Current Weather Conditions on 30th October 2012 @ 7.30 am.
Deep Depression over the Bay of Bengal was 40 Kms. East off the Srilanka Coast located at 8.5N & 81.7E. as per JTWC at 0000UTC ( 05.30 am.IST) who put this System at 40 knots winds (75 Kms/hour 1 min. ave. speed ) and 993 Mb. pressure.
IMD issued Bulletin BOB 02/2012/08 Dated: 30.10.2012, Time of issue: 0330 hours IST, Sub: Deep Depression over southwest Bay of Bengal: Cyclone Alert for North Tamil Nadu, Puducherry and adjoining South Andhra Pradesh coasts.
As per this IMD Bulletin the Deep Depression was located at 9.0N & 82E. on 29th October 1800UTC (11.30 pm IST) with 55 to 65 Kms. winds and gusting to 75 Km.
As per JTWC this System has 40 knots winds ( 1 Minute average speed)
IMD uses the 3 minutes average wind speed and if it reaches 35 knots Cyclonic Storm “NILAM” would be declared by RSMC/IMD New Delhi.
NRL Satellite Image of 02B.TWO – Deep Depression on 30th October 2012 @ 6.30 am. IST
The Forecast track from different Models is vastly different. Judging by the current position GFS 1800Z forecast track takes this system for landfall over Tamilnadu Coast just South of Cuddalore on 31st. ECMWF model has this System tracking parallel to the Tamilnadu Coast and bypassing Chennai and subsequently making landfall near Nellore. IMD Forecast track says around Pudducherry.