tWC Editor, Dr Catherine Muller, was recently interviewed for a special edition newspaper which will be handed out in the Ted Baker Store in Heathrow Terminal 3 to mark the launch of their new weather-themed store decor. Here’s what she had to say:
Q. Can you tell us a little about you, your position at the Royal Meteorological Society, and how you got there?
My role as Head of Public Engagement at the Royal Meteorological Society (RMetS) involves engaging members and the wider public on matters of weather and climate, as well as communicating news about the Society via a range of projects and initiatives. This includes online news features for theWeather Club, external publications, social media, membership development, marketing, communication and other outreach activities – so it is a very diverse roll.
My interest in weather and climate was sparked at a young age; I was obsessed with the weather, and each night I would watch the end of every news bulletin eagerly awaiting the weather forecast. (This was usually to find out whether a heatwave or blizzard was on its way, depending on the season!) Clearly this early interest had a big impact and at the age of 10 I had already decided I would like to be a TV weather presenter. Although that particular career path didn’t transpire, from that moment onwards my future in meteorology was paved. Many years later I went on to receive an MSc in Applied Meteorology and Climatology and a PhD in Atmospheric Science from the University of Birmingham. I then worked as a Research Fellow in the Earth Observation Science group at the University of Leicester, and then returned to Birmingham to work on a project establishing weather stations in schools across Birmingham to study the climate of the city. Both positions involved substantial research, teaching, educational outreach, public engagement and science communication activities – so my experiences naturally led me to my current role at RMetS.
Q. How easy is it to predict heatwaves and Indian summers?
Heatwaves are periods of prolonged hot, and often humid, weather, relative to normal conditions. They affect large areas, persist for days or even weeks and often bring uncomfortable daytime and nighttime conditions. They are caused by a slow-moving high pressure system and occur in the UK due to the location of the jet stream which is usually north of the UK in the summer, allowing high pressure and persistent, settled weather to develop. These systems are referred to as ‘blocking highs’ as their presence makes it more difficult for other weather systems to move across an area, resulting in extended hot, dry, sunny weather. Forecasters can identify the weather patterns that may result in a heatwave several days in advance, making them a little easier to predict than unsettled weather. The Met Office has a Heat Health Watch warning system that issues alerts – levels 1 to 4 – if a heatwave is imminent.
‘Indian summer’ is the term used to describe a warm, calm spell of weather in autumn after a spell of cold weather or a good hard frost. It is thought to originate from Native American Indians who could use such conditions to continue hunting. Our ability to forecast them is the same as for any heatwave or period of warm weather, and there is no statistical evidence to suggest that Indian summers occur at particular times. Localised, long range forecasts (beyond 5 days into the future) are difficult due to the chaotic nature of the atmosphere. However extended-range forecasts up to 30 days into the future can provide some indication of how the weather might change or vary from normal (i.e. warmer, colder, wetter, drier) but only across the UK as a whole.
Q. What’s the best way to deal with extremes of temperature, both hot & cold?
There are many things you can do to stay comfortable during heatwaves, including having a cool (but not cold) shower, wearing loose, light clothes, hats and sunglasses, staying out of the sun during 11am and 3pm (remember that sun cream!), opening windows and shutting curtains during the day, and of course, it is essential to stay hydrated, so drink plenty of water! I’d also recommend freezing some damp flannels or a bottle of water for cooling down when it becomes oppressive. It’s also very important to check up on elderly and vulnerable people who may be less able to cope in the heat. If you live in a town or city, escape to the countryside for a break if you can, as cities tend to be warmer, particularly at night. Indeed, keeping cool at night is key during a heatwave.
Conversely, during extremely cold weather it is important to stay ‘wrapped up’ when you venture outside, layers are key, as well as socks, hats, gloves and scarves. Grit any driveways, steps or surfaces that could become icy. Rather than turning your central heating system up too high, warm clothing and blankets are a cosy way to help you to stay warm indoors. If you can, plan ahead and insulate any outside water pipes to prevent them freezing. I always keep a supply of de-icer to hand, as well as foil covers for the car. Local travel advice is now provided routinely, and should be considered before heading out.
Q. What type of weather results in the best sunsets?
A little lesson in physics is needed here! Sunlight is made up of a spectrum of colours ranging from red to violet - the colours of the rainbow - with each having a slightly different wavelength. Air molecules scatter sunlight as it travels through the atmosphere, in particular the shorter wavelengths - the blue and violet light - which is why the sky appears blue to us. When the sun is lower in the sky, such as at sunset, the light must pass through more of the atmosphere and much more scattering of the blue light occurs, which is deflected away in different directions before reaching us. This means that more of the longer wavelengths - the red and orange light - reaches us at the surface. But in order for the sky to appear a really vivid red or orange, high-level clouds such as cirrus, which are made up of ice crystals, are often present as they scatter and reflect the red light making the sky appear as though it is on fire. Other clouds (such as mid-level altocumulus) can also provide a pretty sunset if the conditions are right. In which case, a decaying daytime shower around sunset with associated high cloud often provide a beautiful sunset.
Dust and pollution in the upper atmosphere - such as that from a volcanic eruption - can also give us beautiful sunsets. In fact, the skies in Turner’s paintings are linked to volcanic eruptions. However, ground level dust and haze do not have the same effect, but rather they subdue twilight colours – if they did, cities like London would regularly have amazing sunsets! So low-level clean air is also an important factor.
Q. How true is the ‘red sky in the morning, shepherd’s warning’ adage?
It is true, to a degree. Following on from above, and for the same reason, orange and red skies can also be seen at sunrise. The presence of a red sky in the morning or at night can be associated with the onset or passing of certain weather systems. This is behind the saying, ‘Red sky at night, shepherd’s delight. Red sky in the morning, shepherd’s warning’, which was indeed used by shepherds to help predict the weather.
