prairies, hello. this is bbc news. the headlines: 36 militants, from the group which calls itself islamic state, are thought to have been killed in afghanistan, after a us military strike with a weapon known as the "mother of all bombs". a british woman in her 20s has been stabbed to death injerusalem. israeli police say she was attacked on a tram by a palestinian man who's been arrested. two of england's biggest teaching unions are warning that schools are facing their worst funding cuts in 20 years. security's improved at the online booking site air bnb, after a bbc investigation finds scammers burgling homes. thanks for your company this afternoon. now on bbc news weather world, and this time nick miller and sarah keith—lucas have been to northern ireland to look at the relationship been aviation and the weather. this time on weather world we are in northern ireland airside at belfast international airport.

we are going behind the scenes to find out what it takes to keep these planes flying and you and i safe, whatever the weather. also on weather world, devastation and deadly floods in south america. but some dramatic escapes too after months of heavy rain leave towns under water. and mud as landslides kill hundreds. weather bomb, the storm so strong they hold a unique place in weather science. and have taken california from drought to deluge with the ground giving way. and extreme heat, wild fires as parts of australia endure their hottest summer. plus, you have some history there. taking the temperature, i will be opening the archives of one of the world's longest running weather observations and watching how it is still being done today.

i will be taking a trip back to my own family history and aviation‘s past to see how some of today's technology was born. welcome to weather world at belfast international airport. 13 miles north—west of the city of belfast this site was first established as a military base in the first world war. since then, it's grown to become the busiest airport in northern ireland with over five million passengers travelling through it last year. the airport serves other uk and european destinations, plus there are flights to the usa. weather and airports, so much can go wrong, can't it? it's an interesting relationship, thunder storms, fog, wind, snow, someone that knows all about those weather challenge is michael, the general manager of air

traffic control here. hello, michael. hi. is there a day when you are not thinking about the weather? no, every day, every day controllers come into work they're obviously thinking about the weather. the surface wind is very important in terms of deciding what's the direction of runway for take—off and landing. interested in the cloud, the type of precipitation. we are interested in knowing all we need to. there is something specific about the airport here at belfast which is about the weather and increases your flexibility. yeah, we are one of the only remaining uk airports that still operates across runway. it faces east—west. we have a cross runway which sits at right angles, from the main runway. it's orientated more or less north—south. during the autumn when we get low pressures coming across the conflict

—— the atlantic, we get strong southerly gales and a pilot's preference is is to land into wind, when the cross wind gets roughly around 30 knots, the pilots will opt to take the other runway for a safer approach and take—off. weather is so important and sarah's in the control tower now to take a look at how they get the very latest weather information here. this is the main weather system used here in the air traffic control centre. all the numbers and figures on the screen correspondent to continuous weather data that's collected. we record things like wind direction and speed, visibility, any significant weather around as well as importantly cloud amounts and heights too. every half an hour a report is issued. that will help pilots make operational decisions about whether it is safe to land or whether they might need to divert to another airport. when the weather gets rough, the landings get tough. this plane struggles to maintain a steady approach to manchester airport in february, in the uk's fourth named

storm of the season. winds of up to ioomph hit the uk as storm doris blows in. as you see the foam hitting me from the sea that it definitely has materialised, gusts here are so powerful i can't even face in the direction of the wind is coming from. as reporters tried to remain upright, some trees failed. a lucky escape here for a driving instructor. but the storm did claim the life of a woman hit by falling debris and it wasn't just the wind doing the damage. there was heavy snow too here in scotland. storm doris was an area of low pressure that underwent explosive genesis so strengthening quickly. storms like this have become known as weather bombs. life—threatening storm... this was another. a major snow storm hits the north—east usa in march bringing

to an abrupt end what had been a mild start to the year. and for the first time in 33 years in new york, march was colder than february. there is cold and there is frozen solid. this house became encased in ice after strong winds blew water from lake ontario over it that froze. amazingly when the ice melted these pictures show the house emerging virtually unscathed. europe's coldest winter month was january. with the unusual sight of snow on greek island beaches. but the bitterly cold weather brought fresh misery for migrants at camps such as these in the balkans. then disaster in italy. a mountain hotel buried by an avalanche, 29 people are killed but amazingly, some survive, rescued more than two days later. oh my god! tornado season in the usa peaks in spring but this

is february in louisiana. and new orleans is hit with its strongest tornado on record but worst came even earlier. a january outbreak of tornado sweeps through south—eastern states leaving total devastation and 20 dead. more than died in tornados in the usa in the whole of last year. it's a beautiful day here at belfast international airport today but visibility is not always this good. in fact, the airport can be prone to seeing dense fog. michael is going tojoin me now and can you explain just how do you land a plane when you can't see the runway? certainly. we have an instrument landing system at the airport, part of is system is the glide path.

