Austria, Hungary: Heavy rain and thunderstorms forecast across Hungary and eastern and southern Austria through at least May 17

Heavy rain and thunderstorms are forecast to occur across Hungary and much of eastern and southern Austria through at least May 17. 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.

The Meteorological Service of Hungary has issued yellow (the lowest level on a three-tier scale) heavy rainfall warnings across western regions and yellow thunderstorm warnings across southern and western regions May 16. Orange thunderstorm warnings are in place for Bacs-Kiskun, Fejer, and Pest counties and yellow thunderstorm warnings across the rest of the country May 17. Yellow heavy rainfall warnings are also in place across Hungary May 17.

The Austria Central Institution for Meteorology and Geodynamics (ZAMG) has issued orange heavy rainfall warnings across parts of eastern, east-central, and southeastern Carinthia State and yellow rainfall warnings across southern Austria May 16-17. Yellow heavy rainfall warnings are in place across eastern Austria and yellow thunderstorm warnings for eastern and east-central regions May 17.

Officials could update and possibly extend the coverage of the weather alerts over the coming hours and 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 or a lack of stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall. Landslides cannot be discounted in hilly or mountainous areas, especially where the soil has become saturated by heavy rainfall.

Authorities could issue mandatory evacuation orders for flood-prone communities over the coming days. The adverse weather conditions could cause power outages throughout the affected area.

The severe weather will likely contribute to transport disruptions throughout the region. Traffic and commercial trucking delays might occur along regional highways. Strong winds might pose a hazard to high-profile vehicles. 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 in the region. Flooding could block regional rail lines; freight and passenger train delays and cancellations are likely in areas that see heavy rainfall and potential track inundation.

Disruptions triggered by inclement weather and resultant hazards, such as flooding, could persist well after conditions have improved - it could take days before any floodwaters recede and/or officials clear debris. If there is severe damage to infrastructure, repair or reconstruction efforts may result in residual disruptions.