Southern Europe: Adverse weather forecast across parts of Bulgaria, Greece, and North Macedonia through at least Jan. 11

Event

A combination of heavy rainfall, thunderstorms, and strong winds are forecast across parts of Bulgaria, Greece, and North Macedonia through at least Jan. 11. Snowfall and sleet are also possible over mountainous parts of the region. Heavy downpours could trigger flooding in low-lying areas and strong winds may cause property damage and power outages. Thunderstorms may be accompanied by lightning and hail.

As of Jan. 9, the Bulgarian National Institute of Meteorology and Hydrology (NIMH) has issued the following weather warnings Jan 10:

• Orange heavy rainfall warnings (the middle level in a three-tier scale): Haskovo, Kardzhali, and Smolyan provinces.

• Orange strong wind warnings: Haskovo and Kardzhali provinces.

• Yellow heavy rainfall warnings: Blagoevgrad, Gabrovo, Kyustendil, Lovech, Montana, Pazardzhik, Pernik, Plovdiv, Shumen, Sliven, Sofia City, Sofia, Stara Zagora, Targovishte, Veliko Tarnovo, Vratsa, and Yambol provinces.

• Yellow strong wind warnings: Yambol Province.

• Yellow strong wind and rough sea warnings: Off the coasts of Burgas, Dobrich, and Varna provinces.

The Hellenic National Meteorological Institute has issued an orange level (the middle level on a three-tier scale) Emergency Deterioration of Weather Bulletin, warning of heavy rainfall and strong winds especially in coastal regions through Jan. 11. The adverse weather is forecast to affect the northern Ionian Islands and parts of Epirus Region from late Jan. 9 before spreading over many parts of the country Jan. 10. Snowfall is also possible over elevated areas of the mainland Jan. 10. The adverse weather will continue over the Dodecanese Islands Jan. 11. As of Jan. 9, authorities have issued orange thunderstorm warnings over the Ionian Islands and Epirus Region, as well as yellow thunderstorm warnings for West Sterea Region. Yellow strong wind warnings have also been issued for the Cyclades, Ionian, and Northeastern Aegean Islands.

North Macedonia's Hydrometeorological Service has issued a weather warning across the country. Rain with snow over mountainous areas is expected to spread from the west overnight Jan. 9-10 before becoming more widespread and intense across the country Jan. 10. The rain is expected to transition to snow in lower elevations for some areas late Jan. 10. The heavy precipitation is forecast to be accompanied by moderate-to-strong winds.

Authorities will likely issue new alerts or update/rescind existing advisories as weather conditions change over the coming days.

Hazardous Conditions
The storms could produce rounds of heavy precipitation (including rain and snow), strong winds, and isolated thunderstorm activity. Where precipitation falls as rain, flash and areal flooding is possible. Such flooding is possible in low-lying communities near watercourses and other large bodies of water and in urban areas with easily overwhelmed stormwater drainage systems. Sites located downstream of large reservoirs may be subject to flash flooding after relatively short periods of intense rainfall.

Precipitation could fall as snow in higher elevations over the coming days. Wind gusts could cause blowing and drifting snow; decreased visibility is likely in mountainous areas. Rain-induced landslides cannot be discounted in areas of elevated terrain; there is also the possibility of avalanches in mountainous areas where the snowpack has become unstable due to heavy snowfall. Power outages could occur throughout the affected area.

Transport
Floodwaters and related debris may render some bridges, rail networks, or roadways impassable, impacting overland travel in and around the affected area. Flooding in urban areas could also result in significant traffic congestion. Heavy snow will likely make driving hazardous in some areas; authorities could implement temporary road closures or detours in such locations. Mountain passes and tunnels could be closed as a precautionary measure during periods of intense snowfall.

The disruptive weather will likely cause some delays and cancellations at airports in the region. Authorities may temporarily suspend port operations in coastal areas if strong winds trigger hazardous sea conditions, impacting freight and passenger maritime traffic. Flooding could block regional rail lines; freight and passenger train delays and cancellations are possible in areas that see heavy rainfall and potential track blockages.

Disruptions triggered by inclement weather and resultant hazards, such as flooding or avalanches, 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.

Advice

Monitor local media for weather-related updates and advisories. Confirm all transport reservations and business arrangements before traveling in the affected area. Seek updated information on road conditions before driving or routing shipments through areas where severe weather is forecast; plan for possible supply chain disruptions throughout the affected areas. Stay away from elevated streams, creeks, and other watercourses that are prone to flash flooding. Do not attempt to navigate flooded roadways. Exercise caution in elevated terrain due to the threat of landslides, as well as mountainous regions where avalanches pose a threat. Charge battery-powered devices in the case of prolonged electricity outages.

Resources

Meteo Alarm
Bulgaria National Institute of Meteorology and Hydrology (NIMH)
Greece Hellenic National Meteorological Institute
North Macedonia Hydrometeorological Service