11 Jan 2021 | 06:55 PM UTC
Europe: Storms to bring daily rounds of rain, mountain snow to eastern Balkan region Jan. 11-13
Storm system to bring rain and snow to Europe's Balkan region Jan. 11-13. Transport and utility disruptions possible.
Event
A low-pressure system will bring rounds of snow and rain, including thunderstorms, to eastern portions of Europe's Balkan region through Jan. 14. The affected areas include western Turkey, Bulgaria, far southern Serbia, southern Kosovo, Albania, North Macedonia, and northern and central Greece. Forecast models indicate initial rounds of rain will develop in western Greece, southern Serbia, and North Macedonia the evening of Jan. 11 and will spread eastward Jan. 12. Intense rounds of rain and thunderstorms will develop in southeastern Bulgaria and western Turkey in the afternoon of Jan. 12 and will linger until Jan. 13.
Government Advisories
As of Jan. 11, orange-level warnings - the second-highest on a four-tiered scale - for rain, snow, and thunderstorms are in effect for northern Greece, southern Bulgaria, and southern Serbia. Meanwhile, yellow-level warnings have been issued for the rest of the Balkan region over the coming days due to strong winds, snow, heavy rain, and storms. Authorities will likely expand coverage of the advisories as the systems approach and weather conditions change over the coming days.
Hazardous Conditions
Forecast models indicate rainfall totals of 5-13 cm (2-5 inches) are expected in the hardest-hit areas over the coming days including northern Greece, southeastern Bulgaria, and northwestern Turkey, including Istanbul. Slightly lower rainfall totals of 2.5-5 cm (1-2 inches) are forecast farther west in the Balkan region toward the Ionian Sea.
Flash and areal flooding is possible, especially in areas where the soil is saturated from previous storm systems. Such flooding could occur in low-lying communities near watercourses and other bodies of water, as well as 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. Where precipitation falls as snow, 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. The adverse weather conditions could cause power outages throughout the affected area through at least Jan. 13.
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. Authorities could close mountain passes and tunnels as a precautionary measure during periods of intense snowfall.
The disruptive weather will likely cause some delays and cancellations at regional airports, including those serving Athens (ATH), Istanbul (IST, SAW), Antalya (AYT), Izmir (ADB), and Sofia (SOF). Authorities may temporarily suspend port operations if strong winds trigger hazardous sea conditions, impacting freight and passenger maritime traffic in the Sea of Crete, as well as the Ionian, Black, Aegean, and Mediterranean seas. 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, could persist well after conditions have improved; it could take days before any floodwaters recede and/or debris is cleared. 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 prior to travel in the affected area through at least Jan. 13. Seek updated information on road conditions before driving or routing shipments through areas where severe weather is forecast; plan for possible supply chain disruptions if routing shipments through 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 case prolonged electricity outages occur.
