South Asia: Some water surplus to persist in Bangladesh; deficits in Tamil Nadu, Uttarakhand

26 June 2017

The Big Picture
South Asia is forecast to experience moderate to severe deficit conditions across much of the region over the 12-month forecast period (below). Exceptional deficits are expected in central and southwestern Pakistan, in southern Chhattisgarh state and in eastern Tamil Nadu.

Surplus conditions are forecast to continue in Northern Pakistan, Punjab and Himachal Pradesh, and in Meghalaya extending into central Bangladesh.

Impacts
Flooding and landslides have displaced half a million people in Sri Lanka. In late May heavy rainfall triggered river overflows and mudslides that left over 150 people dead with the death toll rising, 112 missing, 1,800 homes damaged, and some towns under 18 feet of water. More than 2,000 military personnel were deployed to help Sri Lankan police and civilian agencies, and international relief efforts included food, medical teams, and inflatable boats from the United Nations, World Health Organization, World Food Programme, India, Pakistan, the US, China, Australia, and Russia. With rescue operations underway officials are also concerned about waterborne illnesses such as cholera and diarrhea, and have issued warnings about possible crocodile attacks.

In Assam, India, over 82,000 people have been affected by June flooding in four districts of the northeastern state, according to Assam State Disaster Management Authority, which left 146 villages under water, and 500 hectares of cropland damaged. Authorities have established 256 relief camps and distribution points.

In Mizoram State, just south of Assam, monsoon rains have brought the worst flooding in 50 years on the Tlawng River, killing at least 8 people, submerging 350 homes, and collapsing bridges and roads. And, in neighboring Tripura State flooding has left 2,000 homeless.

Forecast Breakdown
The 3-month composites (below) show the evolving conditions.

The forecast for June through August indicates a general moderating of extremes from recent observations with mild deficit conditions across most of India and Pakistan. Moderate to severe deficits may develop in Himachal Pradesh and Uttarakhand in the north of the country and Tamil Nadu in the south. Moderate to severe surpluses are forecast for Bangladesh, and surplus flow conditions are expected for the Indus River in Pakistan.

Conditions in the later forecast periods indicate mild deficits conditions should continue with some intensification in southwestern Pakistan in the September through November forecast, and intensification in western India toward the end of the forecast period with severe to exceptional deficit conditions developing in south and central Gujarat.

The forecast indicates limited areas of moderate to severe surpluses developing in Jammu & Kashmir September through February.

(It should be noted that forecast skill declines with longer lead times.)