Excessive snowfall and severe blizzard conditions across SW Slovenia and NW Croatia tonight into tomorrow morning, Nov 20th
The ongoing pattern across the Mediterranean supports significant snowfall across north Italy, Slovenia, parts of Croatia and south Austria in the next 24-36 hours. Snow expected also in the low-lying areas.
The large cutoff low over W-CNTRL Mediterranean will be associated with a large and relatively deep surface low over the central Mediterranean. It will result in a strong low level wind field across much of the central and northern Mediterranean. Strong southerly and southeasterly winds across southern and central Adriatic, which will cause torrential rainfall along the coastal region there, turn into northeasterly Bora winds across northern Croatia and Slovenia, advecting cold air from the east. Meanwhile, mid-level southwesterly flow will continue advecting moist airmass into the region, resulting in significant snowfall.
The 5 maps below show the sequence of snowfall across S Austria, Slovenia and Croatia. Snowfall begins late on Monday evening, with the most intense snowfall in the Tuesday morning hours. By mid-morning warm air advection into the northern Adriatic region intensifies, again pushing rainfall further inland and producing ice pellet precipitation across the western Dinarides.
Expect up to 5-10 cm of snowfall in the elevated terrain of southern Austria. Up to 20 cm of fresh snow is expected at higher elevations of the southern Alpine slopes in north Italy. Up to about 10-30 cm of snow is expected along the elevated terrain of the Dinarides in western Slovenia, 10-15 cm in the Alps and several centimeters in most of the remainder of the country. Up to 20-30 cm is expected in Gorski Kotar in NW Croatia.
Intense Bora (Burja/Bura) winds gusting 120-140 km/h and locally above 150 km/h will produce intense blizzard conditions with zero visibility and major snow drifts. Driving conditions in W Slovenia and NW Croatia will be extremely difficult and potentially very dangerous.