Greece: Adverse weather forecast across central, eastern, southern, and western regions through at least Nov. 23

Severe weather is forecast across much of central, eastern, southern, and western Greece through at least Nov. 23. The Hellenic National Meteorological Service has issued an orange level (the middle level on a three-tier scale) Emergency Deterioration of Weather Bulletin, warning that heavy rainfall and thunderstorms will move into western regions late Nov. 21 before spreading across southern and eastern regions Nov. 22. The system is expected to weaken late Nov. 22-early Nov. 23. Strong wind gusts, lightning, and possible hail may accompany storms. Heavy downpours associated with the storms may trigger flooding in low-lying areas, and strong winds could cause property damage and power outages.

As of Nov 21, authorities have issued the following weather warnings across the affected area:

• Orange heavy rainfall and thunderstorm warnings: Crete, Cyclades Islands, Dodecanese Islands, Epirus, Ionian Islands, NorthEast Aegean Islands, West Peloponnese, and West Sterea regions

• Yellow heavy rainfall and thunderstorm warnings: Across the rest of the affected area

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 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.

The severe weather could contribute to transport disruptions throughout the region. Traffic and commercial trucking delays might occur along regional highways. Flooding downpours could inundate some low-lying roads in areas with poor drainage. Strong winds might also pose a hazard to high-profile vehicles. Hazardous weather conditions might cause flight delays and cancellations at airports in affected areas. Authorities may temporarily suspend port operations or close beach fronts if strong winds trigger hazardous sea conditions.