STH stormwatch : LOW pressure in the Bay of Bengal.

SaveTheHills Stormwatch is a series where we track and report on significant weather developments in our region not only to forewarn our communities (which we largely do today through our WhatsApp Group 'Hazard Alerts 1& 2') but keep a record of the event.
As on 20Oct2023, a low pressure formed in the central Bay of Bengal which is likely to intensify into a depression by 22Oct and move towards the Bangladesh and West Bengal coasts by 24Oct2023.
The Darjeeling-Sikkim region has just seen catastrophic flooding and destruction in the 04Oct2023 GLOF from South Lhonak glacier and being located barely 600kms from the Bay of Bengal any major storm in the north Bay will probably impact our region and which would hamper all reconstruction activities and make lives of those who have lost everything even more difficult.

 

Update on 22Oct2023

IMD has posted to its first forecast track (above) on the probable path of the storm

Update 24Oct2023: Cyclone 'HAMOON' is born
JTWC's forecast track

IMD latest forecast track

Kolkata reported moderate rainfall for sometime on 23Oct2023, but largely the storm seems to be keeping clear of the city.

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

STH stormwatch: A cyclone to threaten India's financial hub in the midst of a pandemic

JWTC forecast on the storm in the Arabian sea

Excerpt from IMD forecast

'The Well Marked Low Pressure Area over Southeast & adjoining Eastcentral Arabian Sea and Lakshadweep area concentrated into a Depression over Eastcentral & adjoining Southeast Arabian Sea. and lay centred about 400 km southwest of Panjim (Goa), 700 km south-southwest of Mumbai ( Maharashtra) and 930 km south-southwest of Surat (Gujarat).
It is very likely to intensify into a Deep Depression over Eastcentral & adjoining Southeast Arabian Sea during next 12 hours and intensify further into a Cyclonic Storm over Eastcentral Arabian Sea during the subsequent 24 hours. It is very likely to move nearly northwards initially till 02nd June morning and recurve northnortheastwards and cross north Maharashtra and south Gujarat coasts between Harihareswar (Raigarh, Maharashtra) and Daman during evening/night of 03 rd June,2020.'

 

Like AMPHAN hitting Kolkata on 20May2020, this storm too comes at a time when Mumbai has the highest rate of COVID19 infections in the country and is under lockdown.

UPDATE 1

It is still a Depression but will be called Cyclone 'Nisarga', when it intensifies into a cyclone. It is amazing how two consecutive megastorms (Cyclone 'Amphan' and this one) are targeting two megacities (Kolkata and Mumbai), this one with a population of 20 million and both in the midst of a pandemic.

UPDATE 2

The deep depression has now become a cyclone (NISARGA)  and while the track on the latest RSMC bulletin remains the same as earlier, information on the wind speeds and storm surge is as above.

UPDATE 3

First warning from JTWC has finally been issued.

Update 4

JTWC issued only 4 warnings for Cyclone Nisarga. The fourth and the last is below:

Rainfall records

Nira devghar,Pune dist - 147mm

Panshet,Pune dist - 137mm

Mahabaleswar - 214mm

Koyna Nagar - 156mm

Bhimashankar,Pune dist - 117mm

Khandala - 88mm

Praful Rao
Kalimpong district
Darjeeling-Sikkim Himalaya

STHstormwatch : Forecast tracks of storm in the Bay of Bengal (May2017)

Source

Praful Rao,
Kalimpong dist,
Darjeeling-Sikkim Himalaya

STH Stormwatch : Cyclone 'Maarutha' is born (16Apr2017) and its early demise (Update of 17Apr2017)

The storm in the Bay of Bengal intensified into a full blown cyclone and was christened 'MAARUTHA' today. This is the first named storm of the 2017 Northern Hemisphere Tropical Cyclone season.

Update of 17Apr2017 (Extracts from JTWC bulletin)
' SATELLITE IMAGERY SHOWS THE SYSTEM HAS MADE LANDFALL NEAR TOUNGUP AND IS RAPIDLY DECAYING.'
JTWC has also issued its final warning on the cyclone considering it no longer significant.

Praful Rao,
Kalimpong district,
Darjeeling-Sikkim Himalaya

STH Stormwatch : The FIRST storm of 2017 (in the Bay of Bengal)

Location of Low pressure area is approximate

Update from JTWC  (1330h / 14Apr2017)
JTWC has upgraded the warning from LOW to MEDIUM and extract is reproduced below :-
'GLOBAL MODELS ARE IN AGREEMENT ABOUT THE SYSTEM CONTINUING TO DEVELOP RAPIDLY AND TRACK TO THE NORTH-NORTHEAST. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.'

