16/02/2014 Newsround

Hi guys, Ayshah here, with the weekend stories you need to know.

Coming up: It's been called BMXing on snow - we'll tell you how Great

Britain got on in the awesome Snowboard Cross.

And from snowboards to surfboards - we'll bring you the curly tale of

the pig who rides the waves. This is Newsround.

So, first - all this week we've been telling you about some truly

extraordinary weather conditions that have been causing terrible

problems, not just here, but in America, too. So, what's causing all

this weird weather? As I've been finding out, it's all to do with a

global wind, high above us: the jet stream.

In the wind and rain. In the US, they're in the grip of a cold winter

that shows no of stopping. Scientists don't think this is just

a coincidence. They believe the recent warming of the Arctic is

driving weather conditions here. That is this current, here, in red.

It's called the Jetstream. It has caused months of heavy rain and

storms for us, and extreme cold for America. This scientist has been

studying the Jetstream, and things we could see more of the same in the

future. I think we should expect is to occur

more frequently. It's being these wavy patterns in the Jetstream and

that tends to result in weather conditions being very persistent in

one place. Early to judge whether the

Jetstream's change in shape is permanent. As we may have to get

used to whether that stays the same for weeks or even months.

In this country, we've seen severe flooding affecting thousands of

people throughout the south of England, while hurricane-force

storms have battered the coastlines of much of Britain in recent days.

Meanwhile, over in America, they're suffering a prolonged, bitterly cold

winter which is showing no sign of calming down. Back here in Britain,

the Prime Minister has warned that flooding misery is likely to

continue for millions of people, despite a break in the bad weather.

David Cameron said that many places in southern England, where the

ground is already soaked, may see further flooding. One of the biggest

threats is not from rivers bursting their banks, but from water

underground, coming to the surface. Check this out.

One of the reasons we are seeing so much flooding is ground water

flooding. This happens when water rises from rocks under the ground,

and comes out on the ground service. -- surface. When enough

rain in these areas, what keeps moving down beyond the surface. It

tends to move from higher ground to lower ground. When we have a lot of

rain, water starts to come out of the ground surface in places that

are usually drive. We call this ground water flooding. It takes

longer to go away and flooding from rivers. It can last for weeks or

even months. Next, we're off to Russia and the

Sochi Winter Games. Today, we've been enjoying a thrill-packed sport

that's been likened to BMXing on snow - it's the snowboard cross. Six

riders carve down the course, braving huge jumps and sharp

corners, and with everyone so close together you can have some nasty

crashes. Team GB's Zoe Gillings did make the semi-finals this morning

and came within just a few centimetres of making the final -

but unfortunately she just missed out. She did finish in the top ten

overall, though. Well, you've been telling us about

your Sochi highlights over on the Newsround website. Ashleigh from

Boston in Lincolnshire says, my highlight has been the speed

skating, it's amazing how fast they go without falling over! Farsya in

Birmingham said, I never knew what curling was before, but now I want

to try it Thanks so much for all those

comments, keep them coming in. Speaking of the curling then,

Britain's men's curling team were beaten 7-6 in their second to last

round robin match with Norway this morning, so they're not guaranteed a

semifinal place yet. The match went down to the final end of the game

with the scores level at 6-all, but the Norwegians won with the final

stone. Team GB can still make the semis if they beat China tomorrow

afternoon. Britain's women play their last two matches tomorrow as

well. In today's matches, Arsenal will be

hoping to avoid another scoreline like this when they face Liverpool

again in the big four o'clock showdown. In the afternoon's other

games Everton face Swansea in the early kick off at 1.30PM and

Sheffield United play Nottingham Forest at 3PM.

Next up, what are all these people up to behind me? Well it's a world

record attempt of course! Thousands of young Pakistanis braved heavy

rainfall in the city of Lahore yesterday trying to break the world

record for the largest human flag. More than 29,000 students made a

giant version of their national flag out of pieces of card - and they

think they've set a new record! Top work, guys!

Last up, a curly tale of a surfing pig. No, I'm not telling porkies.

This water-loving piglet called Kama loves to go swimming with his owner

in America. Is Here he is catching the waves at Hawaii's Sandy beach.

The pigs love of surfing started when he used to swim with his owner

in a pool in the back garden, and look at him now.

I'll be back with your last bulletin of the day before 2PM.