Southern Europe: Adverse weather forecast across Bosnia and Herzegovina, Croatia, Italy, Montenegro, and Slovenia through at least Aug. 6 /update 1

Event

Severe weather is forecast across parts of southern Europe through at least Aug. 6. A low-pressure system is expected to move southward over the Adriatic area Aug, 4-5, bringing heavy rainfall and thunderstorms to the region. The affected area includes much of Bosnia and Herzegovina, Croatia, Italy, Montenegro, and Slovenia. Strong wind gusts, lightning, and possible hail may accompany storms. Heavy downpours could trigger flooding in low-lying areas and landslides on unstable slopes. Strong winds may lead to power outages and property damage in affected areas.

As of Aug. 4, officials have issued the following weather warnings across the affected area:

• Red heavy rainfall warnings (the highest level on a three-tier scale): Central, northeastern, northwestern, and southeastern regions of Slovenia.

• Orange heavy rainfall warnings: Bihac and Prijedor regions in Bosnia and Herzegovina; Gospic, Karlovac, Rijeka, and Zagreb regions in Croatia; Umbria Region in Italy; and southwestern regions of Slovenia.

• Orange thunderstorm warnings: Rijeka and Split regions in Croatia; and Abruzzo, Friuli Venezia Giulia, Lombardy, Marche, Umbria, and Veneto regions in Italy.

• Orange strong wind warnings: Sardinia Region in Italy.

• Yellow heavy rainfall warnings: Banja Luka, Bihac, Livno, Mostar, Prijedor, and Tebinje regions in Bosnia and Herzegovina.

• Yellow thunderstorm warnings: Banja Luka, Livno, Mostar, and Tuzla regions in Bosnia and Herzegovina; Dubrovnik, Gospic, Karlovac, Osijek, and Zagreb regions in Croatia; Basilicata, Campania, Emilia-Romagna, Lazio, Liguria, Piedmont, Puglia, Sicily, Tuscany, Trentino Alto Adige, and Valle d'Aosta regions in Italy; and northwestern, southeastern, and southwestern regions of Slovenia.

• Yellow strong wind warnings: All coastal waters of Croatia; and Calabria, Lombardy, Piedmont, Sicily, Trentino Alto Adige, and Valle d'Aosta regions in Italy.

Montenegro's Institute for Hydrometeorology and Seismology (ZHMS) has issued orange heavy rainfall and thunderstorm warnings across the country Aug. 5. Officials will likely update and extend the coverage of weather alerts over the coming days.

Hazardous Conditions
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 rainfall 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.

Transport
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. The disruptive weather may cause some delays and cancelations at airports in the affected regions. Flooding could block regional rail lines; freight cancellations are possible in areas with heavy rainfall and potential track blockages.

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

Advice

Monitor local media for weather updates and related advisories. Confirm all transport reservations and business appointments before travel. Make allowances for localized travel delays and potential supply chain disruptions where flooding is forecast. Do not drive on flooded roads. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

MeteoAlarm
Bosnia and Herzegovina Federal Hydrometeorological Insitute
Croatia Meteorological and Hydrological Service (DHMZ)
Servizio Meteorologico Aeronautica Militare
Montenegro Institute for Hydrometeorology and Seismology (ZHMS)
Slovenia Environment Agency