Weather forecasting

Weather forecasting is the application of science and technology to predict the state of the atmosphere for a given location. Weather forecasts are made by collecting quantitative data about the current state of the atmosphere at a given place and using a scientific understanding of the atmospheric processes to project how the atmosphere will change. There are a variety of end uses to weather forecasts. Weather warnings are important forecasts because they are used to protect life and property. Forecasts based on temperature and precipitation are important to agriculture, and therefore to traders within commodity markets.

The weather is one of the most powerful important forces on the earth but do we know what the weather is going to be like so we can plan ahead. A lot can go wrong if we don’t plan for the weather while we are busy with our everyday life a global network of gadgets scan and measure the atmosphere, collecting data from all over the world. For example, radar systems, weather balloons, Ocean monitoring boys and lots of other cool instruments track changes to help predict the weather. Another vital ingredient is space way out in orbit weather satellites are getting the big picture of atmospheric changes.

These European where the satellites met up and meteor sat give us the ability to see the weather before it reaches us. Orbiting the Earth 14 times a day around 850 kilometers our meta keeps a close eye on the temperature, humidity, and winds. Metopes observations along with all the other data are fed into powerful supercomputers. These huge machines then crunch their way through millions of bits of data about current weather oceans and the atmosphere to forecast future weather. The process is called numerical weather prediction and is what scientists use to help us plan our lives.

In a very short-range forecast, for example, the product called a 6-hours QPF or Quantitative Precipitation Forecast. it’s basically the amount of precipitation that’s expected to reach the surface within a 6-hour period. Also, issued by forecasters at the Weather Prediction Center.

In Short-range forecast, Short-range weather forecasts generally tend to lose accuracy as forecasters attempt to look farther ahead in time. Predictive skill is greatest for periods of about 12 hours and is still quite substantial for 48-hour predictions. An increasingly important group of short-range forecasts are economically motivated. Their reliability is determined in the marketplace by the economic gains they produce (or the losses they avert). For example, the product called 12-hour Probability of Precipitation forecast. Also, issued by forecasters at the Weather Prediction Center. Forecasts available at 12-hour time steps to include day 3 thorough day 7. The valid date-time stamp is the ending time of the 12-hour period.

Extended-range or long-range, weather forecasting has had a different history and a different approach from short- or medium-range forecasting. Instead, long-range forecasters have tended to use the climatological approach, often concerning themselves with the broad weather picture over a period of time rather than attempting to forecast day-to-day details. Most long-range forecasts thus attempt to predict the departures from normal conditions for a given month or season.

Q2:

A thunderstorm (also known as electrical storm, lightning storm) is a storm in which there is lightning and the accompanying acoustic effect of it, thunder (hence the name). Thunderstorms vary in terms of precipitation; while rain accompanies most thunderstorms, other options include hail, sleet, snow; a thunderstorm can also have no precipitation. Another usual companion of thunderstorms is strong wind, which also serves as one of the indicators in determining the severity of thunderstorms. If the wind speed measurements exceed 57,5 miles per hour, a thunderstorm is considered severe. There are two more markers of a severe thunderstorm: a tornado accompanying it, or one inch hail or greater. Severe thunderstorms can cause serious damage to the infrastructure; they cause flooding, strong destructive winds and tornadoes.

Thunderstorms occur daily on Earth, and about 10% of the annual number of thunderstorms that happen in the US are classified as severe thunderstorms, which means that there are about 10000 severe thunderstorms each year in the US only. Thunderstorms are more likely to happen in the afternoon or in the evening during spring and summer, however, this does not mean that they do not occur in different times and seasons. At any given moment, there are about 2000 active thunderstorms around the globe.

At the core of a thunderstorm’s formation is the process called convection. Convection is the upwards motion of the warm air in the atmosphere, which also carries the moisture from the surface along with it. The warm air and the moisture are the key components in forming cumulonimbus clouds, from which thunderstorms take their beginning. Cumulonimbus clouds are the results of the instability caused by the warm air from the surface bringing the moisture into the upper layers of atmosphere.

Thunderstorms begin forming with the sun warming up the air above the Earth’s surface. If there are favorable conditions for this warm air to rise (due to the hills or mountains in the area with the colder air around them), the warm air begins rising upwards, carrying the moisture from the Earth surface together with it. As the warm moist air reaches the height at which the water vapor begins to cool, the cumulonimbus cloud begins to form from the condensed vapor. This is the process of convection in action.

The cloud continues its upward motion into the layers of the atmosphere, where the temperature is below freezing. This causes different types of ice particles to form inside the cloud. Ice particles form by condensation from vapor, and then grow by collecting smaller liquid drops that are in the supercooled state (which means that they have not frozen yet). It is in these conditions where the electric charge for lightning begins to form. Ice particles collide with each other, and often times, it results into pieces of particles being broken off, and electric charge being transferred from one particle to another. On a large scale, these collisions form regions of electric charge that cause lightning bolts. There is another theory about how lightning is formed, which will be discussed in the answer to the second question.

