Lesson 5: Simple techniques for weather forecasting

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Module 6 Weather Forecasting
Virtual Academy for the Semi Arid Tropics
Modules
Lessons

Lesson 5 Simple techniques for weather
forecasting

• After completing this Lesson, you have learned
  to answer
• What simple techniques for predicting weather are
  available?
• How sight is used for predicting weather?
• How do you predict weather by cloud watching?
• How to predict temperature and rainfall using
  your sense of touch?
  

Course on Crop-Weather Relationships
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Module 6 Weather Forecasting
Virtual Academy for the Semi Arid Tropics
Modules
Lessons

Lesson 5 Simple techniques for weather
forecasting

• How do you predict weather by wind watching?
• How your sense of hearing help in weather
  forecasting?
• How farmers predict weather by observing some
  natural phenomena?
• How farmers perceive weather by the behavior of
  certain birds and animals?
• What cultural and social beliefs are used by some
  farmers to know about incoming weather?

Course on Crop-Weather Relationships
3
Lesson 5 Simple techniques for weather
forecasting

• Are there any simple techniques for predicting
• weather?
• Previously when there was not much of
  technology developed for weather forecasting,
  farmers based their prediction on many natural,
  cultural and social phenomena.
• Some of these techniques are discussed in this
  Lesson.

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Lesson 5 Simple techniques for weather
forecasting

• Are there any simple techniques for predicting
  weather?
• Yes. You can observe weather using your senses
  
• Sight,
• Touch,
• Hearing, and
• Smell.

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Lesson 5 Simple techniques for weather
forecasting

• How sight is used for predicting weather?
• Sight is the easiest sense to use when you
  forecast. You use sight when you watch clouds to
  forecast the weather.
• Go outside and look up at the clouds. Clouds
  can tell you many things about what the
  weather will do. 

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Lesson 5 Simple techniques for weather
forecasting

• Sight
• Thin and wispy clouds found very high in the sky
  point the direction the wind is blowing.
• No precipitation falls from such clouds. They are
  a sign of fair weather for now and the very near
  future. 

Fair weather clouds
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Lesson 5 Simple techniques for weather
forecasting

• Sight
• Clouds, which are like fuzzy bubbles in long rows
  or strings usually, mean that a cold front is
  coming.
• If it is summertime, warm and humid these clouds
  may turn into thunderstorms.

Possible rain- clouds
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Lesson 5 Simple techniques for weather
forecasting

• Sight
• Dark and low-hanging clouds covering the whole
  sky bring light to moderate rainfall.

Rain giving clouds
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Lesson 5 Simple techniques for weather
forecasting

• Sight
• Clouds looking like big cotton balls in the sky
  with very large spaces of clear sky in between
  them normally do not carry any rain.
• But, during summer these clouds can change into
  thunderstorm clouds.

May rain clouds
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Lesson 5 Simple techniques for weather
forecasting

• Sight
• Tall and wide clouds have heavy rain, thunder and
  lightning.
• If you see these clouds on the horizon, it is
  likely it will rain very soon.

Heavy rain clouds
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Lesson 5 Simple techniques for weather
forecasting

• Touch is another sense that can be used when
  forecasting temperature and rainfall.
• For example
• You can feel the sun hitting your face which
  indicates the air temperature is high.
• You can feel your face get colder when it is
  raining in the nearby area. Combining with
  cloud watching you can forecast how soon you can
  expect rain in your area.
• You use touch when you use the wind to forecast
  the weather, like in wind forecasting. 

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Lesson 5 Simple techniques for weather
forecasting

• Touch
• Forecasting the temperature sensing the wind is
  simple.
• But it only works if the wind is strong enough to
  feel it.
• A very light breeze won't tell you much about the
  temperature. 

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Lesson 5 Simple techniques for weather
forecasting

• Touch
• First, know which direction is north from where
  you are standing.
• When you find north, turn and face that
  direction. The direction behind you will be
  south.
• If the wind is coming from the south, usually it
  means that warmer weather is on its way soon.
• If the wind is from the north, usually it means
  that cooler and dryer weather is on the way.
• East or west moving winds can mean a variety of
  things, which makes it difficult to forecast
  using them.

