(Decanter) - Hailstorms continue to batter French vineyards, this time in the heart of Alsatian wine country, with up to 60% damages reported in parts of Southern Alsace.

The storm, which occurred on the afternoon of Tuesday 6 August saw hailstones, some the size of ping-pong balls, hitting windscreens and roofs and threatening this year's harvest.

Hardest hit were vineyards along the plains of Turckheim and Colmar, although rain mixed with hail mitigated the impact on sloped grand cru vineyards, according to a preliminary assessment by Paul McKirdy, cellarmaster at the famous Zind Humbrecht domain in Turckheim.

‘Had it been just hailstones, it would be much worse,’ he said.

McKirdy estimates that Zind Humbrecht suffered about 20% potential damage to its vines - including parts of the famous Brand grand cru vineyard.

Amélie Buecher of Vignoble des 2 Lunes in Wettolsheim said the hail was striking enough that people had to close their shutters; ‘I saw hailstones the size of ping-pong balls; we were very worried.’

Buecher reported ‘light damage’ in the Hengst grand cru vineyard, from which other domains including Josmeyer and Zind Humbrecht make wines.