia (1998)
- ↑ Combating Climate Change: The German Adaptation Strategy
- ↑ weer website extreme weer Nederland
- ↑ The National Adaptation Programme: Making the country resilient to a changing climate, UK Government (2013)