it sends a signal to the pilot and tells him if he is too high or too low as he makes the approach. we have another signal at the other end of the runway, the localiser, and it tells the pilot if he is left or right of centre line. the combination of the two, left right, up, down, safety guides the aircraft to land. wonderful. we have had a look at what it looks like from the ground, i would love to see is how this instrument landing system works from up in the skies. shall we take a look? absolutely, let's go. michael, we are up in the air. can you explain to us a little about how this instrument landing system, the ils works from the pilot's perspective up here? absolutely. you can see the pilot gets the distance from touchdown. it's displayed at all times in the cockpit. so he knows how far he is from touchdown. you can see from the ils signal at the moment the needle is to the left. that means the aircraft needs to fly left to get on track. i suppose in poor visibility conditions, in thick fog or blowing snow the pilot would rely upon this instrument? absolutely.

and the system at aldergrove allows the aircraft to auto land in those sort of conditions. we took to the skies thanks to air ambulance northern ireland, but every commercial airline has an instrument landing system on board, so, no matter where in the world you make your landing, the guidance given to your pilot will be exactly the same. it takes an awful lot of power to power the ils, all this kit, and also an entire airport but you might be surprised to hear where that power comes from. let's head down to nick on the ground to explain more. infact, sarah, belfast airport requires 1.8 megawatts of electricity every day. and they get it right here, right next to the airport from tens of thousands of solar panels, and on a sunny day this gives the airport all the power it needs. over here, if you listen carefully, that whiny sound is the power being made, because even though it's

cloudy there is still solar energy coming through converted through this inverter. alan is the operations manager here at the airport. how important is this farm, and has it become to the airport? it's been a great success for us. the first nine months it produced 27% of the energy that we use on airport. it still is producing on a day like this, on a really good day absolutely everything on airport from radars to instrument landing systems, security systems, baggage systems, everything on airport is running on it. it is still producing excess for the grid. we can see what it's been doing for the airport today through this display unit here. the sun has come out occasionally today. yes, this shows the last 2a hours of production with it. last night around sundown it was still producing, then it dropped off through the night period.

from dawn, it's gone up. we had a rainy period here this morning. it still is producing 250, 500 kilowatts. at peak time when the sun has come out it's producing 1500. so it's working very well. even for northern ireland. i wish you many more blue sky days. thank you very much. bbc weather watchers know cloudy days have their pluses too. and theyjust got a whole lot more interesting thanks to the release in march of an updated cloud at lass from the world meet logical organisation. it features newly classified cloud formations such as these as seen in dorset. and these dramatic undulating clouds pictured here in the peak district. still to come on weather world: michael, you have some history there. temperature tradition, more than 200 years of weather observing in ireland. i will go back to the

beginning and see how it is still being done today. we have had a look at modern aviation here at belfast international airport. but now i am stepping back in time to learn a little bit more about the history and the relationship between aviation and the weather. i have a personal reason for being here today. we will look at that later on. for now, let's head inside and meet our guide ernie from the ulster aviation society. hi there, ernie. hi, sarah, it's a pleasure to welcome you. before the introduction of satellite and radar data, aircraft played a vital role in forecasting. can you tell us more about that. yes, indeed, what it involved was the aircraft of the weather flights going out over the atlantic primarily from where most of our weather systems come, and taking a range of observations and different altitudes, observations of temperature, humidity, pressure and so on. it would have involved in some cases

flights of up to eight or nine hours in length. every so often the data that was being collected would be signalled back to aldergrove. and from aldergrove it would be sent to the forecasting office. why don't i introduce you to malcolm, a colleague who was a met observer on the weather squadron at aldergrove in the post—war period. that would be fantastic. malcolm, you were met observer on those weather flights. what was it like? a very interesting period in my life doing national service in the air force. we initially had very old aircraft, the halifax, we used to be directed by the weather forecasts, we would fly for a day into weather worst weather wasn't find out what was really happening. as we tended to fly the majority of the flights fairly low down it

could be very bumpy, very wet at the front because the aircraft used to leak a bit, being old. you could have lightning and it was a very difficult exercise for pilots and navigators to get there and back. with the poor radio waves and everything we would often be a bit of truck. it was arduous for the whole crew. i mentioned earlier that i had a personal link to this place. my grandfather was an aeronautical engineer in northern ireland for many years. can you tell me more about that? i really wanted to show you this aircraft, the short sherpa, a unique aircraft. it was built in 1953 to test the properties of a novel type of wing your grandfather designed. archive: the revolutionary new aircraft goes for its trials. the chief designer, david keith lucas, planned the sherpa on his drawing board and no test pilot tom brook smith looks set to continue.

