For this headword in its (common) applied meaning of fortune -- good or bad -- see already sigma 1407 and sigma 1408. The present entry (which, Adler reports, is part of sigma 1408 in four of the mss) presents an instance of it in a literal, etymological sense.
[1] George of Pisidia, Heraclias 3 fr. 10 Tartaglia, line 1. In his footnote to this fragment, Quercius (J.M. Querci) notes (cf. Migne, PG 92.1748 n. 145) that it is from an unknown text, but cautions that it might not be literally about snowdrifts. He suggests rather that this could be the poet's metaphor for the cause of a surprisingly cool and refreshing change in the weather, described by Theophanes Confessor, which Heraclius's army once encountered during their summer campaign in Persia; cf. de Boor (307.21). Tartaglia (226-227) does not repeat Querci's speculation. On Heraclius, see generally eta 465.