Deadly storms in Northern India

Deadly storms in Northern India

02 May 2018 00:00–23:00 UTC

Deadly storms in Northern India
Deadly storms in Northern India

A very intense Mesoscale Convective System (MCS), with induced dust, was responsible for many casualties in the Uttar Pradesh province of Northern India in early May.

Last Updated

22 October 2020

Published on

02 May 2018

By Ivan Smiljanic (SCISYS)

Although media reports named the event as ‘dust storms’, and satellites did identify dust in the region, the high intensity of the associated MCS were responsible for more than 100 deaths in the region.

Very rapid development of the convective system occurred around 300 km west of New Delhi, along a eastward advancing dust field front, as can be seen in the Meteosat-8 Dust RGB animation (Figure 2). Its movement was likely enhanced by the cold outflow from an older convective system in the north. Dust sources were situated further west, mostly in Pakistan and Iran.

Very peculiar cirrus outflow, that looked like splayed fingers, on top of associated MSC (Figure 1) is connected to the gravity wave field, excited by a squall line perpendicular to the system propagation.

 Himawari-8 10.4  µm, 2 May 19:50 UTC
Figure 1: Himawari-8 10.4 µm, 2 May 19:50 UTC
 
Figure 2: Meteosat-8 Dust RGB animation, 2 May 00:00 UTC–14:00 UTC

The system intensified as it travelled to the south-east along the low level moisture boundary, throughout most of Northern India, before dissipating in the early hours of the following day, as can be seen on the Himawari-8 10.4 µm animation (Figure 3).

Figure 3: Himawari-8 10.4 µm animation, 2 May 08:00 UTC–23:00 UTC

The strong intensity of this system is demonstrated by its size and duration, the number and variety of cloud-top features (e.g. multiple overshooting tops), and the low cloud top temperatures (exceeding -75 °C).

This was well captured by the by the visible (nominally 500 m) and high resolution infra-red (2 km) imagery from the Himawari-8 ABI instrument, see Figures 4 and 5.

Figure 4: Himawari--8 0.6 µm animation, 2 May 00:00 UTC–13:45 UTC
 
Figure 5: Himawari--8 0.6 µm & 10.4 µm animation, 2 May 08:00 UTC–13:45 UTC

Due to the fact that the event took place close to the edge of the ABI instrument scanning area, one needs to keep in mind reduced scanning resolution, but also take into account angle correction which greatly affects high-reaching clouds (parallax correction), and scattering processes in the visible spectrum — in this case strong forward scattering for AHI and weak backward scattering for SEVIRI in the local evening hours (Figure 6).

 
 Illustration of the scanning view of both satellites
Figure 6: Illustration of the scanning view of both satellites
 

The difference in viewing angles between Meteosat-8 and Himawari-8 is obvious when directly comparing images from both on the same grid Figure 7). When viewing the features at an angle, these two satellites are seeing clouds and other features (e.g. overshooting tops) from almost opposite sides.

Image comparison

Himawari-8 0.64 µm at 500 m compare1
compare2
 

Figure 7: Comparison of Himawari-8 ABI and Meteosat-8 SEVIRI images

The zoomed-in views over New Delhi (ca. 10 km radius) (Figures 8 and 9) reveal the distorted pixel shapes from both satellites (at the same projection). Change in pixel size, from sub-satellite point, is following: for the ABI instrument from 2 x 2 km to ca. 4.95 x 7.65 km (lat/lon); for SEVIRI instrument from 3 x 3 km to ca. 4.20 x 4.25 km. For easy reference one pixel is marked in both images.

 Met-8, 02 May, 09:20 UTC
Figure 8: Met-8, 02 May, 09:20 UTC
Dust RGB (zoomed-in)
 Himawari-8, 02 May, 09:50 UTC
Figure 9: Himawari-8, 02 May, 09:50 UTC
10.4 µm (zoomed-in)

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India dust storms: More than 100 killed in Uttar Pradesh, Rajasthan (BBC News)