Extraordinary high intensity and very localized rainfall of 29Aug2023 at Kalimpong

Meteorological conditions
28Aug2023 was a cloudy day and except for a little early morning rain, it was dry in Kalimpong. We even had a rare 'NO WARNING' for Sub-Himalayan West Bengal (SHWB) and Sikkim.

Cloud images showed fairly settled weather in our region through the day - even until 8.15pm on 28Aug2023, when I put a last post in 'Hazard Alerts' our What's App 'Early Warning' group in the Darj-Sikkim region.

                  Above image shows no major clouding in the area circled.

The clouding suddenly increased thereafter, as seen in the IR Image of 11.45pm of 28Aug2023:

              Notice the clouding which has suddenly appeared below Kalimpong

Nowcast issued by IMD is placed below

Rainfall of 29Aug2023 morning
We had sudden and very intense rainfall starting from 1.30am with peak intensities crossing 135mm/hr. The rainfall amount was 79.2mm in a very short time.

The screenshot of Damini (Lightning Alert app) showing no lightning at 3.06am in our area is below

And at 3.45am, with the rainfall declining over Kalimpong, the clouding vanished, just as quickly as it had appeared.

What is amazing in this event, besides the extremely sharp increase and decrease of rain intensity, is that it rained only over Kalimpong.
Adjoining towns of Darjeeling, Kurseong and Todey (where there are Davis automatic weather stations) had ZERO rainfall

QUESTION IS:
ARE WE PREPARED FOR THIS TYPE OF RAINFALL WHICH IS NO LONGER EXTRAORDINARY BUT BECOMING THE NEW NORMAL?

Praful Rao
Kalimpong district
Darjeeling-Kalimpong Himalaya
savethehills@gmail.com
9475033744

 

Rainfall data (July2023) of some towns in the Darjeeling-Sikkim Himalaya.

In July2023, the monsoon advance and covered the entire country.

Quite clearly:

• Rainfall was deficient in Darjeeling, Kalimpong and even Kurseong region. All three towns had very little rain in the latter half of July2023.
  
• The foothills of Kalimpong district, ie Gorubathan, Jaldhaka, Mangzing, Jholung had a huge surplus in rainfall.
  
• Gangtok and Mangan also had excess rainfall, whereas Dentam went severely deficient.
  
• As such, the towns in the plains ie Jalpaiguri and Siliguri had significantly more rainfall compared to the hill towns.
  
  
  Praful Rao,
  Kalimpong district,
  Darjeeling-Sikkim Himalaya
  savethehills@gmail.com
  9475033744
  

Mapping rainfall in our region: NEW (DAVIS) AWS at Todey Village in Kalimpong station and location of Automatic Weather Stations (DAVIS) and Manual Rainfall Gauges.

STH has been monitoring rainfall in our region for many years now and we publish these records each month in this blog. 

The above map shows the location of 6 DAVIS AWS in our region which will give real time weather information 24 X 7 and also the location of 4 manual rainfall gauge stations.
Real time weather includes

• Temperature (outdoor and indoor, max and min temp, graphical data)
• Rain (current rain, 24hrs rain, monthly rain, yearly rain, intensity of rain in mm/hr)
• Wind data ( 10min average, gusts and graphical data)
• Barometric pressure (& graphical representation of variation)
• Weather forecast.
  

How to get real time weather from the AWS
In order to get the real time weather from the 6 DAVIS AWS stations:

• Download and install the 'WEATHERLINK Davis Instruments' app from Google play store.
• You may have to register.
• Search for Davis weather stations in Kalimpong, Gangtok and so on and save them.
  
  
  Praful Rao
  Kalimpong district
  Darjeeling -Sikkim Himalaya
  9475033744
  savethehills@gmail.com
  
  
  

January 2021 rainfall of the region

Praful Rao and Shreya Gurung
Kalimpong district
Darjeeling Sikkim Himalaya

Rainfall data of some town in the Darjeeling- Sikkim Himalayas (Oct2020) - GOING RED ALL THE WAY

 The OCT2020 saw some really hectic weather activity in the Bay of Bengal, the Darjeeling-Sikkim Himalaya escaped this and except for North Sikkim which recorded above average rainfall, all other towns had deficient rainfall.

