Updated 02:30 PM on Dec 11: The low-pressure area has weakened further and now prevails as a cyclonic circulation over Bangladesh and adjoining Assam.
Updated 10:30 AM on Dec 11: Low-Pressure Area weakens more
The low-pressure area over northeast Bay of Bengal and adjoining areas has become less marked. An associated cyclonic circulation is extending up to 3.1 km above sea level.
Updated 11:30 AM on Dec 10: Depression fades into low pressure, to weaken further
Yesterday, the depression which was over Northwest Bay of Bengal has moved steadily north-northeastwards and weakened into a well-marked low pressure. Further, the same system debilitated into a low pressure area. Now the system is marked over North Bay of Bengal.
This weather system is most anticipated to continue its track in north-northeast direction and slowly dwindle. In wake of this, light rains are possible over southern districts of Gangetic West Bengal such as Digha, Bankura, Bardhaman, Birbhum and Haldia amid the next three to four hours. While light to moderate rains are expected over the northeastern states of Tripura, Mizoram, Manipur and South Assam.
Now, the weather conditions will recover over the state of Odisha as the system has moved away from the region, thus day maximums will mark an upward inclination and night temperatures, on the other hand will fall.
The weather over Gangetic West Bengal will slowly improve as the same system will be weakening further and moving away.
Updated on December 9, 2017, 05:00 PM: Depression nears east coast, rain in Kolkata, West Bengal, Northeast
The deep depression in Bay has become a dialog of mystery on account of its intensity and track. As according to IMD (India Meteorological Department, the system in Bay has weakened into a depression and centered near Latitude 19.5°N and Longitude 86.7°E, about 90 km south of Paradip and 280 km south-southwest of Digha.
Contrary to this, JTWC (Joint Typhoon Warning Center), the same system has strengthened into a Tropical Cyclone 04B and centered near Latitude 19.3°N and Longitude 86.9°E.
Now, looking at the dense overcast circular cloud mass of the system and its feeder clouds, we could say that the system is most likely to intensify into a weak cyclonic storm.
Yesterday, as per Skymet Met Dept. the system was anticipated to weaken on account of the unfavorable sea parameters such as wind shear and sea surface temperatures and the system was expected to possibly fight against these odds to intensify into a cyclone.
However the configuration shows that the system is not likely to retain its strength for a long duration due to the proximity of the coast. On the other extreme, within 24 hours, surely it will weaken. The system will move further northwards and later northeastwards.
This system is potent enough to give heavy rains over the coastal districts of West Bengal that would be accompanied with squally winds. Kolkata could also witness varying intensity of rains during the two days. Sea conditions will be rough, so fishermen are advised to avoid venturing out in the sea. However, with northeast movement of the system rains will reduce over the Kolkata.
Meanwhile, Tripura, and Mizoram will see fairly widespread rains with some heavy falls, moderate showers are anticipated over Assam, Meghalaya, Nagaland and Manipur. Scattered rains are also possible over Arunachal Pradesh.
Updated on December 8, 2017, 11:00 AM: Deep depression forms in Bay, uncertainty over cyclone formation
The Depression over southeast and adjoining central Bay of Bengal has intensified further into a deep depression during the wee hours of December 8. It has moved further in northnorthwest direction and is now seen over Central Bay of Bengal.
It is centered at Latitude 14.3°N and Longitude 87°E, around 590 km southsoutheast of Gopalpur and 660 km eastsoutheast of Machilipatnam.
According to Skymet Weather, the system is presently travelling in the favourable weather conditions and it is likely to maintain the intensity of deep depression for some time.
It may or may not intensify further but we have to wait and watch for the phenomenon to occur. However, as the system would continue to move northnorthwestwards, it would enter into comparatively cooler sea surface temperatures that would hamper its further strengthening.
Weather models are indicating that system is most likely to cross the East Coast of India somewhere between North Andhra Pradesh and South Odisha by December 9.
