טאָרנע
'Tarnów (city in western Galicia, southern Poland)'

ETYMOLOGY

Herzog writes that in CY טאָרנע was rendered Turne because the word entered Yiddish from a Polish dialect where the vowel was /o/, which was then subject to the regular shift o > u in SY.
{Herzog 1964: 117-119}
However, as Beider notes, Tūrne may be from German (the MHG or ENHG version of Tarnau), rather than directly from Polish.
Beider suggests that the name was borrowed from Old Polish, before the 16th c., when the first vowel of Tarnów was long /aː/ (perhaps the vowel was lengthened in a stressed syllable before /r/ and a second consonant). The vowel merged with A₂ and had the corresponding different realizations in Yiddish dialects (e.g., "Tūrne" in CY).

TU:NE [Yiddishland, Paul Glasser}

CENTRAL

mᵻ-dᵻ vaːsɬ, ka tarnuf מיט די ווײַסל קיין טאַרנאָוו {Warsaw, Geller 2001: 263}