India: Adverse weather forecast across northwestern regions through at least April 21

Adverse weather is forecast to continue across parts of northwestern India through at least April 21. The Indian Meteorological Department (IMD) has issued a special message warning of rainfall accompanied by thunderstorms, gusty winds, and lightning over northwestern regions April 18-21.

As of early April 17, the IMD has issued the following weather warnings across the affected area:

• Orange heavy rain, thunderstorm, strong wind, and lightning warnings (the middle level on a three-tier scale): Himachal Pradesh State and Jammu and Kashmir and Ladakh union territories April 18 and Himachal Pradesh and Uttarakhand states and Jammu and Kashmir and Ladakh union territories April 19

• Yellow heavy rain, thunderstorm, strong wind, and lightning warnings: Across most of the rest of the affected area April 18-21.

Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.

Sustained heavy rainfall could trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed stormwater drainage systems. Sites downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides are possible in hilly or mountainous areas, especially where heavy rain has saturated the soil.

Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days. Disruptions to electricity and telecommunications services are possible where significant flooding or landslides impact utility networks.

Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters. Severe weather could also trigger flight delays and cancellations at airports across the affected area.

Localized business disruptions may occur in low-lying areas; some businesses might not operate at full capacity because of flood damage to facilities, possible evacuations, and some employees' inability to reach work sites.

Flooding could heighten the threat of disease outbreaks. Backflow from drains mixed with floodwaters can become trapped in open areas when inundations recede. These stagnant pools often become a breeding ground for mosquitoes and bacteria, increasing the incidence of insect- and water-borne diseases. Exposure to contaminated water from inundated industrial sites, sewer systems, and septic tanks also poses a significant health threat.