BB1 lies as a deep depression at 22.4N and 88.5E, 50 kms NW of Kolkata. On crossing over Kolkata, the city had 107 mms of rain at Alipore and 117 mms of rain at the airport, in 9hrs on Friday. Currently on the mentioned location, the pressure is at 990 mb.
As mentioned yesterday, there are 2 possibilities for the system to track.
-1. BB1could track North/North-West, thru Northern parts of Bengal and into the Northern trough. By Saturday evening, it would weaken a bit, and move into Central and Eastern parts of Nepal. Fizzle out by Monday over the Nepal Himalayas. Result: Heavy rains on Sat in Bengal, Bihar, Jharkhand and Central/Eastern Nepal. Also good rainfall in Eastern U.P.
In this case, rainfall along the west coast would weaken from Monday, and a "break monsoon" situation" of reduced rainfall in Mah, Gujarat, Karnataka and west M.P. would prevail.
-2. BB1 would track West/NW, and move along into Chattisgarh by Saturday/ Sunday. Later moving west, it would track into M.P. and fizzle out there by Mon/Tues.
Here, heavy rain in Bengal and Bihar and Jharkhand on Sat, and then in M.P. and Vidharbha on Sun. On Sunday, rainfall could increase along the west coast as the system moves westinto M.P. System would fizzle out by Tuesday over west M.P.
Vagaries would go in for scenario No. 1.The first option seems more probable.
Saturday/Sunday: Uncomfortable humid heat. Sunny intervals with some showers, but not prolonged. Passing showers will be sharp. Rain amounts about 25 mms per day.