After yesterday's thundery showers, we may be in for heavy rain later today. For the region's desperate farmers, it is not before time, reports STEPHEN LEWIS

There just may be a rainstorm later today. Another one. A proper one.

The Met Office is forecasting that after weeks of hot dry weather - which broke only with the thundery showers last night and this morning - the dry spell could be about to properly end this afternoon.

It is predicting widespread thunderstorms across the York area this afternoon and evening - with possibly torrential rain and even flash flooding.

It can't come too soon for beef farmer Mike Powley.

Mike keeps a herd of almost 100 beef cows on 320 acres at Green Hammerton. At the moment, his farm is sustaining 90 cows, each with a young calf born in March or April, plus some yearling heiffers born last year.

But because of the prolonged drought we have faced in the last couple of months, he's worried about how he is going to feed them.

Normally they would be eating grass through to October. Then, as the weather gets wetter and cooler, he'd bring them in and start them on the silage stored to get them through the winter.

But because of the dry weather his fields are parched, the grass brown and withered. He's having to start feeding them on the silage already: which means he won't have enough to see them through the winter.

"What do you do? You pray for rain," he says.

Mike has been farming at Green Hammerton for 31 years. But the weather conditions we've had this year have been unprecedented, he says. "It is the driest it has been in those 31 years, by far." The occasional localised thunderstorms have so far all missed his land.

Ironically, the problem is compounded by the fact that, earlier in the year, it was so wet and cold. That meant his silage was slow to get started - so he has a smaller crop than usual.

A smaller silage crop coupled with the fact his cows will start eating it two months earlier adds up to a big worry.

It isn't just the shortage of grass and silage that worries him, however. He also grows spring beans to fatten his calves for market. The best that can be said about that crop at the moment is that it's still alive.

"It's just hanging in there," he says. But it needs rain soon.

The rain that fell last night and this morning swasn't enough tio make uop for the weeks of drought. If the promised heavy rain doesn't come later today - and be followed up by more rain over the next few days - he'll face the prospect of having to let some of his 15-year-old heiffers go to market sooner than he would like - simply because he can't feed them. They would normally go in September or October, to be fattened ready for the Christmas market. "But I might have to send them early," he says.

That would mean they wouldn't have been fattened up so much, so they'd be worth less. And it could also mean a short-term glut of red meat on the market as other farmers do the same - potentially forcing down prices even further.

That might be good news, in the short term at least, for meat-eaters. But it will hit Mike's bank balance hard. After a year of hard work, if we don't get rain soon, he stands to make a loss this year. In other words, instead of earning money for a year's hard graft, he'll lose it. "You imagine telling someone 'you work for 12 months, and then instead of getting paid you have to pay me'," he says.

He doesn't have insurance to fall back on, because he didn't take insurance out - not for drought, anyway. He'd be covered against thunder or lightning. "But we don't get droughts!"

Mike isn't the only farmer in the region to have been hit hard by the dry weather.

Earlier in the week, Crockey Hill carrot farmer Rodger Hobson warned his carrot harvest could be 30 per cent down on last year - and that there could be a carrot shortage at Christmas.

And Amy Morrison of the National Farmers Union (NFU) says the drought will affect crop yields across the board.

The outlook for wheat crops is variable, she says, depending on what soils they are planted in: light, sandy soil holds water less well, so wheat crops planted in such soils have been struggling.

Crops such as celery, leeks, carrots and potatoes, however, will all have reduced yields because of the drought, she says. And the shortage of fodder and straw bedding will hit all livestock and dairy farmers as the year goes on. "It is not a good situation," she said.

Richard Bramley, who has a mixed arable farm at Kelfield near Selby, agrees.

His winter wheat crop, which he is about to start cutting, has matured very quickly because of all the sun. It has done OK because of the rain earlier in the year. "It won't be a bumper crop, but it will be OK."

If we don't get more rain soon, however - proper, sustained rain - he's worried about the spring wheat and barley crops he will be harvesting in the next couple of weeks, earlier than usual because of the hot, dry weather.

They went in the ground in late April - since when there has been hardly any rain to nourish them.

He's also worried about this year's potato and sugar beet crops.

They were planted late, in May - especially late in the case of his sugar beet, and again ironically it was because before that the ground was too wet.

Now it is too dry.

"If it doesn't rain soon, we won't be able to get the crop out of the ground," he says. "It is set as hard as concrete."

Then there's next year's oil seed rape crop, which should be going in the ground soon. Again, if we don't get proper amounts of rain soon, the crop just won't get the start it needs.

If we do get the promised thunderstorms and torrential rain later today, that would certainly help. Too much water too quickly can cause flooding, says Richard, much of whose land is near the River Ouse. But because his land is so dry, it would need to be a very heavy, prolonged downpour.

He is, however, worried about the possibility of hail, which some forecasters have been predicting. That could flatten crops, and knock away ears of grain. "That could be a catastrophe."

But mainly, like Mike Powley, he'll just be praying for more rain.

He's been farming for almost 30 years. "And this is the driest I have ever known," he said.

A few more inches of rain later today probably won't be enough, Mike says. We need prolonged, sustained rain if things are to get back to anything like normal.

Join in prayers for a rainy August, anyone?

What has caused the extreme weather?

The extreme weather we've had this year so far - the 'Beast from the East' and flooding earlier in the year, followed by months of dry, hot weather, followed by the preduicted torrential rain today - may well be partly the result of climate change.

Forecaster Mario Cuellar of the Meteo Group in London says climate change models predict more of precisely the kind of weather extremes we have seen this year - cold, wet winters and hot, dry summers. The hot, dry spell has not been confined to Britain: it has stretched across the northern hemisphere, from the US to Sweden, central Europe and Japan in the far east.

Such hot, dry summers are expected to become more common in future, because of climate change, Mr Cuellar says.

This year's extreme hot weather has been compounded by a weak jet stream, which has moved well to the north of the UK and has allowed hot, dry air from Africa to push north. But the weak jet stream itself could be a consequence of climate change, Mr Cuellar says. The jet stream is caused by temperature differentials between the north pole and the equator. "When there is less ice on the pole, the jet stream tends to become weak."

Like other forecasters, Mr Cuellar predicts that the weather will break today, with thunderstorms and bursts of heavy rain across the UK.

But even if we get the thunder and rain forecasters are predicting, we should brace ourselves for more hot, dry summers in the future. It won't happen every year - but climate change predicts such summers will become more frequent in future.