WEATHER FORECASTING

1. Bolivarian Republic of Venezuela
Ministry of Popular Power for Education
U.E "GENERAL EZEQUIEL ZAMORA”
8vo Grado Sección “B”
San Félix - Bolívar State
Teacher:
Francis Villarroel
Student:
Oscarina Duerto
Guayana City 15/04/2015

2. INTRODUCTION
Imagine an experiment with dozens of dependent variables and no controlled
variables. That's a good way to think about a weather forecast. The sun, the source
of all energy on Earth, would be the independent variable, well, sort of. Even
though the sun rises and sets on a steady schedule, and sends out fairly steady
amounts of energy, the Earth keeps turning below it! This causes differential
heating, so the air temperature is constantly changing. Clouds drift in and out of the
scene, and different concentrations of gases affect the weather "experiment". And
don't forget about air pressure, which changes with space and time too.
Forecasting weather is one of the hardest and most complicated things scientists
do on a daily basis. Meteorologists use many tools to tackle the job of weather
forecasting. Many start by looking at images provided by weather satellites. A
single satellite image holds tons of information. A meteorologist looking at this
image could tell where the mild air is, where the cold and warm fronts are, and
even identify stormy weather.

3. WEATHER FORECASTING:
For thousands of years, people have used countless methods to forecast the
weather. Some of the these methods are not very accurate. For example, if cows
sit down, it will rain. If the sky is red in the evening, it wil be hot next day. And if
cats sit with their backs to a fire, it will snow.
Today, we use technology to forecast the weather. Satellites orbit the Earth and
send information about the weather to all parts of the world. You can find weather
forecasts on television, on the internet and on cell phones.
Scientists say that, in the future, they will make the weather change as people
want. We will never be cold or wet again.
Weather forecasting is the application of science and technology to predict the
state of the atmosphere for a given location. Human beings have attempted to
predict the weather informally for millennia, and formally since the nineteenth
century. Weather forecasts are made by collecting quantitative data about the
current state of the atmosphere at a given place and using scientific understanding
of atmospheric processes to project how the atmosphere will change.
Once an all-human endeavor based mainly upon changes in barometric pressure,
current weather conditions, and sky condition, weather forecasting now relies on
computer-based models that take many atmospheric factors into account. Human
input is still required to pick the best possible forecast model to base the forecast
upon, which involves pattern recognition skills, teleconnections, knowledge of
model performance, and knowledge of model biases. The chaotic nature of the
atmosphere, the massive computational power required to solve the equations that
describe the atmosphere, error involved in measuring the initial conditions, and an
incomplete understanding of atmospheric processes mean that forecasts become

4. less accurate as the difference in current time and the time for which the forecast is
being made (the range of the forecast) increases. The use of ensembles and
model consensus help narrow the error and pick the most likely outcome.
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. Temperature forecasts are used by utility
companies to estimate demand over coming days. On an everyday basis, people
use weather forecasts to determine what to wear on a given day. Since outdoor
activities are severely curtailed by heavy rain, snow and the wind chill, forecasts
can be used to plan activities around these events, and to plan ahead and survive
them.
Ancient forecasting
For millennia people have tried to forecast the weather. In 650 BC, the Babylonians
predicted the weather from cloud patterns as well as astrology. In about 340 BC,
Aristotle described weather patterns in Meteorologica. Later, Theophrastus
compiled a book on weather forecasting, called the Book of Signs. Chinese
weather prediction lore extends at least as far back as 300 BC, which was also
around the same time ancient Indian astronomers developed weather-prediction
methods. In 904 AD, Ibn Wahshiyya's Nabatean Agriculture discussed the weather
forecasting of atmospheric changes and signs from the planetary astral alterations;
signs of rain based on observation of the lunar phases; and weather forecasts
based on the movement of winds.
Ancient weather forecasting methods usually relied on observed patterns of
events, also termed pattern recognition. For example, it might be observed that if
the sunset was particularly red, the following day often brought fair weather. This
experience accumulated over the generations to produce weather lore. However,

