PRECIPITATION Flashcards
__________ are formed when raindrops are carries upward by ______________________ into extremely cold areas of the atmosphere and freeze.
hail, thunderstorm updrafts
_______ is a liquid precipitation falling from the sky. Rain occurs when air rises into the upper atmosphere and cools.
rain
______ is like a mix of “rain and snow”, it starts as a snowflake but melts into raindrops as it falls through a layer of warm air.
sleet
_______ is precipitation that forms when “water vapor freezes”. It is ice crystals that form in the cold clouds.
Snow
TYPES OF PRECIPITATION ( origin based)
_____________
rapid upward movement of warm air causes short, intense rainfall, often with thunderstorms or hail.
convective storms
TYPES OF PRECIPITATION ( origin based)
_________________________
moist air rises over mountains, leading to heavy rain on the windward side and drier conditions on the leeward side.
orographic storms
TYPES OF PRECIPITATION ( origin based)
_______________
Large low - pressure systems bring widespread, prolonged rainfall.
cyclonic storms
TYPES OF PRECIPITATION ( origin based)
___________________
intense storms over warm oceans produce heavy rain, strong winds, and storm surges
hurricanes or tropical cyclones
TYPES OF PRECIPITATION ( non - origin based)
liquid water drops
rain
TYPES OF PRECIPITATION ( non - origin based)
ice crystals
snow
TYPES OF PRECIPITATION ( non - origin based)
small ice pellets
sleets
TYPES OF PRECIPITATION ( non - origin based)
large ice balls
hail
TYPES OF PRECIPITATION ( non - origin based)
rain that turns to ice on surfaces
freezing rain
TYPES OF PRECIPITATION ( non - origin based)
soft ice balls formed on snowflakes
graupel
RAINFALL CHARACTERISTICS
How much water has fallen over a period of time
depth
RAINFALL CHARACTERISTICS
refers to the length of time rainfall occurs
duration
RAINFALL CHARACTERISTICS
ratio of the total amount of rain falling during a period of time
intensity
RAINFALL CHARACTERISTICS
graphical representation between rainfall intensity and time
hyetograophy
POINT RAINFALL MEASUREMENTS
also known as station rainfall
point rainfall
POINT RAINFALL MEASUREMENTS
Rainfall is expressed in terms of the _______ to which rainwater would stand on an area, if all the rain were collected on it.
depth
This is an instrument to measure “rainfall rate” in a certain period of time. It catches and represents the precipitation falling on a respective surrounding area.
rain gauge
2 types of rain gauge
non recording
recording
example of a non recording rain gauge
Symon’s Rain Gauge
Example of a recording rain gauge
weighing bucket type
tippingg bucket type
floating type
MISSING RAINFALL DATA ( Estimation)’
availability of continuous record of previous rainfall
continuity
MISSING RAINFALL DATA ( Estimation)’
_________________
rainfall data of previous year should be consistent with the present environmental condition
consistency
CONVERSION OF POINT RAINFALL to AERIAL RAINFALL
this method is calculated by taking an average of the values that are obtained from several observation points or stations within the region
arithmetical - mean method
CONVERSION OF POINT RAINFALL to AERIAL RAINFALL
This method assigns weightage to stations based on proximity, superior to the arithmetic mean method. It’s effective for outside catchment stations and easy to calculate for fixed networks
Thiessen - Mean Method
CONVERSION OF POINT RAINFALL to AERIAL RAINFALL
This entails drawing isohyets derived from precipitation data of different stations and then taking an average precipitation by integratong over the areas which correspond to these lines
isohyetal method
A test for consistency of record or for rain gauge inconsistency
Double Mass Analysis
