Southwest monsoon has been playing errant during this month. It behaved rather well in July leaving a monthly surplus of 13%, neutralizing effectively the June shortfall. However, this seasonal feature has gone into limbo, right at the beginning of August and continues behaving truant for most parts of the country. There are bleak chances of recovery, leaving anxious moments for most of the rainfed areas, including the core monsoon zone of central and western parts.
The month of August is a preferred time for a ‘break’ in the monsoon. Having a break after an active phase, like what happened in July, is quite normal. But a prolonged break, as was witnessed early in August, extending for nearly 2 weeks, from 4th to 17th August does not augur well. This weak phase consumed the seasonal surplus of 5% and plunged to a deficit of 6% (LPA) by 17 August 2023. Following a monsoon low pressure, albeit a mild one, between the 18th and 20th August, decent rains were observed over the eastern states and central regions covering Chhattisgarh and Madhya Pradesh. Even, conciliatory moderate to heavy rainfall was observed over Vidarbha, Telangana and parts of East Rajasthan and Uttar Pradesh.
Remnant of this low-pressure area shifted to parts of North Madhya Pradesh and Southwest Uttar Pradesh. There have been moderate to heavy showers in the past 24 hours over Uttar Pradesh and North Madhya Pradesh. This weather system is now reduced to a cyclonic circulation, embedded in the monsoon trough, which is extending from Punjab to West Bengal and further on to Assam and Arunachal Pradesh. This cyclonic circulation and monsoon trough, working in tandem, have accentuated the monsoon activity over Uttar Pradesh, Madhya Pradesh, Bihar and West Bengal. Active monsoon conditions are expected over these parts and especially along the foothills of the Himalayas in the next 48 hours. However, the monsoon trough will shift further north of its normal position, all along the foothills of Uttarakhand, Uttar Pradesh, Bihar, Sikkim, Sub Himalayan West Bengal and Assam valley.
Monsoon will go into a ‘break’ once again from 25th August onward. This break might as well extend into the first week of September. Rainfall activity will get limited to the foothills of Uttar Pradesh, Bihar, Sikkim, North Bengal, Arunachal Pradesh and Assam & Meghalaya. There will be an uptick in weather activity over other northeastern states as well.
Weak monsoon and break monsoon period favours moderate showers over Coastal Andhra Pradesh and Tamil Nadu. An offshore north-south trough over these parts triggers decent showers till the weak phase lasts. The seasonal rainfall deficit stands at 7% of the long period average (LPA). While the rainfall activity will be intense in some parts including states of Himachal Pradesh, Uttrakhand, Uttar Pradesh, Bihar, Sikkim, Sub Himalayan West Bengal and northeastern parts, most other regions will observe subdued monsoon activity. Seasonal rainfall deficit may get restricted to the existing 7% of LPA for the next 2 days. Thereafter, scanty rains over western, central and northern parts of the country will raise the deficit to possibly double digits by the end of the month or opening days of September.
