No. RMCKOL-13020/4/2025-RWFC-KOL Date: 25.07.
2025
Time: 1330 Hrs IST
Special Bulletin: 10
Subject: The Depression over coastal West Bengal and adjoining areas of Northwest Bay of
Bengal & Bangladesh.
The Depression over Northwest Bay of Bengal and adjoining areas of coastal West Bengal and
Bangladesh moved west-northwestwards with a speed of 13 kmph during past 3 hours, crossed
West Bengal & adjoining Bangladesh coasts between 0730 and 0830 hrs IST and lay centred at 0830
hrs IST of today, the 25th July over coastal West Bengal and adjoining areas of Northwest Bay of
Bengal & Bangladesh, near Lat. 21.7°N and Long. 88.8°E, about 150 km west-southwest of
Khepupara (Bangladesh), about 60 km south-southeast of Canning (West Bengal), 80 km east of
Sagar Island (West Bengal) and 100 km south-southeast of Kolkata(West Bengal). It is very likely to
move west–northwestwards across Gangetic West Bengal and adjoining North Odisha and
Jharkhand during next 24 hours.
The monsoon trough at mean sea level now passes through Jammu, Chandigarh, Bareilly,
Gorakhpur, Patna, Bankura, Kolkata, center of Depression over northwest Bay of Bengal and
adjoining areas of coastal West Bengal and Bangladesh.
Under influence of the above systems, widespread light to moderate rainfall with isolated heavy to
very heavy rainfall and isolated extremely heavy rainfall very likely over districts of South Bengal
during next 24 hours. Also, due to strong monsoon flow, widespread light to moderate rainfall with
isolated heavy rainfall activity likely to continue in subsequent 6 days over some districts of South
Bengal. Detailed forecast and warning for next seven days are given below:
Realized rainfall in last 24 hours recorded at 0830 hours IST of 25.07.2025
Southwest Monsoon has been active over South Bengal.
Light to moderate rainfall occurred at most places over West Bengal with heavy to very rainfall at one
or two places over North 24 Parganas & Kolkata districts of South Bengal.
Chief Amount of Rainfall:
South Bengal(>=5 CM): MO Saltlake (North 24 Parganas) 13, Alipore (Kolkata) 8, Dum Dum (North 24
Parganas) 7, Sriniketan (Birbhum) 6.
North Bengal(>=1 CM): Singimari (Cooch Behar) 5.
Forecast and Warning for South Bengal:
25-07-2025:
Light to moderate rain/thundershower very likely to occur at most places over South Bengal with
Heavy to Very Rainfall (07-20 cm) at a few places associated with extremely heavy rainfall ( >20 cm)
at one or two places very likely to occur over Jhargram, Bankura and West Midnapore districts;
Heavy to Very Rainfall (07-20 cm) very likely to occur at one or two places over Howrah, East
Midnapore, Purulia, Hoogly, West Burdwan and South 24 Parganas districts; Heavy Rainfall (07-11
cm) very likely to occur at one or two places over rest districts of South Bengal.
Thunderstorm with Lightning and gusty wind (speed 40-50kmph) very likely to occur at one or two
places over all the districts of South Bengal.
26-07-2025:
Light to moderate rain/thundershower very likely to occur at most places over South Bengal with
Heavy Rainfall (07-11 cm) very likely to occur at one or two places over Purulia, Bankura, Sourh 24
Parganas districts of South Bengal.
Thunderstorm with Lightning and gusty wind (speed 30-40kmph) very likely to occur at one or two
places over all the districts of South Bengal.
27-07-2025:
Light to moderate rain/thundershower very likely to occur at many places over South Bengal with
Heavy Rainfall (07-11 cm) very likely to occur at one or two places over Nadia, Murshidabad districts of
South Bengal.
Thunderstorm with Lightning and gusty wind (speed 30-40kmph) very likely to occur at one or two
places over all the districts of South Bengal.
28-07-2025:
Light to moderate rain/thundershower very likely to occur at most places over South Bengal with
Heavy Rainfall (07-11 cm) very likely to occur at one or two places over Nadia, North 24 Parganas
districts of South Bengal.
29-07-2025.
Light to moderate rain/thundershower very likely to occur at most places over South Bengal with
Heavy to Very Rainfall (07-20 cm) very likely to occur at one or two places over North 24 Parganas
and South 24 Parganas districts; Heavy Rainfall (07-11 cm) very likely to occur at one or two places
over Kolkata, Howrah, Hoogly, East Burdwan, East and West Midnapore districts of South Bengal.
