Bellwork 2/24Which equation expresses Newton’s second law of motion?A. F = maB. F = m __ aC. F = m − aD. F = m + a

Weather Forecasting

FrontsA boundary between 2 air masses of different

density, moisture, or temperatureRepresented on weather maps by various

types of curving linesCloudiness, precipitation and storms

sometimes occur at frontal boundaries

Types of fronts1. Cold fronts2. Warm fronts3. Occluded fronts4. Stationary fronts

Cold fronts – draw pictureShown on a map as a blue line with trianglesOccurs when colder air advances toward

warm airCold air wedges under warm air

Warm fronts – draw pictureShown on a map as a red line with

semicirclesOccurs when lighter, warmer air advances

over heavier, colder air

When cold and warm fronts meetWarm air is lifted, it cools and water vapor

condenses, forming cloudsWhen the temperature difference between

the cold and warm air is large or the cold front moves in quickly:Thunderstorms and even tornadoes may form

warm & cold fronts – draw pictures

Occluded frontsInvolves 3 air masses of different

temperatures:1. Colder air2. Cool air3. Warm air

May form when a cold air mass moves toward cool air with warm air between the two

The colder air forces the warm air upward, closing off the warm air from the surface

Shown on maps as purple lines with triangles and semicircles

Occluded fronts- draw picture

Stationary frontsOccurs when a boundary between air masses

stops advancingMay remain in the same place for several

daysProducing light wind and precipitationShown on maps as an alternating red and

blue lineRed semicircles point toward the cold airBlue triangles point toward the warm air

Stationary fronts – draw picture

Why does weather change?Air massesAir pressureFronts

Severe Weather

Thunderstorms Heavy rain falls, lightning flashes, thunder

roars, and hail might fallOccur in warm, moist air masses and along

frontsOccur when warm air is lifted rapidly as

cooler air sinks

Tornadoes A violently rotating column of air in contact

with the groundOccur along fronts when cold fronts rapidly

approach warm fronts

Hurricanes Read pages 610 – 611Answer questions 3a and 3b

Extra InformationA barometer is used to measure barometric

pressureMaritime refers to waterContinental refers to landThe National Weather Service (NWS) is

responsible for tracking hurricanesSatellite imagery has significantly improved

in the last 20 years to help us have a better understanding of hurricanes

The warmest part of a hurricane is the eye of the storm

Bellwork 2/25Scientists are studying the use of vegetable oil as an automotive fuel.Which of these is a logical justification for continuing this research?A. The research may also help scientists develop new vegetables for use as food.B. Vegetable oil can be purchased at grocery stores, so there would be less need for fueling stations.C. Using vegetable oil will increase the number of cars that can be used byincreasing the available fuel for cars.D. The fossil fuel used to make gasoline is becoming a limited resource, while vegetable oil is made of plants crops that are renewable.

Classwork 2/25Complete weather forecasting worksheetTurn in when finished.If you do not finish in class, it is homework.If you finish before the bell rings, read a book

or work on something from another class.

Bellwork 2/26Power grids use alternating current (AC) in transmission and distribution systems. Which statement explains why AC is used instead of direct current (DC)?F. Transmission wires cannot carry enough direct current to supply the needs of the power grid.G. The voltage can be changed in an alternating current system to transferenergy more efficiently.H. Electrical energy must be transmitted as alternating current because that is how it is produced at power plants.J. Direct current would not be useful to electric company customers because appliances operate on alternating current.

Classwork 2/26You will work with a partner to complete the

Coriolis worksheet.If you finish before we start to go over it,

read a book or Scholastic magazine.