Iran: Adverse weather forecast across much of the country through at least April 20

Adverse weather is forecast across much of Iran through at least April 20. Heavy rainfall, thunderstorms, strong winds, possible hail, and dust storms are forecast across much of central and southern Iran April 16-17. The most intense adverse weather is expected in parts of Bushehr, southern Fars, Hormozgan, southern Kerman, and southwestern and western Sistan va Baluchestan provinces April 16 and the southern half of Sistan va Baluchestan Province April 17. Scattered showers are expected in northern regions April 16 and strong winds may cause dust storms in eastern parts of Iran. Rough seas are expected along the Persian Gulf, Strait of Hormuz, and Sea of Oman coasts. Less intense rainfall is forecast to continue across southern regions April 18, as well as scattered showers in elevated northern regions. Further showers, storms, strong winds, and dust storms are expected in parts of southern Iran and elevated parts of northern and western Iran April 19-20.

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 additional mandatory evacuation orders for flood-prone communities. Disruptions to electricity and telecommunications services may occur where significant flooding or landslides impact utility networks.

Due to the arid nature of the region and poor stormwater management in some urban areas, even minor rainfall accumulations could quickly result in episodes of flash flooding. Flooding is possible in streams and dry riverbeds. Moderate winds and dust storms may precede significant rainfall, though some areas - particularly desert areas - may experience high dust levels without rain.

The severe weather will likely contribute to transport disruptions throughout the regions. Floodwaters and debris flows may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Additionally, 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. Traffic and commercial trucking delays might occur along regional highways. Flooding downpours could flood some low-lying roads in areas with poor drainage. Strong winds might also pose a hazard to high-profile vehicles.

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.