Update of 15Apr2017 (JTWC)

Update of 15Apr2017 (IMD)IMD has categorized the storm as a DEPRESSION now (morning inference) and forecasts the storm to intensify further into a deep depression and move towards the north Myanmar coast in the next 72hrs


Praful Rao
Kalimpong district,
Darjeeling-Sikkim Himalaya

STH Stormwatch : Low Pressure in Bay of Bengal (01Nov2016) and update (04Nov2016)

The system has intensified into a depression and is expected eventually become a cyclone.

Praful Rao
Kalimpong,
Dist Darjeeling

STH Stormwatch : Depression in the Bay of Bengal (21Oct2016)

Updates will be posted as necessary

Update 1 (JTWC IR image of two storms in our region)

Predicted storm track (shown in RED) is an approximation (NOT accurate!).

Update 2 (23Oct2016)

Update 3 (23Oct2016) - IMD predicted track

 
Praful Rao,
Kalimpong,
Dist Darjeeling

STH stormwatch (10Aug2016) : Depression in the Bay of Bengal intensifies into a deep depression and moves inland

Aug2016 has seen the development of at least 2 low pressure areas in the first week, in the Bay of Bengal. Both formed off the coast of Odisha and moved inland on an almost northwesterly track.
Extract of 'Inference' of 10Aug2016 (evening) for the depression above is below :-
'The deep depression over south Bangladesh & adjoining West Bengal moved north­
northwestwards during past 3 hours and lay centred at 1430 hours IST of today i.e. 10th August, 2016, over Bangladesh ; neighbourhood with its centre close to Latitude 23.4°N and Longitude 89.1°E, about 60 km east of Krishnanagar (West Bengal),40 Km southeast of Chuadanga (Bangladesh). The system is likely to move slowly north­northwestwards during next 24 hours. Subsequently,it is likely to weaken gradually and move west­northwestwards.'

Praful Rao,
Kalimpong,
Dist Darjeeling

STH Stormwatch (Update) : Storm tracks from JTWC and UK Met Office

 

Update on 18May2015 (Midday)
IMD has upgraded its category of the storm from 'Depression' to 'Deep Depression'

Link to JTWC image
Link to UK Met office storm tracker
Link to IMD Weather Warning

Praful Rao,
Kalimpong,
Dist Darjeeling 

STH Stormwatch (Updates) : The well marked low pressure area concentrates into a depression

Yesterday's well marked low has concentrated into a depression situated approx 240km SSE of Chennai. The system is likely to move NNW during next 12 hours and northwards thereafter along north Tamil Nadu and south Coastal Andhra Pradesh coast and likely to further intensify into a Deep Depression during next 48hrs - IMD
Update1 (All India Weather Inference of IMD- Evening).
The system is likely to move NNW towards north Tamil Nadu­/south Andhra Pradesh coast and further intensify into a deep depression during next 24 hours.
The system is likely to be close to Chennai during morning hours of 18May. It will move northwards and then recurve NNE and may intensify into a cyclonic storm during subsequent 24 hours.
(Italics are mine)

Praful Rao
Kalimpong,
Dist Darjeeling

STH Stormwatch (2016) :- First Low Pressure Area (LOPAR) of the year forms in the Bay (and updates)

Excerpt of IMD Weather Inference of 14May2016 (Night)

"A low pressure area has formed over equatorial Indian Ocean and adjoining southwest Bay of Bengal. It is likely to become well marked low pressure area and further concentrate into a depression during next 48 hours."

Websites and Links for watching/tracking severe weather  
1. Satellite images from IMD : IR and other images are available from IMD including animations. The images are updated every 30mins.

2. Cyclones in the Northern Indian Ocean :- see here

3. JTWC for tracks and images :- see here

4. Updated IR Imagery for aviation :- click on ICAO Area 'E' 
5. Worldwide Lightning location network :- Indicates lightning ie severe weather locations
6. STH stormwatch ie this blog.

Update 1 (15May2016- evening)
The above system has concentrated into a well marked LOPAR. It is likely to move northwestwards, become a deep depression and cross the Tamil Nadu coast between around 17May2016 (morning) - source

Praful Rao,
Kalimpong,
Dist Darjeeling

STH Stormwatch (26Nov2015) - Another low expected in the Bay of Bengal

Low expected to form in the next 24hrs and most probably Tamil Nadu will get another bashing.

Praful Rao,
Kalimpong,
Dist Darjeeling

STH stormwatch : Low Pressure forms in the Bay of Bengal - 07Nov2015

A Low Pressure Area has formed in the Bay of Bengal and as per IMD, it is likely to intensify into a well marked low pressure and then become a depression in the next 48hrs.

