Precipitation
Precipitation--Any form of moisture that ______________ from the sky
The main forms are:
1.
2.
3.
4.
Rain
 __________________ precipitation
 Varies in size
 Normal raindrops between 0.5 to 5 mm
 Less that 0.5 mm ___________________
Snow
 May be
 Small _____________
 Individual s or
_____________________________
 Crystals that combine to form
_________________________
 Snowflakes are _____________at temps near 0 C and become smaller at
________________ temperatures
Sleet
 When snow falls through a _________________of freezing air
__________________ the surface
Damaging Precipitation
Hail
 Solid precipitation in lumps of ____________
 Spherical or lumps
 Forms in __________________________ clouds
Remember Convection!!!!
 Hot, less dense air _______________
 Requires ________________ ________________
 Patches of ___________________ help
Formation of Hail
Hail Formation
 Hail stones form by ______________
 Small hail gets caught up in the
_______________ and goes to the top of the
cloud where it receives another
______________ of ice
 This repeats until the hail ___________ be
___________________ by the updraft
and it falls
Hail requires _________________ updrafts to form
 For the smallest hail to form, an updraft of around 36 to 54 km/h (24-34 mph)
is required.
 golf-ball size (1 3/4 inch diameter) -- require updrafts of around 88 km/h (55
mph) to form.
 Softball-size hail involves updrafts exceeding 160 km/h (100 mph).
Hail Sizes
 Pea6.4 millimeters (0.25 in)
 Dime17.9 millimeters (0.70 in)
 Penny19 millimeters (0.75 in)
 Nickel21.2 millimeters (0.83 in)
 Quarter24.26 millimeters (0.955 in)
 Half dollar30.6 millimeters (1.20 in)
 Walnut38 millimeters (1.5 in)
 Golfball44 millimeters (1.7 in)
 Tennis Ball64 millimeters (2.5 in)
 Baseball70 millimeters (2.8 in)
 Grapefruit108 millimeters (4.3 in)
 Softball114 millimeters (4.5 in)
If you are going to take a hail picture show something in the picture to give a
sense of _____________________
Record hail fell in _________________________________, KS
Measuring Precipitation
 A Rain gauge is used to measure _______________________precipitation
Doppler Radar
 Doppler radar is a key _______________________________ tool
 Based on the _______________ _________________ also used with
___________________ and ____________________________
All weather radars send out radio waves from an antenna.
Objects in the air, such as raindrops, snow crystals, hailstones or even insects
and dust, scatter or ___________________ some of the radio waves back to
the antenna.
 All weather radars, including Doppler, electronically convert the reflected radio
waves into pictures showing the location and intensity of precipitation.
Remember the meteorologist saying
the wind is blowing ___________ or
_________________ from the radar
 Used to indicate
________________________ in a
thunderstorm which could indicate
a tornado forming