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

Adverse weather is forecast across much of Greece through at least April 20. The Hellenic National Meteorological Service has issued an updated orange level Emergency Deterioration of Weather Bulletin (the middle level on a three-tier scale), warning that a low-pressure system will bring unstable weather across much of the country from early afternoon April 19 through noon April 20. Heavy rainfall accompanied by thunderstorms and strong winds is initially forecast to impact western regions before spreading across much of the country through late April 19 and persisting in northern and eastern regions through early April 20. Snowfall is possible in elevated areas of western and northern Greece during the passing of the storm system.

As of April 19, officials have issued the following weather warnings across Greece:

• Orange heavy rain and thunderstorm warnings (the middle level on a three-tier scale): Central and East Macedonia, the Cyclades Islands, the Dodecanese Islands, East Sterea and Evia, Epirus, the Ionian Islands, the North East Aegean Islands, Thessaly, West Peloponnese, and West Sterea regions.

• Orange snowfall warnings: Central and East Macedonia, Epirus, and West Sterea regions.

• Orange strong wind warnings: Central Macedonia and the Ionian Islands regions.

• Yellow heavy rain and thunderstorm warnings: Attica, Crete, East Peloponnese, and West Macedonia regions.

• Yellow snowfall warnings: West Macedonia Region.

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 could render some bridges or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities may temporarily close some low-lying routes that become inundated by floodwaters. Flight delays and cancellations at airports are possible. Authorities may temporarily suspend port operations or close beach fronts along the east coast if strong winds trigger hazardous sea conditions.

Localized business disruptions are possible 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.