5. not all of these predictions prove reliable, and many of them have since been found
not to stand up to rigorous statistical testing
Modern methods
The Royal Charter sank in an 1859 storm, stimulating the establishment of modern
weather forecasting.
It was not until the invention of the electric telegraph in 1835 that the modern age
of weather forecasting began. Before that, the fastest that distant weather reports
could travel was around 100 miles per day (160 km/d), but was more typically 40–
75 miles per day (60–120 km/day) (whether by land or by sea). By the late 1840s,
the telegraph allowed reports of weather conditions from a wide area to be
received almost instantaneously, allowing forecasts to be made from knowledge of
weather conditions further upwind.
NEW MOON:
New Moon is the second movie based on the famous series of books written by
Stephenie Meyer, iwilight in new moon, the incredible love story between Bella and
Edward ends up.
Bella spends more time with her friend jake and all change.
Like in the first movie, the locations were fantastic, specially the scenes filmed in
the forest. The characters clothes and the soundtracks were cool, too we’re looking
forward tto seeing next movie.
commonly referred to as New Moon, is a 2009 American romantic fantasy film
based on Stephenie Meyer's 2006 novel New Moon. It is the second film in The
Twilight Saga film series and is the sequel to 2008's Twilight. Summit
Entertainment greenlit the sequel in late November 2008, following the early
success of Twilight. Directed by Chris Weitz, the film stars Kristen Stewart, Robert
Pattinson, and Taylor Lautner, reprising their roles as Bella Swan, Edward Cullen,

6. and Jacob Black, respectively. Melissa Rosenberg, who handed in a draft of the
film script during the opening weekend of Twilight, returned as screenwriter for
New Moon as well.
Filming began in Vancouver in late March 2009,[5][6][7] and in Montepulciano, Italy
in late May 2009. The film was released on November 20, 2009 in most countries,
and set domestic box office records as the biggest midnight screening, grossing
$26.3 million, which was superseded by its sequel, The Twilight Saga: Eclipse.
This led to the highest single day, domestic gross on an opening day, with $72.7
million, until it was beaten in 2011 by Harry Potter and the Deathly Hallows – Part
2, which made $91.1 million, by nearly $20 million. Furthermore, New Moon
opened with the third highest domestic opening weekend since 2002 grossing a
total of $142,839,137. The film also became the highest grossing film released by
Summit Entertainment, and was the widest independent release, playing in over
4,100 theaters in its theatrical run, until it was surpassed by The Twilight Saga:
Eclipse.
New Moon was released on DVD and Blu-ray Disc on March 20, 2010 through
midnight release parties. As of July 2012, $184,916,451 in North American DVD
sales, selling more than 8,835,501 units, 4 million of which were sold within its first
weekend, beating Twilight's 3.8 million units sold in its first two days. The film was
well received by fans, but received mixed to negative reviews from critics.

7. FINDING
Weather forecasting has come a very long way since the Babylonians and the
Greeks started observing the skies, and it was the pioneering work of Vilhelm
Bjerknes and Lewis Fry Richardson at the beginning of the 20th century that kicked
off the development of modern weather forecasting. But without the invention and
subsequent improvement of computers, numerical weather prediction would still be
in its infancy. Understanding chaos and developing new and better weather
observation methods also contributed to improving forecast accuracy. A six-day
forecast nowadays is now as accurate as a one-day forecast in 1968 Current one-
day forecasts are accurate in 9 out of 10 cases, and three-day forecasts still have a
hit rate of 70%. Current research suggests that these percentages will continue to
increase in future. Apart from normal weather forecasts, weather services also
issue specialised forecasts for a variety of domains, such as agriculture, aviation
and shipping, which help save lives and money. Still, meteorologists at the
ECMWF estimate that the global economic loss due to inaccurate weather
forecasts amounts to up to a billion Euros per year so meteorologists hope that
improved forecast quality will reduce this number.
The two different types of forecasting models, one of them based on finite
differences, the other one based on the spectral method, are currently competing
as to which one of them yields more accurate forecasts for a given computational
cost. But at the end of the day, each model has its strengths and weaknesses; so
using both models side by side will probably give the best results.
In the future, weather forecasts will be even more accurate and more detailed than
forecasts nowadays. And who knows, maybe one day mathematicians will find a
way to overcome the two weeks forecasting limit, so that long-range forecasts can
be produced.

8. BIBLIOGRAPHY
https://cimss.ssec.wisc.edu/satmet/modules
www.wikipedia.com

9. ANEXO