GS Paper 1
Syllabus: Geography- a geophysical phenomenon
Source: Indian Express
Context: Hurricane Ian strengthens as Cuba and Florida brace for impact.
As Earth’s climate warms, more storms are undergoing this kind of rapid intensification, growing quickly from relatively weak tropical storms to Category 3 or higher hurricanes in under 24 hours, sometimes stunning forecasters and giving residents little time to prepare.
How climate change can rapidly intensify tropical storms:
- Warming oceans fuel higher winds: More than 90% of the excess heat from human-caused global warming over the past 50 years has been absorbed by the oceans.
- Winds intensify more rapidly: Rapid intensification technically refers to an increase of at least 30 knots, or 35 mph, in the maximum sustained winds over a 24-hour period, according to the National Hurricane Center.
- Several elements other than ocean temperatures affect hurricanes: One of those elements is vertical wind shear or a measure of how much the wind changes in speed or direction at increasing heights in the atmosphere.
- Strong vertical wind shear can inhibit the development of hurricanes by tilting the structure of a storm and by forcing cool, dry air into its core.
The increase in the number of hurricanes that intensify quickly and unpredictably presents a sticky problem for forecasters, whose assessments can affect a community’s preparedness.
Weather warnings:
The top weather body in India, the Indian Meteorology Department (IMD) is tasked with identifying and issuing warnings for adverse weather events, relying on a system of colour-coded weather warnings to do so.
The IMD’s four colour codes are:
- Green (pre-cyclone watch): This code means that “all is well”, there is no likelihood of any adverse weather-related and there are no advisories issued.
- Yellow (cyclone alert): The colour yellow signals authorities to “be aware” or on their guard, with the likelihood of severely bad weather that could last several days at a stretch, while also suggesting that the weather could take a turn for the worse and upset daily activities.
- Orange (Cyclone warning): Meaning “Be prepared”, the IMD issues the orange alert as a warning for extremely bad weather, electricity blackouts and the possibility of communication disruptions, including road and rail closures.
- Red (during or post-landfall outlook): The IMD issues the highest level of warning—indicating authorities should “take action”—only when it is guaranteed that bad weather is going to upend travel and power and pose a significant risk to life.
These warnings are based on ‘the probability of occurrences and ‘impact assessment’.
The point of the exercise is to give authorities and people likely to be impacted enough forewarning to be prepared to meet harsh or hazardous weather that has the potential to wreak severe damage, disrupt daily life or cause loss of life. The warnings are updated daily.
Mains Link
Q. Discuss the meaning of colour-coded weather warnings for cyclone-prone areas given by the India’s Meteorological department. (Answer in 150 words) (UPSC Mains 2022)
