Heavy Hoar Frost/Hard Rime Along the Eastern Slopes of Mount Javornik (1242m a.s.l), Northern Coastal/Internal Karst Region Border, Hrušica/Ad Pirum Forest (Selva di Piro, I), Slovenia
18-december-2018: this is "Mountain Hoar Frost" or "Hard Rime" ("Calabrosa" in Italian) and it forms on mounts and mountain ranges windward slopes exposed to very humid and cold currents forcibly rise from sea, lakes, soaked valleys and plains (Stau Effect), so it's composed by Wind (generally Bora/Burja in this Area) + Freezing Fog (that are Low Orographic Clouds in Stau phenomenon).
"Valley Hoar Frost" ("Galaverna" in Italian), instead, forms in the valley bottoms and in the lowlands with CALM of wind, thermal inversion and irradiation freezing fog.
In this case, on the Dinaric Alps mountains of the Karst watershed, Bora comes very wet for the rise of the currents from drenched/soaked plains of the Sava and Ljubljanica rivers.
Bora wind is damp and continuous on the interior side of the Karst Region (watershed dewlaps Adriatic/Black Sea), while it is dry and very gusty on the coastal one (up to 183kmph in Trieste at 11-02-2012).
Heavy Hoar Frost/Hard Rime Along the Eastern Slopes of Mount Javornik (1242m a.s.l), Northern Coastal/Internal Karst Region Border, Hrušica/Ad Pirum Forest (Selva di Piro, I), Slovenia
18-december-2018: this is "Mountain Hoar Frost" or "Hard Rime" ("Calabrosa" in Italian) and it forms on mounts and mountain ranges windward slopes exposed to very humid and cold currents forcibly rise from sea, lakes, soaked valleys and plains (Stau Effect), so it's composed by Wind (generally Bora/Burja in this Area) + Freezing Fog (that are Low Orographic Clouds in Stau phenomenon).
"Valley Hoar Frost" ("Galaverna" in Italian), instead, forms in the valley bottoms and in the lowlands with CALM of wind, thermal inversion and irradiation freezing fog.
In this case, on the Dinaric Alps mountains of the Karst watershed, Bora comes very wet for the rise of the currents from drenched/soaked plains of the Sava and Ljubljanica rivers.
Bora wind is damp and continuous on the interior side of the Karst Region (watershed dewlaps Adriatic/Black Sea), while it is dry and very gusty on the coastal one (up to 183kmph in Trieste at 11-02-2012).