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Roy, Soma Sen
- Catastrophic Heavy Rainfall Episode over Uttarakhand during 16-18 June 2013 - Observational Aspects
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Authors
Affiliations
1 India Meteorological Department, Lodhi Road, New Delhi 110 003, IN
1 India Meteorological Department, Lodhi Road, New Delhi 110 003, IN
Source
Current Science, Vol 107, No 2 (2014), Pagination: 234-245Abstract
Widespread very heavy to extremely heavy rainfall occurred over Uttarakhand and its neighbouring states during 16-18 June 2013, which caused flash floods, landslides, large-scale loss of lives and damage to property. The present study analyses the dynamical and thermodynamical features associated with this torrential rainfall episode. The analysis suggests that due to strong interaction between an oncoming midtropospheric trough in the westerlies and the strong lower-tropospheric southeasterly monsoon wind flow in association with a monsoon low-pressure system over the North Indian region, a lower tropospheric wind convergence zone developed over Uttarakhand and its neighbouring regions. A strong Bay of Bengal current of air with wind speed of 40 kts in the northern periphery of the monsoon low, pumped a lot of moisture into the region. Supported by strong orographic effect due to high terrain and strong moisture feeding from both the Arabian Sea and the Bay of Bengal, a large-scale quasistationary regenerative mesoscale convective system (MCS) developed over the zone of convergence. The episode was comparable to the 2010 Leh flash flood episode, in that the synoptic conditions were similar in both cases. However, while the Leh episode resulted from repeated surges of westward travelling MCS across the Tibetan Plateau, the present case was due to quasistationary regenerative MCS over the region.Keywords
Heavy Rainfall Episode, Mesoscale Convective System, Synoptic Features, Thermodynamic Features.Full Text
- A Location-Specific Nowcast and SMS-Based Dissemination System for Thunderstorm and Lightning Warning over Jharkhand, India
Abstract Views :189 |
PDF Views:97
Authors
Affiliations
1 Meteorological Centre Ranchi, Ranchi, Jharkhand 834 002, IN
2 India Meteorological Department, New Delhi 110 003, IN
3 Meteorological Centre Jaipur, Jaipur 302 029, IN
1 Meteorological Centre Ranchi, Ranchi, Jharkhand 834 002, IN
2 India Meteorological Department, New Delhi 110 003, IN
3 Meteorological Centre Jaipur, Jaipur 302 029, IN
Source
Current Science, Vol 120, No 7 (2021), Pagination: 1194-1201Abstract
Effective nowcasting for thunderstorms has been a challenge to operational forecasters in Jharkhand, India as lightning strikes-related deaths are significantly high. Extrapolation of radar echoes is the very foundation of nowcasting. Multiple radar mosaic data are able to pick out the size, shape, intensity, speed and direction of movement of individual storms on a continuous basis. This makes it possible to determine the likely location of a moving storm by extrapolation. This article demonstrates a new approach of locationspecific nowcast and SMS (short message service)- based dissemination system for thunderstorm and lightning warning up to 3 h ahead over Jharkhand. There are three components of the system. First, identification of the initial development and tracking of thunder cells by mosaic composite reflectivity data from multiple radars. The future location of thunder cells, and their growth or dissipation in terms of radius is estimated by extrapolation using their past trends. Secondly, based on this forecast information, an SMS is generated by the web-based GIS portal of Jharkhand Space Applications Centre for the forecast location and sent to the concerned state officials and mobile service providers over that region. Finally, the warning SMS is sent to all the active mobile users over that region at that time. The system combining nowcasting and dissemination of warning directly to the likely affected people is expected to be more robust considering its effectiveness in the reduction of human casualty.Keywords
Dissemination System, Lightning, Nowcast, Short Message Service, Thunderstorm.Full Text
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