The headword, perhaps (though not necessarily) extracted from the quotation given, is a masculine noun in the nominative singular; see again at pi 2269, and generally LSJ s.v., where the range of extreme meteorological conditions it can cover (paralleled in the cognate verb: pi 2266) is summarised as 'hurricane or waterspout attended with lightning'. With no one-word equivalent in English, its sense has to be determined by context.
[1] The headword is similarly glossed by ps.-Zonaras 1572.24. [In her critical apparatus Adler reports that mss FV omit a)straph/.]
[2] Greek Anthology 7.174.5-6 (Erucius), the epitaph to the cowherd Therimachus; cf. Gow and Page (248-249) and another excerpt from this epigram at beta 348.