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Lesson 5 Simple techniques for weather
forecasting

• Hearing
• Hearing is useful for forecasting the weather.
• When you hear thunder, you know that a storm is
  nearby, even if you didn't see the lightning.
• You can hear the wind blow harder or softer
  through trees or as it whips around your ears.

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Lesson 5 Simple techniques for weather
forecasting

• Are there any other simple techniques for
  predicting weather?
• Based on certain natural phenomena farmers
  used to predict weather.
• If the spectrum around the sun had a greater
  diameter than that around the moon, they
  predicted rainfall after a day or two.

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Lesson 5 Simple techniques for weather
forecasting

• Are there any other simple techniques for
  predicting weather?
• Based on certain natural phenomena farmers
  used to predict weather.
• If there is an accumulation of clouds in
  the south-east direction in a layered form
  accompanied by winds blowing from the
  southern direction then it is claimed that
  there will be rainfall within a day or two.

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Lesson 5 Simple techniques for weather
forecasting

• Are there any other simple techniques for
  predicting weather?
• Weather prediction was also perceived by some
  farmers based on certain birds and animals.
• If the Maina bird bathes in the water it
  indicates that there will be rainfall within
  one or two days.

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Lesson 5 Simple techniques for weather
forecasting

• Are there any other simple techniques for
  predicting weather?
• Weather prediction was also perceived by some
  farmers based on certain birds and animals.
• A group of sparrows playing on the sand
  indicates that there will be rainfall that day
  or the next day. But, if they are observed to
  be playing in water then it is believed that
  the weather will be dry for some days to come.

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Lesson 5 Simple techniques for weather
forecasting

• If the "Tatihari" bird (Lapwing) lays her eggs on
  the higher portion of the field then heavy
  rainfall is predicted during the coming rainy
  season.
• But if the eggs are laid in the lower portion of
  the field then a drought is predicted. These
  birds never construct a nest but lay their eggs
  on bare soil.

Lapwing bird
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Lesson 5 Simple techniques for weather
forecasting

• If dragon flies, which appears generally in the
  rainy season, are observed to swarm in a large
  group over a water surface (pond) then dry
  weather is predicted.
• But if they swarm over open dry lands or fields
  then early rainfall is predicted by the farmers.
• If centipedes emerge from their holes carrying
  their eggs in swarms in order to shift them to
  safer places, then farmers predict early
  rainfall. The centipedes do this so as to avoid
  egg damage which can be caused by rain water.

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Lesson 5 Simple techniques for weather
forecasting

• When spider nets are plentiful on grasses, sticks
  of tomato crop and on French bean crop then it is
  estimated that the rainy season is over.
• If there is a swelling on the lower portion of
  the camel's legs then rainfall is predicted by
  the farmers. The swellings are probably caused
  due to higher relative humidity.

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Lesson 5 Simple techniques for weather
forecasting

• Social and cultural beliefs
• Many cultural, social and religious beliefs and
  activities superstitious pertaining to the
  prediction of future weather prevail since
  generations.
• From time immemorial farmers have predicted the
  weather on the basis of these beliefs and
  activities.
• A few examples follow.

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Lesson 5 Simple techniques for weather
forecasting

• Social and cultural beliefs
• If summer months (March to May) are very hot, a
  good monsoon rains are expected.
• It is believed that it will rain before and after
  Diwali festival.

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Lesson 5 Simple techniques for weather
forecasting

• Social and cultural beliefs
• The winter in South India comes to an end from
  Shivaratri festival onwards.
• During the rainy season, if a cloud appears on
  Friday and Saturday then rainfall is predicted
  either for Sunday or Monday as believed by the
  farmers in Himalayan region.

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Module 6 Weather Forecasting
Virtual Academy for the Semi Arid Tropics
Modules
Lessons
Exercise

This concludes Lesson 5 Simple techniques for
weather forecasting - in this Module. If you
would like to check your understanding about
weather forecasting, click Exercise button. In
the next Module is briefly about interpretation
of weather for farm operations. Click Modules
button to select Module 7
Course on Crop-Weather Relationships