As monsoon clouds remained tantalisingly still at the border of Maharashtra and Karnataka, anxious officials in Maharashtra on Friday began to discuss the option of cloud seeding to help agriculture in a state that has been affected by four consecutive years of drought. Now that the rain has covered the Konkan, central Maharashtra and Vidarbha, these plans might be shelved.

Central Maharashtra has been mostly dry until now, apart from a few pre-monsoon showers. The exception so far has been Latur, which made national headlines for its water crisis in May, and which got 121.9% of its normal rainfall for that period between June 1 and 12. Other parts of Marathwada including Beed and Osmanabad also got three days of heavy rain before dry weather resumed.

Government officials both from the state and from the India Meteorological Department have been putting out newspaper advertisements and conducting field visits to urge farmers against sowing seeds until the monsoon actually arrives, for fear of them losing their investment in the dry period that has followed since.

The monsoon ordinarily covers most of Gujarat, Madhya Pradesh and Bihar by June 15. This year, as of June 20, the monsoon has only covered Chhattisgarh, Odisha, West Bengal, the North East and the southern and eastern extremities of Maharashtra and Jharkhand.

As this map from the India Meteorological Department shows, the usual progression over India has inverted, with eastern parts of the country getting rain mostly on time, while the northern and western parts remain dry well past the usual onset dates.

This is because of how the monsoon spreads across India. As clouds gather over the Indian Ocean and begin to move northward, two branches of the south west monsoon begin to form, one over the Arabian Sea and the other over the Bay of Bengal. Neither are active at the same time, explained Charan Singh, a scientist at the India Meteorological Department. When one strengthens, the other weakens and the monsoon progresses in pulses lasting from five to seven days across the two branches.

The branch active at present is the eastern one, that covers eastern and North Eastern India. The monsoon covered the north east on June 14, ten days after its normal onset on June 5, said a duty officer at the department’s regional meteorological centre in Guwahati. While this might seem late, it is on time in the region relative to the onset of the monsoon in Kerala on June 8, a day later than forecast.

This is also why Odisha and Chhatisgarh saw heavy rain on Sunday, while neighbouring Vidarbha in eastern Maharashtra had light showers.

The Arabian Sea branch, on the other hand, has halted at the border of Karnataka and Maharashtra. It is expected to move northwards and cover Marathwada and western Maharashtra over the next few days. Most parts of India, except the northwest, including Gujarat, Rajasthan, Punjab and Jammu and Kashmir, are expected to get rain by June 23, the department said in its latest forecast.

The monsoon had stalled for five consecutive days at this time of the year in 2015 as well, but with eastern parts of India facing delays instead.

As the Indian Express reminded readers, the late onset of rains does not necessarily mean less rainfall.

And even after the monsoon has spread across India, as it is expected to by July, the entire country will not receive continuous rain, Singh explained, but alternate between wet and dry patches depending on the formation of troughs, or pockets of low pressure, in different parts.