An anticipated low-pressure area formed over the South Andaman Sea and adjoining South-East Bay of Bengal on Friday, two days later than initially forecast and with prospects for intensification over extended phases.
The India Met Department (IMD) itself said that the intensification will be slower and may get delayed. The low may become well-marked during the next two days, and concentrate into a depression over the Andaman Sea and the adjoining South-East Bay around May 5 and intensify further thereafter.
No stress on Myanmar track
The track is likely to be the North-North-West till May 5 (oriented towards the East Coast). Significantly, the IMD doesn’t maintain the outlook for a change in track towards Myanmar-Bangladesh. Experts are of the view that the delay in intensification and the longer stay in the warm waters could affect storm dynamics and change its behaviour.
A likely track into a warmer West-Central Bay (sea surface temperatures closer to 30 degrees Celsius or above), as a few models venture to suggest, could intensify it to near-cyclone strength. The South-East and adjoining South Andaman Sea, where it is currently are cooler at 28-29 degrees Celsius.
Adverse weather forecast
A few models project that the storm (a likely deep depression, as indicated by the US Navy Global Environmental model) may inch closer to the Andhra Pradesh coast before veering to the opposite (North-North-East) and run into cooler North and North-East Bay of Bengal. The European Centre for Medium-Range Weather Forecast suspects the storm intensify and may reach closer to Visakhapatnam by May 10 till when its outlook is available.
On Friday, squally winds with speeds reaching 40-50 km/hr gusting to 60 km/hr may prevail over South-East Bay of Bengal. The sea condition will be rough to very rough (wave heights of 8-20 ft) over North Sumatra coast, South Andaman Sea and adjoining South-East Bay. Fishermen are advised caution.
As for Saturday, squally winds (40-50 km/hr) gusting to 65 km/hr may prevail over the South-East Bay and South Andaman Sea. The sea condition will remain rough to very rough over the South-East Bay and the South Andaman Sea. Fishermen are advised not to venture into these areas.
Two deadlines pass
Earlier, two timelines for the first pre-monsoon low-pressure area to form in the Bay had passed, forcing the IMD to extend watch for another 12 hours (into Friday evening). April 29 was as the initial timeline, pushed later by a day. Normally, this is taken to mean the likely loss of confidence with respect to the forecast time and place of its eventual occurrence.
One potential reason why the storm dynamics are getting affected is the competing pull on the south-westerly flows it shares with a stronger circulation over the East Indian Ocean off Sumatra (Indonesia) and a less-intense ones over the Malacca Strait (off Malaysia), from where it had reached the South Andaman Sea. The Sumatran circulation could have to blink first for the low-pressure area over South Andaman Sea to prosper and intensify.