Weather phenomena such as Extreme rainfall events, cloud burst, cyclone effects in coastal region, heavy rainfall, flood, fog in winter season, Cold waves, Heat waves and Norwesters etc. are primarily the main source of weather disaster to the loss of human lives and property. Various services to the public at large pertaining to various sectors like agricultural sector, aviation sector, health, traffic and civic services etc. do get severely affected due to adverse weather phenomena in a year. Further, the adverse weather systems cause hindrance in rendering rescue operations during or after an emergency. Therefore a proper disaster management encompassing Preparedness, Prevention and Planning need to be realized to combat the effects of the severity of weather systems in the country by issuing real time forecasting of the weather systems and their timely & efficient dissemination to the public at large. By now we have studied various weather phenomena occurring in different parts of the country since last more than century and also have clearly understood the role and their effects on different sectors that render the services to the public at large. The time is the vital to prepare ourselves against severe & extreme weather phenomena like Hale, Wind, Flood, Cyclone, Air pollution, Draught, Heat wave, Cold wave, Fog, Frost and Fire spread etc. based on timely forecast issued from time to time. Weather related hazard is summarized in Table below to have an explicit understanding with regards to various important parameters such as developing time of the event, time of occurrence, Spatial extent and number of people affected corresponding to occurrence of any specific weather, which in turn provides an intuition to adopt necessary action in the line of prevention from the weather phenomena to mitigate the future disaster.
|Weather||Development Time||Occurrence Time||Spatial Extent||People affected|
|Wind||Fast||Short||Small to medium||Small|
|Flood||Slow to fast||Short to long||Medium to large||Medium|
|Draught||Slow to fast||Long||Medium to large||Large|
|Cyclone||Medium||Medium to long||Medium to large||Medium to large|
|Heat wave||Medium||Medium to long||Medium to large||Large|
|Cold wave||Medium||Medium to long||Medium to large||Large|
|Fog||Fast||Short||Small to medium||Small to medium|
|Frost||Fast||Short||Small to medium||Small to medium|
|Air pollution||Medium||Medium to long||Medium to large||Medium to large|
|Fire spread||Fast||Short to long||Small||Small to medium|
1. Time for event to develop and duration of occurrence. All of these events vary widely in time developing and length of time occurring. A tornado develops quickly and seldom lasts more than a few minutes. In contrast, droughts are the slowest developing weather hazard, but also the longest lasting. Flash floods can develop in a few minutes and be over in a few minutes, but the damage has been done.
2. Spatial extent or size of area impacted. Such events vary dramatically in their spatial extent. A microburst might be the most localized of weather related events while droughts, floods and pestilence can affect a large region of the globe. A lightning strike might be as localized as an event can get, and, yet set off wild fires destroying thousands of acres.
3. Potential number of people impacted. There are dramatic differences in the number of people that might be affected. A tornado may be a localized, short-lived event, but, it can affect thousands of people if it hits a city.
The preparedness against the above described weather phenomena could be adhered with the efficient forecasting and timely dissemination of information to the public and the authorities involved in disaster management activities. Proactively, based on the understanding on meteorological science with regards to all weather phenomena and their short and/or long term forecast would pave the way for authorities to get prepared to combat the weather emergencies in different parts of the country in different seasons.
Planning to combat the weather disaster is essentially used for reactive measure on occurrence of any severe weather, but need to be arranged well with proper planning in advance to minimize the time lapse if exercised right during the event. Groups of efficient and trained rescue teams are arranged by the authorities for any such weather hazards. The main focus lies with quick and efficient rescue operation in order to save human lives and properties on occurrence of extreme events
As on date the Department is successfully associated with the short and long term forecasting of various weather phenomena and their dissemination to the public at large and various Government agencies for further use of the weather information for direct societal use. Once we are at the stage of completing the preparedness part against the severe and extreme weather phenomena, now is the step we need to take appropriately to prevent our people and property from unwanted catastrophic losses by adopting systematic preventive approach. Our disaster management authority is sincerely involve in circulating information pertaining to atmospheric phenomena and their respective dos and don’t to common people in order to cope with any unforeseen adverse situations arising due to severe weather happening. Severity associated with specific weather systems and steps involved in understanding the hazard associated well in ahead through forecasting and dissemination system are detailed below categorically-
A tornado is a violently rotating column of air that is in contact with both the surface of the earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. They are often referred to as twisters or cyclones, although the word cyclone is used in meteorology, in a wider sense, to name any closed low pressure circulation. Tornadoes come in many shapes and sizes, but they are typically in the form of a visible condensation funnel, whose narrow end touches the earth and is often encircled by a cloud of debris and dust. Most tornadoes have wind speeds less than 110 miles per hour (177 km/h) and travel a few miles (several kilometers) before dissipating. The most extreme tornadoes can attain wind speeds of more than 300 miles per hour (483 km/h), stretch more than two miles (3.2 km) across, and stay on the ground for dozens of miles (more than 100 km).
A cyclone is an area of closed, circular fluid motion rotating in the same direction as the Earth. This is usually characterized by inward spiraling winds that rotate anti-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere of the Earth. Most large-scale cyclonic circulations are centered on areas of low atmospheric pressure. The largest low-pressure systems are cold-core polar cyclones and extratropical cyclones which lie on the synoptic. Warm-core cyclones such as tropical cyclones and subtropical cyclones also lie within the synoptic scale. Mesocyclones, tornadoes and dust devils lie within the smaller mesoscale. Upper level cyclones can exist without the presence of a surface low, and can pinch off from the base of the Tropical Upper Tropospheric Trough during the summer months in the Northern Hemisphere. Extratropical cyclone form as waves in large regions of enhanced mid-latitude temperature contrasts called baroclinic zones. These zones contract to form weather fronts as the cyclonic circulation closes and intensifies. Later in their life cycle, cyclones occlude as cold core systems. A cyclone's track is guided over the course of its 2 to 6 day life cycle by the steering flow of the cancer or subtropical jet stream.