A vigorous phase of monsoon to return after a prolong break

 

After a long period of dry and hot weather, Indo Gangetic Plains are set to witness a final round of active monsoon conditions. 

Many places across the plains saw an awful monsoon in August but Pan India performance was above normal.

Relief from prolong hot and humid spell is slowing setting in. Considering the parameters, 2nd half of the September look really good in terms of rains. Also a delayed monsoon withdrawal is expected 

Synopsis 

• Low pressure to form in the Bay of Bengal and intensify into a Depression and get embedded in the through (Shearzone)

• ShearZone to form over South and adjoining Central India and move Northward 

• Moderate to strong Westerlies surge 

• Vortex near Mumbai-North Konkan

•WD over Northern Himalayas ( likely to pull the shearzone and the embedded depression straight north, likely over Haryana-Delhi-W UttarPradesh region) 🔺No WD for next 5 days 🔺

Weather forecast and events

• Westerly surge due to pull effect of the Low/Depression and vortex over North Konkan is expected to produce moderate to heavy rain associated with mild-strong thunderstorms and winds upto 20-50km/h (Gusts upto 40-70km/h) in Mumbai, Raigad, Valsad, Thane, Vaisai, Virar and parts of interior Maharashtra and parts of Konkan b/w 9-15 September 

-Strong tstorms and moderate rains with few heavy spells in mumbai and the surrounding areas b/w 11-14 Sep then slight increase in the intensity on 12-13 Sep.

-As the system moves Northward these activities to moves up into the parts of Valsad-Surat-Gujarat-Rajasthan (Watchout for severe rains for Gujarat and S Rajasthan and adj places b/w 13-15 September 

-Localised patchy action is also expected across many places between 10th till 18th September 

-Each spell to pour 10-50mm whereas strong ones could pour 50-140mm

⚠️ Lightning strike, waterlogging and low level flooding at places

🔺Mumbai to get thunderless rains for 70% of the time

•East India to get similar action with scattered moderate to heavy rains associated with strong thunderstorms, winds gusting upto 40-80km/h and patchy rains due to Depression and the shear zone  moving close south of states. High risk for Odisha, Kolkata, West Bengal, East MadhyaPradesh, East UttarPradesh, And prts of Bihar and adjoining areas. 11-13 Southern and eastern most places and 13-15 places above them)

- Patchy localised rains to occur for next remaining half of the September and 80-95% of the areas to be covered 

-Each spell cloud dump 5-40mm of rain whereas strong ones cloud dump 50-130mm

⚠️ Flash Flooding, Heavy Rains, Lightning strikes, Strong winds

•Central India to get Moderate to heavy and varied intensity spells along with winds and thunder as the Shear zone and the Low/Depression to move over MadhyaPradesh and adj Uttarpradesh and Maharashtra. Various parts to get varied intensity rains likely between late 13-16 Sep

-Localised spells cannot be ruled out

⚠️ Flash Flooding at places, Crop damage, Waterlogging, Heavy Rains, Lightning strikes, Strong winds

Finally our favourite 

North and NorthWest India: Winds are already replaced by moist easterlies which is helping in highly localised rains & tstorms. Movement of Shear zone and embedded Depression to favour good rains. The system is expected to move northwards due pull effect of a western disturbance over northern Himalayas (Jet Stream starts to dip south as the tilt of the earth shifts and it moves further north during the summer and lower south during winters thus creating favourable conditions for connecting other weather systems moving W-NW)

-Nature of the spells to remain highly localised and patchy until the system moves close to Gwalior (till  14th Sep)

-Intensity and the spread of the patchy spells to increase from 12th Sep

-Red Alert will be given for 4-5 days i.e 14-18th Sep. 

-Highly localised activities are expected in pockets of Delhi, Uttarpradesh, Haryana, Punjab, North Rajasthan and adj areas till 20th

-Good moderate to heavy rains along with some thunder and winds upto 20-40km/h is expected over Delhi, S-N-E Haryana, W UttarPradesh amd parts of Punjab and adj Rajasthan from 12th till 14th Sep

-Gradually increase in intensity and spread is expected from late 14th Sep with winds strengthening upto 35-65km/h 

-Peak of the spell shall start on 15 and lasting for 3 days. Activities to subside from 18th onwards

-As of now core zone for heavy rains/ts and flash floods in some pockets lies over Delhi-West UttarPradesh, N Haryana (More precise forecast will be shared on Fb and Twt)

-Estimated Rainfall is 40 to 350mm. Lower for some areas as individuals spells to cover 75-95% of the areas 

🔺Floods and very heavy rainfall warning for Dharamshala, Mandi, Shimla, parts of Jammu and Kashmir, HimachalPradesh, Uttarakhand, Dehradun and adjoining hilly areas. As clouds forms and remains stagnant and they have the potential to dump huge amounts of rains in short duration of time. It is advised to avoid travelling to these areas until 20th Sep

⚠️Moderate-Heavy rains to cause waterlogging, traffic disturbances, flooding in fields, Lightning strikes, gusty winds could cause power distributions, Crop damage as crops are ripening and some are in need for rains as the temps were as high as 36-39°C 

🔹Stay alert between 14-19th Sep 

•Overall 2nd Half of the September to fill all the deficits caused by missing rains.

🔸Monsoon withdrawal to start from late September, high chances for early October