Each thunderstorm goes through three phases: the developing stage, the maturing stage, and the dissipating stage.

During the developing stage a cumulus cloud rises up in the layers of the atmosphere, being carried by an updraft, until, eventually, the precipitation begins to fall out of the cloud, and the thunderstorm moves into the mature stage. During the mature stage, the updraft continues to feed the warm and moist air into the cloud, however, the precipitation forms a downdraft – a column of cold air headed towards the surface, creating gusts of wind near the surface. Eventually the downdraft overpowers the updraft, and the thunderstorm enters into a dissipating stage, during which the precipitation still continues to fall but the thunderstorm is not developing further because the column of the warm moist air that has been feeding it is no longer there to sustain the thunderstorm.

Q3:

Lightning is a natural phenomenon that occurs when two regions of opposite charge discharge, which results into an electrical spark between them. There are various types of lightning, as there are also different theories explaining its formation.

An inseparable attribute of lightning is thunder, which is the result of the air rapidly expanding due to the heat caused by the passing lightning bolt. At close distances, a loud cracking sound can be heard, which is the result of the charge traveling through what is called the stepped leader – a channel of negative charge flowing downwards from the cloud. After the initial crack, the ‘body’ of the thunder follows. At longer distances, only the low-end thunder rumble can be heard, because high frequencies are absorbed by air at a higher rate than low frequencies.

There are two theories about what causes lightning to form. The first one is called precipitation theory, and it posits that the areas of opposite electrical charge form due to the light precipitation particles colliding inside the cloud and losing or gaining some of the electric charge, while heavier particles carrying most of the negative charge to the lower end of the cloud.

The second theory is called convection theory. According to the convection theory,

the updrafts carry the positive charge from the ground together with the warm air and moisture, while the downdrafts carry negative charge from the cloud, and the lightning occurs where the two charges meet.

Depending on the path the lightning takes, there are three types of it: cloud-to-ground lightning, cloud-to-air lightning, and cloud-to-cloud lightning.

Cloud-to-ground lightning occurs when the channel of negatively charged particles called the stepped leader (because of the path it forms as it travels through air) heads down to the ground. As the stepped leader approaches the ground, it meets a positively charged channel called streamer, which usually happens to be some sort of a taller structure: a tree, a pole, a skyscraper, a mountain or a hill. When the two channels meet, a lightning travels upwards, back to the cloud at a speed as high as 60000 miles per hour.

Cloud-to-air lightning is when the lightning bolt does not travel down to the ground, and the electrical discharge happens within a cloud. This phenomenon is called sheet or intra-cloud lightning, because of the visual effect it produces: the cloud where the sheet lighting occurs appears to be a sheet of light dissipating through the cloud.

Finally, the cloud-to-cloud lightning is when the lighting bolt travels across the air from one cloud to another.

It has been recently discovered that lighting forms anti-matter particles in the terrestrial gamma-ray flashes that are associated with thunderstorms and lighting.

Electric fields that exist in the thunderstorms create a wave of electrons that move upwards; as the electrons move through air, they are being deflected by the air molecules, and that is when electrons begin emitting gamma-rays. The gamma-ray energy collides with the electrons, which accelerate near to the speed of light, and, when a gamma-ray passes near the nucleus of an atom, it transforms into an electron, and positron, which is an anti-particle. The electrons and positrons then escape the Earth’s atmosphere, where they can be detected by the spacecraft, such as, for example, Fermi gamma-ray space telescope.

            Discuss the nature of tornadoes and how it relates to the earth’s weather. Provide details on the formation, types and life cycle of tornadoes.  Also discuss the type of equipment and steps to observe and monitor tornadoes on the ground.

Tornadoes are the narrow columns of rapidly rotating air, which descend from the thunderstorm down to the ground. Tornadoes achieve visibility when they have carry water droplets, dust or debris inside, otherwise it might be difficult to spot a tornado because air movement is not visible to the naked eye.

Much like thunderstorms, tornadoes occur all over the world, with few regions being especially prone to having tornadoes form in them. Depending on the severity of a tornado, it is assigned a rank on a scale that includes measurements, such as the wind speed and the level of damage a tornado causes. The scale that is currently in use is called Enhanced Fujita Scale, which is an improved version of a scale that has been used before.

There is little information about the way tornadoes form. It is a known fact that the most destructive tornadoes form in the supercells, which is a type of a thunderstorm that rotates and has a very well-defined structure. There are theories about the tornado formation may be linked to the temperature differences in the air in a supercell but these theories need further work in order to develop working methods of explaining and predicting tornadoes.

