Following a mild December, the first shot of frigid air will set the stage for a winter storm across the parts of the Balkan Peninsula from this weekend into Monday. Snow and ice could cause major travel delays.
Prior to the arrival of the storm, the coldest air since last winter has settled across much of the Balkan Peninsula. This cold air will result in most of the precipitation falling as snow or a wintry mix away from the Adriatic and Mediterranean seas.
The storm will move across Italy on Saturday, bringing a chilly rain to central and northern areas. It will be cold enough for the rain to mix with snow in northern Italy, from Torino to Milan and Treviso. Any accumulating snowfall will be limited to the higher elevations.
Along the Adriatic coast a moderate to heavy rain is expected Saturday night and Sunday elevating the risk for localized flash flooding from Slovenia to western Greece. Rainfall will generally average 25-50 mm (1-2 inches) with some areas seeing more than 75 mm (3 inches) of rain by Monday.
From the Dinaric Alps eastward the cold air will result in the first widespread accumulating snowfall since last winter from Sarajevo to Belgrade and Bucharest.
The winter storm will arrive Saturday night and continue on Sunday across the entire region. Snowfall will last into Monday morning in eastern Bulgaria and Romania.
A general 8-15 cm (3-6 inches) is expected from Sarajevo and Zagreb to Belgrade and Bucharest.
A swath of heavier snow is expected from southern Serbia into northern and central Bulgaria where 15-30 cm (6-12 inches) of snow is possible. This area includes Sofia.
Snow will fall as far south as the mountains of northern Greece, while rain falls over the lower elevations.
A weaker second storm will bring additional precipitation to the Balkans on Tuesday; however, milder air will cause the snow to transition to ice and rain before ending on Wednesday.