No. W – 00102 / IX / Date: 28.06.
2025
Time: 1300 Hrs IST
Special Bulletin : 4
Subject: : Likely formation of a Low Pressure System over north Bay of Bengal and
adjoining coastal Bangladesh & West Bengal during next 48 hours.
An upper air cyclonic circulation lies over southwest Bangladesh & adjoining Gangetic West
Bengal extends upto 7.6 km above mean sea level tilting southwestwards with height.
Under its influence a low-pressure area is likely to form over the north Bay of Bengal and
adjoining coastal Bangladesh and West Bengal during next 48 hours. Subsequently it is likely to
move slowly west-northwestwards across Gangetic West Bengal and north Odisha & Jharkhand.
The east-west trough ran from the upper air cyclonic circulation over southwest Bangladesh
& adjoining Gangetic West Bengal to northeast Madhya Pradesh across Jharkhand, north
Chhattisgarh between 3.1 & 4.5 km above mean sea level.
Under their influence, light to moderate rainfall at most places with isolated heavy to very
heavy rainfall very likely in some districts of West Bengal.
The detailed forecast and warning for next 7days as follows:
Forecast and Warning for South Bengal:
28-06-2025:
Light to moderate rain/thundershower very likely to occur at most places over all the districts of South
Bengal with Heavy Rainfall (7-11 cm) very likely to occur at one or two places over East Midnapore,
West Midnapore, South 24 Parganas, North 24 Parganas, Howrah, Hooghly, Purulia and Jhargram
districts of South Bengal. Thunderstorm with gusty wind (speed reaching 30-40 kmph) and lightning
likely to occur at one or two places over all the districts of South Bengal.
29-06-2025:
Light to moderate rain/thundershower very likely to occur at most places over all the districts of South
Bengal with Heavy to very Heavy rainfall (07-20 cm) very likely to occur at one or two places over
South 24 Parganas, East Midnapore, West Midnapore, Bankura and Jhargram districts and Heavy
Rainfall (7-11 cm) very likely to occur at one or two places over East Burdwan, West Burdwan, North
24 Parganas, Hooghly, Howrah, Kolkata, Purulia and North 24 Parganas districts of South Bengal.
Thunderstorm with gusty wind (speed reaching 30-40 kmph) and lightning likely to occur at one or
two places over all the districts of South Bengal.
30-06-2025:
Light to moderate rain/thundershower very likely to occur at most places over all the districts of South
Bengal with Heavy to very Heavy rainfall (07-20 cm) very likely to occur at one or two places over East
Midnapore, West Midnapore, Jhargram, Bankura and Purulia districts of South Bengal and Heavy
Rainfall (7-11 cm) very likely to occur at one or two places over Birbhum, East Burdwan, West
Burdwan, Hooghly, Howrah and South 24 Parganas districts of South Bengal. Thunderstorm with gusty
wind (speed reaching 30-40 kmph) and lightning likely to occur at one or two places over all the
districts of South Bengal.
01-07-2025:
Light to moderate rain/thundershower very likely to occur at most places over all the districts of South
Bengal with Heavy Rainfall (7-11 cm) very likely to occur at one or two places over Murshidabad,
Birbhum, Purulia and West Burdwan districts of South Bengal.
02-07-2025 & 03-07-2025:
Light to moderate rain/thundershower very likely to occur at many places over all the districts of South
Bengal.
04-07-2025:
Light to moderate rain/thundershower very likely to occur at most places over all the districts of South
Bengal with Heavy Rainfall (7-11 cm) very likely to occur at one or two places over North 24 Parganas
and South 24 Parganas districts of South Bengal.
Possible Impact for South Bengal:
1. Temporarily Water logging in low lying areas and reduction in visibility during intense spell of rain.
Traffic disruption in urban areas.
2. Possibility of lightning strike especially in open field.
3. Some Damage to horticulture crops & vegetables in the field.
Actions suggested for South Bengal:
1. Movement of traffic may be regulated judiciously.
2. Take shelter in safe place during thunderstorm with lightning activity and avoid taking shelter
under tree/electric pole & avoid contact with water bodies.
3. Do not use fertilizer & pesticides as it may wash out.
Forecast and Warning for North Bengal:
28-06-2025:
Light to moderate rain/thundershower very likely to occur at many places over all the districts of North
Bengal with Thunderstorm with lightning likely to occur at one or two places over all the districts of
North Bengal.
29-06-2025:
Light to moderate rain/thundershower very likely to occur at many places over all the districts of North
Bengal.
30-06-2025:
Light to moderate rain/thundershower very likely to occur at most places over all the districts of North
Bengal with Heavy Rainfall (7-11 cm) very likely to occur at one or two places over Darjeeling,
Jalpaiguri, Coochbehar and Alipurduar districts of North Bengal.
01-07-2025:
Light to moderate rain/thundershower very likely to occur at most places over all the districts of North
Bengal with Heavy Rainfall (7-11 cm) very likely to occur at one or two places over Darjeeling,
Jalpaiguri and Alipurduar districts of North Bengal.
02-07-2025:
Light to moderate rain/thundershower very likely to occur at most places over Darjeeling, Kalimpong,
Jalpaiguri, Coochbehar and Alipurduar districts and at many places over the rest districts of North
Bengal with Heavy Rainfall (7-11 cm) very likely to occur at one or two places over Darjeeling,
Kalimpong, Jalpaiguri, Coochbehar and Alipurduar districts of North Bengal.
03-07-2025 & 04-07-2025:
Light to moderate rain/thundershower very likely to occur at most places over Darjeeling, Kalimpong,
Jalpaiguri, Coochbehar and Alipurduar districts and at many places over the rest districts of North
Bengal.
Possible Impact for North Bengal:
1. Possibility of lightning strike especially in open field.
Actions suggested for North Bengal:
1. Take shelter in safe place during thunderstorm with lightning activity and avoid taking shelter
under tree/electric pole & avoid contact with water bodies.
Warning for Fishermen of West Bengal:
Squally weather with surface wind speed reaching 35–45 kmph gusting to 55 kmph is very likely over
Odisha– West Bengal coast, North Bay of Bengal adjoining West-central Bay of Bengal till 1st July, 2025.
Sea condition is very likely to be rough.
Fishermen are advised not to venture into the north Bay, adjoining west central Bay of Bengal and
along and off West Bengal-Odisha coast till 01st July 2025.
Next update will be given on 29.06.2025.
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. Anwesa Bhattacharya)
Scientist -C
For Head, RMC, Kolkata
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