UPDATE on the storm (2100hrs) on 07Nov2015
IMD has upgraded the storm from a 'Low' to a 'Well Marked' low pressure area which will intensify into a depression in the next day or so

 UPDATE on the storm 08Nov2015

Track of storm is from JTWC

UPDATE (2) on the storm 08Nov2015
IMD has upgraded the storm from a 'well marked low' to a 'depression' in their midday weather bulletin. 
For anyone interested to check Chennai weather live see here 

UPDATE on the storm 09Nov2015

UPDATE (2) on the storm 09Nov2015
The depression intensified into a deep depression and crossed north Tamil Nadu coast at
7.30pm

UPDATE (last)  on the storm 10Nov2015 (evening)
The depression has moved inland and has weakened into a low pressure area and lies north of Tamil Nadu.



Praful Rao,
Kalimpong,
Dist Darjeeling

STH Stormwatch (25Jul2015) : Low pressure forms in NE Bay of Bengal. (UPDATED 27July2015)

South Bengal has been getting unusually heavy rainfall over the last fortnight or so, unfortunately there seems to be more rainfall in the offing with a low pressure forming in approx the area circled. The low pressure will intensify into a depression soon as per IMD's 'All India Weather Summary and Forecast Bulletin' issued on 25July2015 (night).

Praful Rao
Kalimpong,
Dist Darjeeling

Update 1.
As per All India Weather Inference (2000h, 26Jul2015 - Sunday)
The Low Pressure has intensified into a depression and may concentrate further into a deep depression. It moved westwards and is now close to Khepupara (Bangladesh). Likely to remain stationary there for some time.

 

Update 2 (27Jul2015)

The depression has remained stationary and likely to remain so for some time. It may intensify into a deep depression

STH stormwatch (31Dec2014) : Update on well marked Low Pressure Area in Bay of Bengal

Praful Rao,
Kalimpong,
Dist Darjeeling

STH Stormwatch (27Dec2014) : Reporting a well marked low in south Bay of Bengal

The well marked low pressure is expected to intensify into a depression in the next 48hrs

Praful Rao,
Kalimpong,
Dist Darjeeling

STH Stormwatch : Cyclone formation alert in the Arabian sea

IMetD is reporting a well-marked low pressure (see IR image on top of 6.30am today) in the south eastcentral Arabian sea, which is likely to intensify into a cyclone in the next 48h.
JTWC tracks are shown below.
It is amazing that a storm brewing so far away can spew clouding which is affecting us today - as I write it is turning cloudy in the Darjeeling-Sikkim Himalaya (see cloud trail in the IR image on top)

Praful Rao,
Kalimpong,
Dist Darjeeling

STH Stormwatch 07Oct2014 : the first cyclone in Bay of Bengal of 2014?

Excerpt from IMetD
'The well marked low pressure area over north Andaman sea and neighborhood has concentrated into a Depression and lay centred at 0830 hours IST of today, near lat.11.5°N / long 95.0° E, about 250 km east of Port Blair.
It would move in a west­ northwesterly direction and intensify into a deep depression within 24 hours and further intensify into a cyclonic storm thereafter.'


Updates and tracks of the storm will be posted as required.

Praful Rao,
Kalimpong,
Dist Darjeeling.

STH storm watch (27Aug2014) : Low pressure forms in the Bay of Bengal

After a quiescent period stretching almost the entire month of Aug2014, when there was virtually no activity in the Bay of Bengal, IMetD is reporting the formation of a low pressure area in the " west central and adjoining north west Bay of Bengal off north Andhra Pradesh­ south Odisha "
We will post updates as necessary.


Praful Rao,
Kalimpong,
Dist Darjeeling

STH Stormwatch (03Aug2014) : Another low pressure area in the Bay of Bengal

Excerpt from  IMD's All India Weather Bulletin (Sunday 03Aug2014)
"A low pressure area has formed over north Bay of Bengal and neighbourhood. Associated upper air cyclonic circulation extends upto 7.6 km above mean sea level. It would become well marked low pressure area during next 24 hours"

Updates will be posted as required.

Update on 04Aug2014
"The well marked low pressure area over Gangetic West Bengal and neighbourhood concentrated into a Depression and lay centered at 0830 hours IST of today the 04th August 2014 over Gangetic West Bengal and is close to Midnapur. It would move west­northwesterly direction during next 24 hours and weaken gradually."

Praful Rao,
Kalimpong,

Dist Darjeeling.