Weather

A. Humidity

1. amt. of water vapor in air.2. Warm air can hold more water vapor than

cool air.3. Relative Humidity- percentage of water

vapor that is actually in the air compared to the maximum amt. of water vapor the air can hold at a particular temp.

4. 100% is said to be saturated (completely full)

B. Fog

1. Stratus clouds that form at or near the ground.

2. When ground cools at night after a warm, humid day, the ground cools the air above it to the air’s dew pt. The air condenses on the ground (condensation).

C. Hail

1. Round pellets of ice larger than 5mm.2. Forms inside cumulonimbus clouds during storms.3. Strong updrafts carry the hailstone up through the cold

region many times.4. Each time hailstone goes through cold region, a new

layer of ice forms around it. 5. Hail will become heavy enough to fall to the ground.6. Causes damage to crops, bldgs, and vehicles.7. P:\earth science videos\Hail and Updrafts.asf8. P:\earth science videos\Hail.asf

Teach your neighbor how hail forms.

II. Storms

A. Thunderstorms- forms in cumulonimbus clouds.B. Warm air is forced up along a cold front. As the air rises,

it cools and heavy rain or hail falls.C. Lightning- electric discharge, charges jump btwn parts

of a cloud, cloud to cloud, or cloud to ground.D. Lightning bolts heat air near it much hotter than the

sun’s surface.E. Rapidly heated air expands suddenly & explosively.F. Thunder is the sound of the explosion. G. Light travels faster than sound so you see lightning 1st.

Lightning distance

• Only do this inside a bldg.• Count the number of seconds until you hear thunder. If

you have a watch with a second hand or a digital watch that has seconds, begin timing as soon as you see the lightning and stop as soon as you hear the thunder start. If you don’t have a watch, do your best to count the seconds accurately. Say "One one thousand, two one thousand etc." in your mind for each second.

• Divide the number of seconds by 5 to calculate the distance in miles

Flood

• Floods can provide rich soil for farming.• When in a storm, avoid electrical appliances,

water, telephones and trees or poles. If lightening strikes these, it will strike you.

• Cars are safe b/c the lightning will hit the car and move around the metal around the car and go into the ground.

B. Tornadoes

1. rapidly whirling, funnel-shaped cloud that reaches down from a storm cloud to touch Earth’s surface.

2. If it occurs over water, it is a waterspout.3. How tornadoes form:

a. in cumulonimbus cloudsb. spring and early summer c. late afternoon

How tornadoes form (cont.)

4. Warm, humid air mass moves north from the Gulf of Mexico into lower Great Plains.

5. Cold, dry air mass moves south from Canada.6. When the masses meet, cold air moves under

the warm air, forcing it to rise.

7. Warm, moist air moves in at the bottom of the cloud and moves up. A low pressure forms inside the cloud.

8. Warm air begins to rotate as it meets winds blowing in different directions at different altitudes.

9. Best place to be is in a storm shelter or basement.

10. p. 453

• www.brainpop.com tornadoes• Login: lmscatoosa pw:warriors

• Teach your neighbor how tornadoes form.

Snowstorms

• Snowstorms occur when the entire atmosphere is O° C or colder and precipitation falls.

• Find shelter during snowstorms.

C. Hurricanes

1. Tropical cyclone that has winds of 119 km/hr or more.

2. In western pacific, they are called typhoons.3. Forms over warm ocean water as a low-

pressure area.4. It gets its energy from warm, humid air at the

ocean’s surface.

Hurricanes (cont)

5. warm, humid air rises and forms clouds and more air is drawn into the system.

6. Inside storm, very high winds and heavy rains.7. Winds spiral in toward the area of lowest

pressure at the center.8. The lower the air pressure, the faster the

winds blow toward the center.

Hurricanes (cont)

9. Winds are strong in the narrow band around the center of storm.

10. At the center, is a ring of clouds, called the eyewall, that enclose the quiet “eye”.

11. Wind gets stronger as eye approaches. 12.When eye arrives, weather changes suddenly

and is calm and clear sky.13. after the eye passes, storm resumes.

14. A storm surge is a dome of water that sweeps across the coast where the hurricane lands.

15. After hurricane passes over land, it no longer has warm, moist air to draw energy from and loses strength and dies.

Watches vs. Warnings

1. Watch- weather is conducive to having a tornado or flood. Haven’t had one yet. We are watching out in case we see one.

2. Warning- They HAVE SEEN a tornado or flood. Take cover if tornado.

\\Lmsadms2\vol1\PERSONAL\hmoorman\earth science videos\Hurricanes__Tornadoes__and_Other_Weather_nathural_phoenomena.asfHow Hurricanes Form

• Teach your neighbor how hurricanes form and what gives them their energy.

• \\Lmsadms2\vol1\PERSONAL\hmoorman\earth science videos\Hurricanes__Tornadoes__and_Thunderstorms.asf

• \\Lmsadms2\vol1\PERSONAL\hmoorman\earth science videos\Storms.asf

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On a separate sheet of paper, write: 3 things you learned about tornadoes

2 things you learned about hurricanes

1 thing you learned about hail