Mrs. Passell’s Weather Test ReviewThe test will assess your understanding of clouds, precipitation, water cycle, fronts, high & low pressure areas, weather maps, weather instruments and storms.

It will not cover the layers of the atmosphere, air as a mixture, or heat transfer.

COMMON TYPES OF CLOUDS.

STRATUS CLOUDS Stratus clouds are not

individual “units’. These are the lowest

clouds. They produce

widespread rain or snow.

Fog is a stratus cloud close to the ground.

CUMULUS CLOUDS Puffy clouds like the ones you

drew in first grade Fair weather clouds

CUMULONIMBUS CLOUDS• Thunderheads• Bring heavy rains,

lightning, thunder• May bring violent

weather

http://www.crh.noaa.gov/images/ilx/swop/clouds.jpg

CIRRUS CLOUDS• High altitude, thin

clouds• Wispy, like feathers• Made of ice crystals• Sometimes called

“mare’s tails”

http://www.met.tamu.edu/class/Metr304/Severedir/CirrusClouds.jpg

FRONTSAn AIR MASS is the large body of air that has the characteristics of the land over which it develops. The whole air mass will have the same temperature, pressure and humidity.

A FRONT is the place where two air masses meet.

SYMBOLS FOR FRONTS

think of cold pointy icicles

think of the warm sun rising in the east

- not on the test

think of a stationary exercise bike - - you’re pedaling but not going anywhere!

MOVEMENT OF FRONTS

The front is moving in the direction of the points or half-circles. Stationary fronts are stationary so they are not moving!

WARM FRONTRemember that warm air is less dense than cold air so it will slide up over the more dense cold air.

WARM FRONT

The weather is rainy or snowy as the front approaches and the temperature starts to rise.

Warm Front. Image Credit: NOAA; http://tinyurl.com/c3o9gtu

COLD FRONT

A cold front pushes under the less dense warm air. Violent storms can occur.

STATIONARY FRONTThe WARM FRONT and COLD FRONT come together along a stationary front. The weather will be unsettled and for a few days.

WATER CYCLE/ HOW CLOUDS FORM.

PRECIPITATION : RAIN & SNOWRain – liquid water; most common form of precipitation

Snow - - Just like rain except it passes through layers of freezing air as it returns to Earth

PRECIPITATION : SLEET, HAIL & FREEZING RAIN

Sleet - - rain passes through cold air close to the groundHail - - ice crystals rise & fall within the thunder- cloud; when they become too large, they fall to EarthFreezing Rain – regular land that freezes when it lands on surfaces that are 32º or lower

ISOBARSThese lines connect places that have equal air pressure. The closer together the lines are, the stronger the winds will be.

HIGH PRESSURE AREAS

High pressure is indicated with an “H” The weather will be fair.

LOW PRESSURE AREASLow pressure systems are marked with an “L”. Cloudy weather & precipitation is found in low pressure areas. The center of all storms, including hurricanes, are low pressure areas.

WINDSAir moves from areas of high pressure to areas of low pressure.

HURRICANESThese storms form along the warm tropical waters near the equator.

http://spaceplace.nasa.gov/hurricanes/

HURRICANESIf you could slice into a tropical cyclone, it would look something like this. The small red arrows show warm, moist air rising from the ocean's surface, and forming clouds in bands around the eye. The blue arrows show how cool, dry air sinks in the eye and between the bands of clouds. The large red arrows show the rotation of the rising bands of clouds.(http://spaceplace.nasa.gov/hurricanes/)

TORNADOA tornado forms from a thunderstorm. Warm moist air meets cool dry air. Changes in wind speed and direction at different altitudes cause the spinning to begin.

DROUGHTDrought occurs when there is little or no precipitation for a long time.

http://en.wikipedia.org/wiki/2012–2013_North_American_drought

HOW LARGE BODIES OF WATER AFFECT WEATHER

Large bodies of water hold their heat longer than areas of land far from water.

WEATHER INSTRUMENT: ANEMOMETERmeasure the speed of the wind

WEATHER INSTRUMENT: BAROMETERmeasure air pressure in inches or mercury or millibars

WEATHER INSTRUMENT: HYGROMETER or PSYCHROMETER

measures the humidity (the amount of moisture in the air)

WEATHER INSTRUMENT: WEATHER VANE or WIND VANE

shows the direction the wind is blowing

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WEATHER INSTRUMENT: THERMOMETER

measure the temperature

WEATHER INSTRUMENT: RAIN GAUGEmeasure the amount of rainfall

?Adapted from >Mr. B. FontaineMrs. J. PhippsMrs. C. KoopParts of this powerpoint were kindly donated to www.worldofteaching.com

SOURCESTornado> http://www.weatherwizkids.com/weather-tornado.htm

Drought > http://en.wikipedia.org/wiki/File:Current-USDM.gifhigh to low pressure > http://hsc.csu.edu.au/primary_ind/prim_ind_240/compulsory/AHCWRK201A/3264/pressure_cells.htm