Iran, Iraq: Adverse weather forecast to continue across the region through at least May 7 /update 1

Severe weather is forecast to continue across much of Iran and Iraq through at least May 7. Heavy rainfall and thunderstorms have been ongoing across the region in recent days and will continue over isolated parts of both countries May 4-5 before a new weather system brings further widespread showers and storms from May 6. Storms may be accompanied by strong wind gusts, lightning, and possible hail. Heavy downpours may trigger flooding in low-lying areas and landslides on unstable slopes. Strong winds may cause property damage and power outages.

Iranian meteorological authorities have forecast showers and storms will continue over eastern, northern, and western regions May 3, with light rainfall possible over much of the rest of the country. Further scattered showers and storms are expected primarily across northern regions May 4-5 before rainfall moves in across the western half of the country May 6.

The Iraqi Meteorological and Seismology Organization has forecast cloudy conditions across Iraq over the coming days, with showers and thunderstorms likely to persist across northern regions May 3-6. More widespread thunderstorms are expected across the country May 7, with the most intense storms likely in eastern and northern regions.

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 or a lack of 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 the soil has become saturated by heavy rainfall.

Authorities may issue mandatory evacuation orders for flood-prone communities over the coming days. Disruptions to electricity and telecommunications services are possible where significant winds, flooding, and/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 wadis (dry riverbeds). Significant rainfall may be preceded by moderate winds and dust storms, though some areas - particularly desert areas - may experience high levels of dust without rain.

The severe weather could contribute to transport disruptions throughout the affected area. Floodwaters and debris flows could render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Traffic and commercial trucking delays might occur along regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters. Strong winds may also pose a hazard to high-profile vehicles.

Hazardous weather conditions may cause flight delays and cancellations at airports in the region. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and potential track inundation.

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.