Vintage port producers in the Douro Valley may have to accept that the warm spring and dry summer endured this year are set to become the norm.

This is the view of Antonio Magalhaes, head viticulturist for The Fladgate Partnership, who believes that parts of this year "looked like the future".

Speaking to the Drinks Business, he expressed concern that the Douro will now see very wet winters and drier springs on a regular basis.

"In April the average temperature was four degrees Celsius higher than normal and May was three degrees higher," Mr Magalhaes explained, adding that as a result the vines flowered earlier than they should.

Rainfall was also another major problem, as with no precipitation for four months growers simply did not have enough water to help the grapes ripen.

When it did rain, Mr Magalhaes explained that it sent everything "haywire".

"We had four months with no rain, then two sets of rain in the third week of August and [start of] September," he said.

"Three days afterwards the berries tasted of nothing and dropped by 1.5 Baumes. If we'd had more rain things would have collapsed."

It was a feeling of frustration felt by many others trying to create vintage port wines in the Douro.

In a blog post as early as July, Symington Family Estates viticulturist Miles Edlmann explained that a "thermal onslaught" bringing temperatures in excess of 40 degrees Celsius had burned and desiccated grapes at the vineyard.

Hailstorms only compounded what was a "calamitous" period for the vineyard, Mr Edlmann added.

The suggestion that such harsh weather conditions may become the norm is further bad news for producers in Portugal.

Protests from Douro growers turned violent earlier this month as desperate vintners expressed anger at the Instituto do Vinho do Porto's decision to reduce permitted port production in the region by around 30 per cent for 2011.