Cyclonic storm 'Montha' over the west-central Bay of Bengal moved north to northwestwards with a speed of 15 kmph during the past six hours and intensified into a severe cyclonic storm by 5.30 am on Tuesday, said the India Meteorological Department (IMD).

The weather system lay centred 190 km south to southeast of Machilipatnam, 270 km south to southeast of Kakinada and 340 km south to southeast of Vizag at 5.30 am.