An Assessment of the Impact of Local Convective Storms during Premonsoon season over Eastern

D. Lohar1*, S. Dalal1, S. Sarkar1 and Sangeeta Kundu2

1Atmospheric Science Research Group Department of Physics, Jadavpur University, Kolkata-700 032 2 Department of Economics Jadavpur University, Kolkata-700 032

* Dr. Debasish Lohar Co-Principal Investigator of MICRODIS-JU project Department of Physics, Jadavpur University, Kolkata-700 032, INDIA e-mail: [email protected] An Assessment of the Impact of Local Convective Storms during Premonsoon season over Eastern India

Layout of the presentation

¾Hierarchy of disaster categories

¾Study area

¾Mesoscale Convective Systems (MCS) /premonsoon thunderstorms of

¾Data and analysis

¾Concluding remarks. Hierarchy of disaster categories Disaster Disaster Disaster Disaster Disaster Generic Group Group Main-Type Sub-Type Sub-sub-Type

Natural Disaster Geophysical Earthquake Ground shaking Volcano Tsunami Volcanic eruption

Meteorological Storm Tropical storm Extra-tropical storm Local/Convective Thunderstorm Storm Sandstorm Tornado Orographic storm

Hydrological Flood General river flood Flash flood Storm surge

Climatological

Biological

Extra-terrestrial

Adapted after Regina Below, Angelika Wirtz and Debarati Guha-Sapir, 2009: Disaster Category classification and perpil Terminology for operational purposes. Working paper no. 264 Study area

AWS stations •Jhalda • Purulia • Raghunathpur • • • • Bishnupur AWS site locations • Santiniketan Data used in the present study

1. Wind and temperature data from Automatic Weather Station (AWS)

2. Print media reports

3. Doppler Weather Radar (DWR) Imageries

(March through May, 2008) Vertical Cross Section View Doppler Weather Radar image of a thunderstorm cell Doppler Radar Image of MCS Temperature and wind speed during the passage of convective storm on 8th May, 2008 as recorded by a weather station located at Bishnupur, in the district of , West Bengal.

a (a) Duration of MCSs 5 4.32

4

3 (b) Gust Wind speed 1.91 2 Time in hours

1

0 Average duration Standard deviation

47.8 b

50

40

30

20

Wind speed inKm/hr 6.7

10

0 Average MCS wind speed Standard deviation Damages caused by MCSs over study area

a. Damages to property due to strong wind gust b. Damages to crops due to hail storms c. Loss of human lives due to lightning, hailstorms, collapsing of houses d. Disruption of transportations

Assessment of the impact and estimation of the damages need micro-level studies Distribution of death cases resulting from different causes associated with MCSs.

a

Death toll due to lightning Death toll due to 15 collapsing house, brick, tree 29

Death toll due to hailstorm 3 b March 3

May April 23 21 Concluding Remarks

Considering the severity, frequency of occurrence and damages caused by Mesoscale Convective Systems (MCS) over eastern India, MCS may be considered as an important natural disaster

In order to have a complete assessment of the impact of such disaster event from the socio-economic point of view needs micro-level surveying and MICRODIS could be a right forum to carry out the investigation