In wake of this system, light rains have already commenced over the coastal areas of Andhra Pradesh, Odisha and Gangetic West Bengal. As the system nears the coast, intensity of rains would increase over all these areas.
Updated on December 7, 2017, 06:30 PM:
Updated on December 7, 2017, 03:00 PM:
The depression persisting over the southeast Bay of Bengal has moved northwards in the past six hours. Presently the speed of squally winds is 50 to 55 kmph. The cloud formation is showing signs of intensification and hence this system is likely to concentrate into a deep depression in the next 12 hours.
It will move northwards inching close to the coast. Wind shear and sea surface temperatures will continue to favour its growth. In wake of this weather system, light rainfall is likely to commence over North Coastal Andhra Pradesh, Odisha and Gangetic West Bengal from the night of December 7.
Thereafter, rainfall activity is likely to pick up the pace gradually. The sea conditions will remain rough during that time and hence fishermen and locals are advised to take precautions before venturing out into the sea.
Updated on December 6, 2017, 01:00 PM: Well marked low-pressure area over southeast Bay of Bengal and adjoining areas has intensified into a depression and at 08.30 hours it was over Lat 8.5 N and long 88.5 E about 1160 km southeast of Machilipatnam and 1250 km south-southeast of Gopalpur.
It will move in a northwest direction and further intensify into a deep depression. It will reach over the coast of North Andhra Pradesh and adjoining South Odisha by the night of December 8 or morning of December 9. Light rain will commence over coastal Andhra Pradesh and Odisha from tomorrow and will intensify on December 9. Gangetic West Bengal may also start receiving rains by the.
Update on December 6, 2017, 11:00 AM:
Now the well-marked low over the southeast Arabian Sea is likely to intensify into a depression by today afternoon and may further intensify into a deep depression by tomorrow. Initially, it will move in a northwest direction. After reaching west-central Bay of Bengal it will start recurving in north-northwest direction towards south Odisha coast.
Therefore, we expect scattered rains over North coastal Andhra Pradesh on December 7 and 8. Coastal Odisha may receive moderate to heavy rains between December 8 and 9. During the course of its journey, it will start effecting Gangetic West Bengal, Nagaland, Manipur, Mizoram, and Tripura in terms of light to moderate rains.
We expect rains to commence over these states by December 9 or 10 and will continue until December 10. However heavy to very heavy rains may not occur. Tamil Nadu will be spared by the weather system.
Update on December 5, 2017, 7:00 PM:
The well-marked low-pressure area over the southeast Bay of Bengal and adjoining south Andaman Sea continues to sustain its strength. In wake of this, heavy rains to extremely heavy rains have lashed southern parts of Andaman and Nicobar Islands.
Nancowry recorded 191 mm of rains in the span of 24 hours from 8:30 am on Monday, followed by Car Nicobar with 147 mm.
According to Skymet Weather, the system remained practically stationary during the last 24 hours, getting more marked. The system would most likely continue to move in west-northwest direction.
Cloud configuration and atmospheric conditions are indicating towards intensification of the system into a depression by December 6 and further concentrating into a deep depression in subsequent 24-48 hours.
By December 7, the system is likely to re-curve in north-northwest direction towards Andhra Pradesh coast. Thus, with the weather system moving towards west-central Bay of Bengal, it will enter into cooler sea surface temperatures. Therefore, chances of intensification into a cyclonic remain bleak.
Rain along the East Coast of India
As the weather systems tracks further in Bay of Bengal, it will escape Tamil Nadu including Chennai. We expect mainly light rains with isolated moderate showers over Chennai on December 7. However, weather system would not have any impact in terms of heavy rains.
Meanwhile, coastal Andhra Pradesh and Odisha may receive moderate to heavy rain on December 7 and 8. With the system further tracking north, Gangetic West Bengal and Northeast India would also see light to moderate rains including Kolkata on December 8 and 9.
Any information taken from here should be credited to skymetweather.com