Although the most destructive and dangerous tornadoes form in a supercell thunderstorms, they can occur in a non-supercell storms too.

When forming in a supercell, a tornado begins with the two layers of air moving at different speeds and/or directions at different heights. The difference in speed and direction between these two layers forms a rotating column of air, which is initially in a horizontal position. However, the warm and moist updraft has the capacity to tilt this column, so it eventually turns into a horizontal column of rotating air, and that is where the supercell tornadoes are believed to come from.

Non-supercell tornadoes are not fed by the rotation of the storm, because there is no rotation in a non-supercell thunderstorm. The non-supercell tornadoes form near the ground, where a vertical rotating column of air is already present. There are also other types of tornadoes, such as gustnadoes, land- and waterspouts. The first is rotating dust and debris that occur close to the ground on the gust front of the storm. Landspouts and waterspouts occur when a rotating column of air with condensation forms while the thunderstorm is still forming, so the rotation in this type of tornadoes originates near ground or water.

The methods used to observe tornadoes range from direct observation on the ground to analyzing radar data. Storm spotters are trained people who know a set of visual cues that are known to be associated with tornadoes, and they look for them in the forming or ongoing thunderstorms. These visual cues have to do with the shapes of the thunderstorm clouds and the anomalies in them. Other methods of observing tornadoes include analyzing Doppler radar data on thunderstorms for patterns that suggest the presence of an existing tornado, or looking for cues that might show areas where there are favorable conditions for a tornado to form. A lot is being done in terms of forecasting tornadoes and alerting the public about severe weather, and further research into the nature of tornadoes will enhance the forecasting tools which, in turn, will result into more accurate forecasts and earlier warnings for the population.

Q4

Tornadoes are among the deadliest storms on the earth associated with extreme weather conditions. The new studies also say that climate change will lead to more destructive tornadoes in future. They start from the oceans and take lots of moisture from there causing immense rainfall in the land region. The winds move very fast in an spiral manner and is funnel shaped. Sometimes the wind speed is so high that they can break trees and buildings as well.

They are formed during thunderstorms and cumulonimbus clouds. There should be change in wind direction and rising air that should be swirling. As soon as this funnel shaped wind touches the ground, it results into formation of tornado. They vary in size.

There can be following types of tornadoes – (a) Supercell – its life is more and is more violent (b) Waterspout – it is formed on water and dissipates when reaches the ground (c) Landspout – It is weak in nature (d) Gustnado – it is a small tornado (e) Multiple vortex tornado

The steps followed to identify a tornado are that NOAA is held responsible to issue warnings for tornado as ‘watches’ and ‘warnings’. watch means a tornado may result due to favorable weather conditions while warning means tornado is going to come soon and you have to take action immediately.

I hope the answer is up to your requirement, in case you need further help, please leave a comment we will try our best to fix it for you

Q5:

Thunderstorms are formed by vertical convection and development of charged regions within a cumulus cloud. The development of charges is because of collision of updrafting ice crystals and downdrafting ice pellets (Bergeron- Findesen Theory) or by Splintering process, i.e. when ice crystals are formed, H⁺ ions migrate towards the cooler rim and OH^– ion migrate towards the warmer core. On splintering of the ice crystal H⁺ ions are released thereby separating the positive and negative charges. The electrified cloud has vertical charge stratification of alternate positive and negatively charged layers.When charge difference increases the air gap between the land and the cloud is ionized and we see a lightning strike when the opposite charges meet.

The thunderstorm can be of single cell which lasts less than an hour. It can also be a multicell thunderstorm which occur in the leading edge of rain cooled air front. It involves hailstorms and sever rainfall. Stronger updraft is present due to combined effect of several convection cells. Each cell lasts for 30-60 minutes but the whole system lasts for several hours. Squall lines are several thunderstorms occurring in a linear fashion. They generally occur in the leading edge of a cold front.

Mesoscale convection system (MCS) is a larger feature may cover an entire state. It is a combination of several thunderstorms (single and multicells), squall lines, lake effect snow (cooler air is warmed by flowing over warmer lake,it picks up moisture and rise up) and Mesoscale convection complexes. The occur in a cold front, may be round or linear in shape extending for hundreds off kilometers. However they are smaller than extratropical cyclones.

MCS appear as monstrous features in radar showing a solid line or broken lines depending on its organisation. They can last more than 12 hours and involve severe rainfall, hailstorms and thunderstorms. After and MCS dissipates, it may leave behind some mesoscale convective vortexes. These vortexes are low pressure centers which attract circling air towards it. They may be 30-60 miles across and 1-2 miles deep. They may last for 12 hours after the MCS has dissipated. These vortexes can give rise to newer thunderstorms. If these Vortexes move into tropical waters like the Gulf of Mexico, they get the abundant moisture and may form the nucleus of tropical storms and hurricanes