2. Observing & Recording the Weather
• Weather is the condition of the air around us
over a short period of time ex. Rainy or cloudy.
• Meteorology is the study of the atmospheric
conditions & air circulation.
A meteorologist is a person who studies the weather
& works at the meteorological (met) office.
The met station is the place where they forecast the
weather.
There are a number of instruments which help in the
forecast of the weather.
3. Weather & Measurements
Description of weather Measurements used
1. Temperature - how hot or 1. Thermometer (⁰C)
cold it is.
2. Precipitation - how water 2. Rain Gauge (mm)
from the air falls to the
ground.
3. Beaufort Scale (force)
3. Wind Speed – How strong
the wind is blowing.
4. Wind Direction – From 4. Wind Vane
where the wind is blowing
4. Weather & Measurements(cont)
5. Cloud Cover - The 5. Octa (Factors of eight)
amount of sky covered
by clouds.
6. Cloud type - this is 6. Cumulonimbus,
based on the shape, cumulus, stratus &
size & height of the cirrus
cloud.
7. Meters
7. Visibility - the distance
that can be seen.
8. General weather – 8.Sunny, rainy, cloudy, etc.
Description in words of
the weather.
7. Features affecting
Temperature & Wind
• Microclimate is the climate conditions of a
small area which is different from the general
surrounding.
• What causes Microclimate?
Physical features - Forest, Hills, Lakes & Seas
Shelter - Walls, Trees, Hedges, Buildings
Surfaces - The color of the ground surface
Buildings - Provide shade from sun & shelter from wind
Aspect – The direction in which a place is facing
8. Places facing the sun will be warmer
than those in the shadow
Hilltops are usually cool
and windy
Water areas such as lakes have
a cooling effect and my also
produce light winds
9. How does it rain?
The water cycle (hydrological cycle) begins by
Evaporation & Evapotranspiration (water
changes from liquid to gas). As the moist air rises
it cools & water droplets form. Then
condensation occurs & cloud forms. As the water
droplets grow larger they become too heavy &
fall to the ground - precipitation which usually
happens in the form of rain. Then the surface
runoff goes back to sea.
10.
11. Types of rainfall
• Frontal rainfall happens when a mass of warm
air meets a mass of cooler air.
• Warm air is lighter then cooler air & is forced
to rise.
12. Types of rainfall(cont)
• In Relief rainfall the warm moist air is forced
to rise over mountains.
• When the air rises, it cools, condensate & rain
falls.
13. Types of rainfall(cont)
• In Convectional rainfall the sun warms up the
ground, which warms up the air above it.
• The warm air rises, it cools, condensates &
rain falls.
14. Anticyclones
• Anticyclones are high pressure weather
system, which usually gives good weather.
• The air sinks, clouds do not form and
therefore no rain occurs.
• In summer, anticyclones bring hot and sunny
weather, whilst in winter they bring clear
skies, low temperatures with a risk of fog or
frost.
15.
16. Depressions
• Depressions are low pressure weather systems
that produce cloudy and rainy weather.
• Depressions develop when warm air meets
cold air and bring a sequence of weather
changes as they pass overhead.
• Due to the rising of air caused by the
movement of the fronts and interaction
between the warm and cold air there are lots
of clouds and precipitation.