Southwest Monsoon is progressing at a good pace over the country. Monsoon, which hit Kerala with a delay has reached many States. With the arrival of monsoon in Telangana late June, it is raining continuously for over a week now.
In such a situation, Indian Meteorological Department (IMD) has issued an orange alert for Greater Hyderabad Municipal Corporation (GHMC) for Friday and Saturday and red alert for a couple of northern districts of Telangana and orange for other districts. IMD also issues yellow, orange, red, green alert regarding the possibility of heavy rain. Read here what do these colour codes mean…
Colour codes are used in weather warnings for bringing out the severity of the weather phenomena expected” as per the Indian Meteorological Department (IMD). Colour codes are used in weather warnings for bringing out the severity of the weather phenomena expected as per the Indian Meteorological Department (IMD). The main purpose is to forewarn disaster management authority and people to keep themselves ready for necessary action related to disaster risk reduction.
Colour- Coded Weather Warning
It is issued by the IMD whose objective is to alert people ahead of severe or hazardous weather which has the potential to cause damage, widespread disruption or danger to life. Warnings are updated daily.
The IMD uses 4 colour codes
Green (All is well): No advisory is issued.
Yellow (Be Aware): Yellow indicates severely bad weather spanning across several days. It also suggests that the weather could change for the worse, causing disruption in day-to-day activities.
Orange/Amber (Be prepared): The orange alert is issued as a warning of extremely bad weather with the potential of disruption in commute with road and rail closures, and interruption of power supply.
Red (Take Action): When the extremely bad weather conditions are certainly going to disrupt travel and power and have significant risk to life, the red alert is issued.
These alerts are universal in nature and are also issued during floods, depending on the amount of water rising above land/in a river as a result of torrential rainfall. For instance, when the water in a river is ‘above normal’ level, or between the ‘warning’ and ‘danger’ levels, a yellow alert is issued.
While this is the general interpretation of these colours, for more specific weather events such as rainfall, thunderstorm, lightning, etc these colours point out more warning.
How is the colour decided?
According to IMD, a special matrix is followed to decide the colour of weather situations. It is based on the “probability of occurrence of the event as well as its impact assessment”. The decision of the colour also depends on the meteorological factors, hydrological factors, geophysical factors that indicate the risk.
India Meteorological Department was established in 1875.
It is an agency of the Ministry of Earth Sciences of the Government of India.
It is the principal agency responsible for meteorological observations, weather forecasting and seismology.