The saying does bear some truth, particularly in the UK where weather systems generally move in from the west. A red sky in the morning can imply that the sun, which rises in the east, is illuminating clouds in the western sky, indicating that a weather system and poor weather is on its way. Whereas, since the sun sets in the west, a red sky at night means that the setting sun is shining its glow on departing clouds, implying that the storm has passed, and that it’s likely to be another couple of days before the next storm reaches us. However, this isn’t always correct: not all weather systems travel west to east in the UK, or in other countries. And more importantly, simply because one weather system has passed, it doesn’t mean that another one isn’t following close behind!
Q. Why is a prolonged period of sun often followed by a massive shower in the UK?
Heatwaves and prolonged periods of very hot weather often culminate in storms, due to the build-up of heat and humidity – though it isn’t actually as common in the UK compared to the tropics, where heat is always followed by rain. Summer storms develop when the warm air rises, cools and the water vapour in the air condenses into cloud droplets. Under the right conditions, this occurs rapidly, forming large cumulonimbus clouds and ultimately rain showers, thunder and lightning - another of my favourites! It often feels ‘fresher’ after these storms.
Q. We’ve heard that if the cows are sitting down in a field, then it’s about to pour down. Is there a surefire way to know that it’s about to rain?
The theory behind the old wives’ tale which states that ‘if all cows are sitting down then there is a storm on the way’ is thought to have a number of origins; from the theory that cows can sense increasing air moisture, therefore head to the driest patch of grass to lie down and reserve it, to the idea that their stomachs are sensitive to changes in atmospheric pressure which occur as a storm approaches (meaning they lie down to ease it). However, these are just speculations and no one has actually proven that cows do in fact lie down prior to a storm - they may just happen to be tired, so not the best predictor of rainfall! However, even experienced forecasters sometimes struggle to know precisely where it is about to rain – especially for certain types of rainfall, such as thunderstorms, which can be extremely localised. So, even if the sky turns an angrier shade of grey in the distance, you cannot be certain that the storm will pass overhead – it may simply be the neighbouring town that receives the downpour. On the other hand, frontal rainfall - which occurs when warm and cold air masses meet - is much easier to predict, and accounts for most of the UK’s rainfall. There are lots of weather apps and websites which provide animated radar maps of rainfall, as well as the projected movement of the rain into the future, at short intervals (i.e. 15 minutes) – for example, RainToday or Met Office, but there are other sites too. These can be very useful for estimating whether the rainfall is heading your way, and a tool I use all the time. Try them out and impress your friends and family when you inform them it’s about to rain!
Q. Where would you choose for a weekend break in the UK if you wanted to avoid rain?
In general, places in the south and east of the UK tend to be sunnier, drier, warmer and less windy than those further north and west, so your best bet would be to head south-east for a weekend break. On average, the driest place in the UK is the village of St Osyth, between the Isle of Sheppey and Clacton-on-Sea in Essex, which has 502mm of rainfall each year – from reports I’ve heard it sounds delightful and has a beach nearby so I may now add it to my list! The sunniest place in the UK is Eastborne in East Sussex which has the record for the most hours of sunshine recorded in a month – another one to add to the list! Although, it really depends on the time of year, as these areas also experience summer thunderstorms – so if you want to avoid these, head towards Newcastle or even north Scotland!
Q. What’s the easiest thing to you check in the morning to see if you need to take an umbrella and/or sunglasses?
I would suggest checking the TV weather forecast or your favourite weather app or website alongside your breakfast (make sure you use well-known weather forecast providers though, as some are better than others). Most apps and websites have a breakdown of the expected weather through the course of the day for your local area, along with likelihood of rainfall occurring. This should allow you to prepare appropriately for the day – however, some people would argue that it’s worth keeping an umbrella close to hand at all times in the UK!
Q. How reliable is the weather forecast on TV nowadays, and how has that changed over the years?
Some national TV weather presenters are trained meteorologists - they obtain their information from weather forecasting companies and communicate this information to the public. Today, the 3-day weather forecast for the UK is as good as the 1-day forecast was 20 years ago – so they are certainly improving! This is mainly due to more powerful computers, a better understanding of the physics of the atmosphere and therefore improved forecasting models which simulates the atmosphere. However, forecasts will never be 100% perfect, as the atmosphere is chaotic and our models aren’t perfect - there is a saying that if a butterfly flaps its wings on one side of the globe, it leads to a hurricane on the other side of the globe several weeks later – this is known as the butterfly effect, and emphasises just how complex, chaotic and sensitive the atmosphere is. A 5-day forecast is now fairly reliable, unlike a 2 week forecast. Another change we are now starting to see in some of our forecasts is that the likelihood or probability is also given. (For example, 25% chance of rain would indicate that although the weather is expected to be mostly dry, there is still a small chance that rain may occur).
Q. How do you see climate change affecting the British weather in the future – will it be getting hotter as the earth warms up, or will we be subject to more extremes of temperature?
Average temperatures are continuing to rise globally and in the UK, largely due to emissions of greenhouse gases from human activities - and this will have various impacts on local weather in different seasons. It is difficult to predict exactly what will happen in specific locations, but for London (and many other parts of the UK), this could mean more frequent, intense and persistent summer heatwaves which could lead to increased risk of droughts and impacts on infrastructure and health. It may also lead to very wet winters with more intense downpours and a greater risk of flooding. Along with risks from sea-level rise this could put homes, businesses and service at greater risk, particularly along the Thames estuary. However it doesn’t mean that we will escape severe winter weather completely due to natural variability and the action of large-scale atmospheric systems that influence our weather.