30-07-2025:
Light to moderate rain/thundershower very likely to occur at most places over South Bengal with
Heavy Rainfall (07-11 cm) very likely to occur at one or two places over East Burdwan, West Burdwan,
Birbhum, Purulia, Bankura districts of South Bengal.
31-07-2025:
Light to moderate rain/thundershower very likely to occur at many places over South Bengal with
Heavy Rainfall (07-11 cm) very likely to occur at one or two places over Birbhum, Murshidabad districts
of South Bengal.
Possible Impact for South Bengal
1. Water logging in low lying areas, underpass roads, temporary localized flooding/inundation
of low lying areas.
2. Reduction in visibility during intense spell of rain and Traffic disruption in urban areas.
3. Breaking of branches of trees, some damages to Kutchha Road, Kutchha houses, vulnerable
structure and wall collapsed of vulnerable Kutchha houses.
4. Rise in water levels of rivers.
5. Possibility of lightning strike especially in open field.
6. Some Damage to horticulture crops & vegetables in the field.
Actions suggested for South Bengal
1. Check for traffic congestion on your route before leaving for your destination.
2. Avoid movement water logging prone areas and staying in vulnerable structure.
3. Road traffic and ferry services in Hooghly River may be regulated judiciously.
4. Take shelter in safe place during intense spell of Rain/thundershowers activity.
5. Avoid taking shelter under tree/electric pole and avoid contact with water bodies.
Forecast and Warning for North Bengal:
25-07-2025:
Light to moderate rain/thundershower very likely to occur at most places over North Bengal with
Heavy Rainfall (07-11 cm) very likely to occur at one or two places over D a r j e e l i n g , Kalimpong
and Jalpaiguri districts of North Bengal.
Thunderstorm with Lightning and gusty wind (speed 30-40kmph) very likely to occur at one or two
places over all districts of North Bengal.
26-07-2025:
Light to moderate rain/thundershower very likely to occur at many places over North Bengal with
Heavy Rainfall (07-11 cm) very likely to occur at one or two places over Alipurduar and Jalpaiguri
districts of North Bengal.
27-07-2025:
Light to moderate rain/thundershower very likely to occur at most places over North Bengal with
Heavy Rainfall (07-11 cm) likely to occur at one or two places over Darjeeling, Jalpaiguri, Alipurduar
and Kalimpong districts of North Bengal.
28-07-2025 to 30-07-2025:
Light to moderate rain/thundershower very likely to occur at most places over North Bengal with
Heavy Rainfall (07-11 cm) likely to occur at one or two places over Darjeeling, Jalpaiguri, North and
South Dinajpur districts of North Bengal.
Possible Impact for North Bengal
1.Temporarily Water logging in low lying areas roads and reduction in visibility and possibility of
lightning strike especially in open field.
Actions suggested for North Bengal
1. Movement of traffic may be regulated judiciously.
2. Take shelter in a safe place during thunderstorm/intense spell of rain activity.
Warning for Fishermen of West Bengal:
Squally weather with surface wind speed reaching 35 to 45 kmph gusting to 55 kmph very likely to
prevail over North and Central Bay of Bengal and along and off West Bengal & Odisha coast from
25/07/2025 to 29/07/2025.
Fishermen are advised not to venture along and off North and central Bay of Bengal, and West
Bengal-Odisha coast from 25/07/2025 to 29/07/2025.
Port Warning:
Local cautionary signal – 3 hoisted at Kolkata & Haldia ports with sectional signal no-I hoisted at
Sagar Island port.
Warning maps are given at the end for graphical information.
N.B: Spatial rainfall distribution: Isolated: =< 25%, A few: 26-50%, Many: 51-75%, Most: 76-100%, Rainfall
amount (mm): Heavy rain: 64.5 – 115.5, Very heavy rain: 115.6 – 204.4, extremely heavy rain: 204.5 or
more.Probabilistic forecast: Unlikely =< 25%, likely 26-50%, Very likely 51-75%, Most likely > 75%
Color code for Warning:
Sd/-
(DR. H.R. Biswas)
Scientist -F
For Head, RMC, Kolkata
Next update will be given on 26.07.2025
Note: For detailed information please visit our
Website: https://mausam.imd.gov.in/kolkata/
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Flash Flood Guidance
24 hours Outlook for the Flash Flood Risk
(FFR) till 0530 IST of 26-07-2025 :
Low to Moderate flash flood risk likely over
few watersheds & neighbourhoods of East
Medinipur, Howrah, Jhargram, Pashchim
Medinipur, Puruliya, Bankura, and South 24
Parganas districts during next 24 hours