The rainfall stats from IMD are shown below:-

The sudden and sharp change from 'Large Surplus' rainfall in Sep2020 to 'Deficient' rainfall in Oct2020 is seen below:

With the numerous storms in the Bay of Bengal in Oct 2020, the withdrawal of the SW Monsoons from this region was delayed.

Collection and tabulation of rainfall data : Ms Shreya Gurung

Praful Rao
Kalimpong district,
Darjeeling- Sikkim Himalaya

A pictoral record of the landslides of JUN 2020 in Darjeeling-Sikkim Himalaya

Shown above are the approx timelines when due to the more than normal rainfall in Jun2020, there were numerous landslides in the Darjeeling - Sikkim Himalayas and all occurred during periods of heavy rain. For example, in 6 days (17Jun-22Jun2020) Kalimpong received approx 78% of its monthly rainfall which is when all the landslides in Kalimpong took place.
More specifically:
a. Darjeeling and Kurseong area had landslides just as the SW monsoons entered the region on 12/13Jun 2020. Many of these landslides are documented here.
b. Kalimpong district which had almost no rain during this onset period, had intense rain on 17Jun which triggered a number of slides in the district.
c. Mangan (N Sikkim) and E Sikkim were the only places which had surplus rain over the winter months and continued to have very heavy rain towards June end and that triggered a number of landslides.
In order to maintain a record of the landslide events I am posting verified photos of some of them as submitted by HA members.

Kalimpong:

North Sikkim (Passingdang)

North Sikkim (District HQ: Mangan)27.4979° N, 88.5348° E

North Sikkim (Barfok)
27.509787°N, 88.437531°E

Debris Torrent as seen from across the Teesta from Mangan. No loss of lives, some houses evacuated.

Landslide at NHPC Stage V 510 MW Dam at Dikchu, East Sikkim

Landslip on Dhotrey- Maneybhanjang road (22Jun2020?)

Rimbick- Lodhoma landslide (28Jun2020)
at Chota Hatta, Kankeybong.

Breaches on NH55 (Siliguri to Darjeeling) near Pagla Jhora (Kurseong)
30Jun2020

My sincere thanks to all those who have volunteered their time and effort in 'HAZARDS ALERTS' (Whats App group)  and elsewhere to provide the information and photographs for the above record.

Praful Rao
Kalimpong district
Darjeeling Sikkim Himalaya

Rainfall data of some towns in Darjeeling -Sikkim Himalaya: Mar2020

Data of Sikkim is from IMD

Thanks Shreya for all your help

Praful Rao,
Kalimpong district
Darjeeling - Sikkim Himalaya

Rainfall data of some towns in Darjeeling-Sikkim Himalaya: Jan2020

Data of Sikkim is from IMD

Thanks Shreya for yr help :)

Praful Rao
Kalimpong district
Darjeeling-Sikkim Himalaya

Rainfall data of Darjeeling-Sikkim Himalaya - Apr2017

Synopsis of April weather.
We had the first cyclone of the year (Maarutha) brewing up in the Bay on 16Apr2017 but as predicted it affected Myanmar and a few north eastern states.
We had quite of lot of hailstorm activity in the region but no major damage was reported. We also published a mid-month bulletin on precipitation here.
A major landslide in Shimla caused quite a lot of sensation since a detailed video was uploaded on Youtube.

All maps are from IMD.

Praful Rao,
Kalimpong district,
Darjeeling-Sikkim Himalaya

Rainfall data Aug2014

IMetD clamped a 'heavy rainfall warning' in the Sub-Himalayan West Bengal (SHWB) and Sikkim region for much of Aug2014 even though there was no major activity in the Bay of Bengal (we plotted two low pressure areas 1 and 2, during the month).
In Kalimpong, we experienced some of the soggiest and damp days thus far in 2014 even as the periods of heavy rainfall was limited to just 3 days.
The heaviest rainfall during Aug2014 was along the plains of Dooars and even Siliguri with the mountainous region receiving considerably less rain.
There were no reports of major landslides in this region.

Praful Rao,
Kalimpong,
Dist Darjeeling

Rainfall data of Darjeeling district and N Sikkim - April 2013

The pre-monsoon season in India lasts from Mar- May and as per the above map from IMetD we are running deficient in rainfall.
STH has installed a new ARG in Mangan (N Sikkim) but regretfully the ARG at Jaldhaka in the foothills of the Dooars has become unserviceable.

Praful Rao,
Kalimpong