we are delighted it is part of the ulster aviation collection because it is a unique research aircraft and your grandfather was responsible for that. thank you so much for showing me this little bit of my family history. for now we will be leaving these historic aircraft, later we're heading back to belfast international airport for more on modern day aviation. now to events in southern hemisphere summer and this from peru. if ever you need proof of the force of flood water it is here. look how the driver of this truck manages to get outjust it is swept away. and again as this hotel collapses into a flooded river. dozens of people had died in peru since the start of the year. here is another lucky escape as a mudslide churns up the debris of what was once someone's home, a woman emerges. slowly she is able to find her feet and step to safety.

the rain has been blamed on an unusually warm sea water off the coast of peru, but notjust peru has suffered. disaster in colombia, torrential rains is a mudslide into town, submerging homes, businesses and people. the death toll reaches into the hundreds. some in the area have blamed climate change for the extreme rain, others say deforestation means are more likely. further south in chile in january, drought, he took, strong winds and then fire. this town was destroyed by wildfires said to be the worst in the modern history of the country. thousands of homes are burned to the ground. summer fires also broke out in australia, nearly 100 at one stage in february in new south wales as record high temperatures produce catastrophic fire danger. in march the weather took a dramatic turn as cyclone debbie hit queens queensland and then new south wales.

floods follow and after its hottest summer, sydney has its wettest margin 20 years. —— march. viewed from helicopter, something quite astonishing is unfolding california in february. car swallowing sinkholes are appearing. there goes another. it is notjust cars disappearing, the ground is literally giving way as the state undergoes a remarkable transformation from drought with a succession of storms and weather bombs bringing flooding rain. there is so much water that the overflow from this town —— dam is needed for the first time in 50 years but it fails, leading to evacuation with fears of unrestrained floodwater being sent downstream. in a world of changing climate and weather, some things change very little. like this weather ritual which has been happening for over 200 years. at 9am every day, shane kelly takes

weather observations at the armagh observatory a0 miles south—west of belfast. his work and that of those before him has made this one of the longest—running series of manual weather observations in the world. shane, you have been doing this for 18 years and the temperature records goes back over 200 years. do you feel the weight of responsibility of keeping this going? it has been unbroken for 200 years, i don't want to be the one who breaks that are bad becomes infamous. it is a unique empirical record, it is a very useful record in research, schools, education for the general public. lots of weather stations are automated, what is the benefit of having you doing this every day? we had an automatic weather stations several years an experimental one.

it broke down, sometimes you lost records. we did not lose any on the manual side. on the automatic station you were sometimes recording wind speeds of a17 mph, you can see how an automatic station can get it wrong. do you think of the day when this might become automatic and you will not be required to do this any more? i think it will become automatic but i think the manual station will run side by side as long as there is a will for people to get up in the morning and take readings and do it every morning and keep the unbroken record. these are those first records, safely stored at the observatory. its director michael burton is about to show me how it all began. you have some history? i certainly have, these are the first readings

from the armagh observatory. let's look at that first one. we have the logbook and we have this page at the top, these were the very first measurements made. it has held up quite well? indeed. what is it telling us? the date, the first measurement is the 27th of december 179a. we are measuring the temperature inside and outside, two thermometers, one inside the observatory and one outside in the grounds, and the barometer, the air pressure. things get more detailed over time? notes are made about significant weather event. if we can call the 19th—century the more recent past, what happened there? 1839, the time of bromley robertson, the director here for 59 years. he is recording notes, the comment says a tremendous gale in the night. there was a fantastic storm that night, it got

robertson thinking about how one quantifies the strength of the wind and a few years later he came up with the design of what we call the anemometer, which is now use the world over to measure the wind speed. one of his first models this year? on the roof of the observatory building, you can go and see it. i have an amateur weather station on my back garden and it has this on it, and to think it all started here in armagh? this is the cap anemometer, it comes from 1870 but the very basic design is how we measure wind speed the world over. it say something about design that it has lasted the test of time? a simple design, four club spinning in the —— cups. wind, you can measure the wind speed and that is how we know wind speeds around the world. it has been fascinating seeing the weather history at the armagh observatory, thank you for showing us around. we are back at belfast

