Monsoon: Here's what green, yellow, orange, red alerts mean
Several parts of India—including Delhi, Himachal Pradesh, Uttarakhand, and Uttar Pradesh—are currently witnessing torrential rains and consequent floods or flood-like situations, leading to huge loss of life and property. As the death toll and the number of people stranded rise by the day, the India Meteorological Department (IMD) has predicted further devastation, issuing red, orange, and yellow alerts. Let's understand these color-coded warnings.
Green alert: No heavy rainfall, no advisory
If a green alert is issued, it means there might be a weather-related event but nothing worrisome. It does not require any special arrangements or advisories to be aware of. In the case of monsoon, this alert means that there could be rainfall of less than 70mm per hour in the area concerned. A green alert signifies no thunderstorms or duststorms.
Yellow alert: Heavy rainfall, be cautious
When a yellow warning is issued for a region, it means that it can experience heavy rainfall of up to 64.6mm to 115.5mm within 24 hours. It denotes bad weather conditions, with a risk that they may exacerbate with time and cause slight hindrance in daily commutation and other activities. Additionally, it signifies light thunderstorms with less than 40kmph wind gusts.
Heavy rain likely in Kerala, 3 districts on yellow alert
On Tuesday, IMD issued a yellow warning until Friday (July 14) in three districts of Kerala, Idukki, Kannur, and Kasaragod, as they are likely to receive a heavy spell of rainfall. There is a likelihood of wind speeds reaching 40-45kmph, with gusts up to 55kmph.
Orange alert: Very heavy rainfall, be prepared
An orange alert indicates very bad weather conditions that may even disrupt road, rail, and air modes of transport. It also includes disruption of power supply and cautions people to brace themselves for any sudden devastation. It signals 115.6-204.4mm of rain per 24 hours and moderate thunderstorms with 41-61kmph wind speed. Residents are asked to stay indoors. Shops, institutions, and offices are generally closed.
Orange alert issued in Delhi, parts of Himachal Pradesh
As the Yamuna River breached the danger mark of 205.33m on Monday, Delhi has been put on an orange alert. Several regions in Himachal Pradesh, including Una, Hamirpur, Kangra, and Chamba, are also on the same alert for the next 24 hours.
Red alert: Exceptionally heavy rainfall, take action
A red alert is issued when the weather conditions are extremely severe, which can cause potential damage to life and property. If the rainfall in an area is greater than or equal to 204.5mm per 24 hours, this color code urges people to take action to safeguard themselves. Residents are asked to evacuate from low-lying areas. It also signals severe to very severe thunderstorms.
7 districts in Himachal Pradesh are under red alert
Considering the current scale of destruction in Himachal Pradesh, the authorities have issued a red alert in districts including Solan, Shimla, Sirmaur, Kullu, Mandi, Kinnaur, and Lahaul-Spiti for the next 24 hours. A flash flood warning has also been issued for the same destinations.
Why are colors used to denote weather conditions?
As per the IMD, "Color codes are used in weather warnings for bringing out the severity of the weather phenomena expected." It considers several factors, including meteorological factors, hydrological factors, and geophysical factors, to issue a specific color. This helps warn disaster management authorities "about the impact of the weather expected to keep them ready for necessary action related to disaster risk reduction."
