The cows have been been washed and the human cannon is in place as Malvern's Three Counties Show prepares for the arrival of Charles and Camilla today.

The Prince of Wales and the Duchess of Cornwall were spending around four hours watching displays, visiting stands and presenting awards on the opening day of the annual Three Counties Show.

Overnight rain had made conditions more suitable for wellies than walkabouts, but with most of the thoroughfares on the 70-acre site now down to hard roadways, there were unlikely to be logistical problems for the royal programme.

It will be the first time since 1978 that Prince Charles has been to the region's top agricultural event and his visit marks the 50th show to be held on the permanent site at Blackmore, set against the spectacular backdrop of the Malvern Hills.

"It is a great honour to welcome their royal highnesses to Malvern, particularly in such a significant year," said Nick Vincent, chief executive of the Three Counties Agricultural Society, which runs the show.

It will also be a big day for Three Counties receptionist of 17 years, Mary Lynes from Malvern Link, who will present the Duchess with a posy at the end of her visit.

"I've been practising my curtsy all week," she laughed. "I'm absolutely delighted to have been chosen."

The royal itinerary includes tours of the food and wine fair and the inaugural cheese and dairy produce show, as well as the presentation of long service awards to some of the Three Counties' longest-serving farm and estate workers.

About 100,000 visitors from all over the UK and abroad are expected at the three-day event before it closes at 6pm on Sunday night.

The weather for the show is forecast to improve as the weekend progresses.

"I think Sunday will be the best day," said Worcester weather guru Paul Damari. "By then it should be mostly dry and bright with only the odd shower.

"Friday and Saturday are likely to be a mix of sunny periods and showers, the odd one possibly heavy and thundery. But the temperatures will be comfortable at 17-19C/63-66F."