Severe weather warnings

Some definitions

Natural Hazard: Weather or flood-related situation withpotential to inflict loss or damage to the community or environment. While hazard may induce a crisis, they do not necessarilylead to disasters.

Natural Disaster: A catastrophic event caused by a natural hazard that severely disrupts the fabric of a community and usually requires intervention of government to return the community to “normality”.

Some definitions

In some instances, natural disasters can not be prevented from occurring, however their overall impact can be significantly reduced through Disaster Mitigation.

Disaster mitigation: Process of managing the “risks” associated with potential natural disasters so that loss may be minimized and even eliminated.- Appropriate Response actions

Disaster risk: The likelihood of harmful consequences arising from the interaction of natural hazards and the community.

Some definitions

Risk = Hazard Probability x Vulnerability

Nature of Hazard: Understand hazards of the past, monitoring of present, and predicting the future.

Vulnerability: The extent of a communities susceptibility or resilience to loss or damage from a natural hazard.

Reducing disaster vulnerability requires increasing knowledge about the likelihood, consequences, imminence and presence of natural hazards, and empowering individuals, communities and public authorities with that knowledge to lower the risk before severe weather events, and respond immediately during and afterwards.

Early warning

Empower individuals and communities to respond appropriately to a threat in order to reduce the risk of death, injury, property loss and damage.

Provide early warning of weather, water and climate hazards, for operational decisions

Support risk and impact assessments to determine who is at risk and why

To improve forecasts and analyses to help reduce or remove risks

Temperature: Very Cold conditions

Maximum Temperature below 10 degrees Celsius

Minimum Temperature below -10 degrees Celsius

Temperature: Very Cold conditions

Maximum Temperature below 10 degrees Celsius

Minimum Temperature below -10 degrees Celsius

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Very Cold conditions: Meteorology

EUMETSATMSG: Air-mass image 26 August 2008 07h00Z

Cold air moving from the far south

Temperature: Very Cold conditions

Maximum Temperature below 10 degrees Celsius

Minimum Temperature below -10 degrees Celsius

Very Cold conditions: High Risk areas

EUMETSATMSG: Air-mass image 26 August 2008 07h00Z

• Mountains• High lying areas

Sutherland

Snow

Temperature: Very Cold conditions

Maximum Temperature below 10 degrees Celsius

Minimum Temperature below -10 degrees Celsius

Wind Chill conditions

EUMETSATMSG: Air-mass image 26 August 2008 07h00Z

• The colder effect that are felt on the skin as a result of cooling effect of the wind.• Felt on the skin and eventually the whole body.

Temperature: Wind chill

Sensible temperature less than or equal to -15 degrees Celsius

Effects are worse under wet conditions

Very Cold conditions: At Risk People

Mountaineers, climbers and hikers

Homeless peoplePeople in informal settlements

Added risk of FIRES

Senior citizens

Pets

The sickIncrease

electricity usage

Temperature: Very High

Maximum Temperature 40 degrees Celsius and above

Temperature: Very uncomfortable

Discomfort Index of 38 degrees Celsius and above

High temperatures and High humidity

Temperature: Effects

Maximum Temperature 40 degrees Celsius and above

Sunburn Danger

Hikers

Sports

Diminishing Water

Resources

Traffic jams

Temperature: Heat-wave

Three consecutive days when the Maximum temperatureis expected to be at least 5 degrees higher than the averageHigh Maximums of the hottest month.

Temperature and Wind: Veld Fires

Weather conditions that could lead to runaway fires.

Depends on Temperature, wind conditions, humidity, condition of fuel etc.

Climate change:Longer fire season for west coast and adjacent interior, central Western Cape

Wind: Gale force winds or higher

Winds speeds greater than 35kt or 65km/h

Risk of falling, fallen and blowing debris

Major effect on fishing Industry particularly off west coast

Wind: Widespread sandstorms

Scouring effectVery low visibilityDangerous road conditionsDangerous flying conditions

Normally in windy, low vegetative areas: West coast north of Lamberts Bay

May become more prevalent in climate change scenarios

Temperature: Black frost

The freezing of plant sap that results in black appearanceOf the plants.

Farmers and Gardeners

Wind: Tornadoes

Harrismith

Manenberg, 1999

Springbok!! In 2008

Severe Thunderstorms

Lightning: Electricity spikes and power outages

Traffic jams:

Obvious danger to Aviation

Hail stones more than 19mm

Property damage

Crop damage

Heavy rain

80% probability of precipitation greater than 50mmover 24 hours

Very low visibility and slippery roadsDangerous road conditionsMay flood low lying areas

Flooding

Damage to property

Erosion

Inaccessible roads

Damaged infrastructure

Debris

Raging rivers

Maritime: Waves higher than 5m, 7m

Abnormal wave height

High wavesOffshore drillingFishing Industry

Maritime: Tropical cyclones

LightningStorm Surge

Heavy rain and flooding

Huge waves

Aviation: Large Hail

Aviation: Severe Turbulence and Mountain waves

Aviation: icing and Ice accretion

Aviation: Volcanic Ash

Regional Specialist Meteorological CentreHeavy rainfall

Strong Winds

Early warning

Strive to ensure that every person or organization at risk• Receives the information • Understands the information• BELIEVES the information• Personalizes the risk• Make correct decisions• Respond in a timely manner

Early warning

Effective early warning should be:• Short, concise, understandable and actionable

• What, where, when, why, how to respond

Should be presented in several different formats – text-graphics-color coded categories-audio; should included specific actions for people to take to respond to the event.

http://upload.wikimedia.org/wikipedia/commons/a/a2/Mountaineers_in_High_Tatry_mountains_winter.jpg

www.capetown.dj/people/people.html

http://www.jokesy.com/images/old-lady-senior-citizens-jokes1.jpg

http://happytrailsboardingkennel.com/sitebuilder/images/sick_puppy-600x319.jpg

http://weathersavvy.com/windysnow_OPT.jpg

http://ed101.bu.edu/StudentDoc/Archives/ED101fa06/mattwall/Weather%20Pictures/thunderstorm.jpg

http://www.airliners.net/aviation-forums/general_aviation/read.main/2271578

http://www.iopara.ca/research.html

Early warning