international airport, so far we have looks at how weather is pivotal to operations here and had seen some of the systems in place to deal with changeable weather conditions. i will put some about into practice and with the help of michael we will use the traffic control simulator to try to safely land a plane. imagine it is a foggy day at belfast, we have two inbound easyjets, one to the north we will factor them and establish them at ten miles, once they are safely established under the instrument landing system we can transfer and we —— can pretend we are transferring them to the tower. easy for 64, descent altitude 3000 feet. —— easy 464, descend to altitude 3,000 feet. we record the level on the strip and we watch the radar. you can see the aircraft is starting to descend. it looks like this aircraft has

safely intercepted the instrument landing system and it is on the approach to the runway? the aircraft is now approaching two miles from touchdown, he has been safely established. it is probably on a full auto land because it would be in fog and the pilots will be letting the aircraft land. that was really well done as a first attempt at vectoring and aircraft. it descended at nine miles, that is what we expected. well done. a very good first attempt. my first aircraft, safely landed. fantastic. now from a busy skies to roads, and these iconic london cabs are far from where you would normally expect to see them. this is the arctic circle, they are being tested as they get a 21st—century makeover with a virtually silent electric engine cutting emissions. it has been awhile since london has seen snow like this but the manufacturers hope to sell the cabs

in other polluted cities like moscow, which gets a bit colder in winter. finally, we have had automobiles, planes and now trains. this is what happens when you are waiting at a station after a snowstorm but the first train is nonstop. in march, new york commuters get a second helping of snow, but this one was not in the forecast! that is it for weather world this time from northern ireland. we will be back later in the year. until then, keep checking the forecast. let's look at that first reading. where did i put it?! we have lost the first reading from 1794. from now onwards the first readings will be from 1795. what is going on with my hair? what is it doing? it's peacocky.

she is so polite, isn't she?! any changes for easter in the forecast? no, pretty chilly. a lot of cloud, sunny spells and also some rain. currently it's raining heavily across parts of northern wales, any way, this is the forecast for the easter weekend. look at the winds, they're coming in from the north. all through the course of easter, more or less. that means it's going to remain on the chilly side. the air is coming from the arctic. this is the short—term or here and now. this thicker cloud is stuck across northern wales, producing quite a bit of rain. i think many of us will get a few bits and pieces of rain through the course of this evening. then overnight, that weather front is across the south of the country. perhaps a few spots here. then for

many of us, the second half of the night, early hours of saturday morning looking dry with clear spells and chilly. temperatures in the north around three or four degrees. in the south, eight to nine degrees. in the south, eight to nine degrees. tomorrow actually, not a bad day overall. there will be a fair bit of sunshine around of the the clouds —— around. the clouds build through the day. the south enjoying the best of the weather, southern half of the uk. sunshine around the coasts also inland too. you can see a bit of cloud around. then the further north you go, the cooler tgs. we've got —— cooler it is. maybe showers in northern ireland and into cumbria, western parts of scotland and actually, cold enough across the scottish hills for a little bit of sleet or snow, just tells you how cold that air is that's coming from the north. the rest of saturday, very little change. should be dry for most of us. some clear spells on the way saturday night into sunday. now this is easter day, so sunday, easter day. a bit of a headache forecasting

where this weather front will be. it could be further north, a little bit to the north, could be a bit more rain or less rain. the idea is that central portions of the uk and then probably east anglia and the south—east later on in the day will catch some light rain at least, whereas the further south west you are, the better the weather will be. easter monday, a bright day for most of us, with some showers affecting eastern areas. but overall, for most of us, easter monday is looking pretty dry. so, to summarise over the next few days, just take a brolly, just in case, if you're p°ppin9 brolly, just in case, if you're popping out for most of the day. today at five: the us defends its decision to drop a huge bomb on islamic state militants in afghanistan. 36 militants are thought to have been killed by the weapon — the most powerful non—nuclear bomb ever used by the us in combat. this was the right weapon against the right target. we will not relent in our mission to fight alongside our afghan

comrades to destroy isis in 2017. we'll be examining whether this marks a new front in the war on so—called islamic state. the other main stories on bbc news at 5... a british tourist in her 20s has been stabbed to death on a crowded tram injerusalem. the mission to re—take mosul. we've a special report from the front line. schools in england are facing their worst funding cuts in 20 years, a warning from teaching unions.