HumidityThe amount of water vapor in the airTemperature affects how much moisture is in the air - warmer air can hold more water vapor, tending to make it more humidRelative humidity the amount of water vapor in the air compared to what it can hold at a specific temperatureWhen air cools, it cant hold as much water vapor, so the water vapor condenses to liquid or forms ice crystalsDew point the temperature at which air is saturated and condensation forms

CloudsForm when air rises, cools to its dew point, and becomes saturatedShape and height of clouds vary with temperature, pressure, and water vapor in atmosphere

CloudsShapeStratus-smooth, even sheets or layers at low altitudesCumulus-puffy, white clouds, often with flat basesCirrus-high, thin, white feathery clouds made of ice crystalsHeightCirro high cloudsAlto middle-elevation cloudsStrato low cloudsNimbus clouds are dark and so full of water that sunlight cant penetrate them

CloudsLOW CLOUDS form at 2,000 m or less in altitudeCumulus puffy clouds formed when air currents rise and carry moistureStratus layered dull, gray sheets that can cover the entire skyNimbostratus low, dark, thick layers that hide the Sun

Cumulus Clouds formed at medium or low elevation. Cumulus clouds are puffy with flat bottoms. When cumulus clouds are white they often signal fair weather, but when they are darker, they may signal rain or thunderstorms.

StratusClouds formed at medium or low elevation; spread out layer upon layer covering a large areaAs stratus clouds thicken, precipitation usually occurs over that area.

Cumulus

Stratus

CloudsMIDDLE CLOUDS form between 2,000 m and 8,000 m in altitudeMost are layeredNames have alto- prefix (altocumulus and altostratus)Can produce light precipitation

CloudsHIGH AND VERTICAL CLOUDS Cirrus wispy, high-level cloudsCirrostratus high, layered clouds that can cover the skyCumulonimbus known as thunderstorm clouds; produce heavy precipitation

CirrusClouds formed at high elevations; wispy clouds usually consisting of ice crystals that signal fair weather or may also signal an approaching warm front.

Cirrus

Cloud Cover Symbols You will often see the circles drawn on a weather map

Air MovementWind: Movement of air from one temperature or pressure area to anotherDifferent areas of Earth receive different amounts of the Suns energyEquators warm air, being less dense, is pushed upward by denser, colder airPoles cold air, being more dense, sinks and moves along Earths surfaceCORIOLIS EFFECT: spinning of the Earth causes moving air to turn to the right in the northern hemisphere and to the left in the southern hemisphere

Global WindsWind patterns, caused by convection currents combined with the Coriolis effect, of Earth that affect the worlds weatherNear equator, very little wind and daily rain patterns called the doldrumsSurface winds:Between equator and 30 degrees N and S latitude are steady trade windsBetween 30 and 60 degrees N and S latitude, the westerlies blow in opposite direction from the trade winds.The polar easterlies blow from northeast to southwest near the north pole and from southeast to northwest near the south pole

Global WindsEquatorial doldrumsTRADEWINDSTRADEWINDS

The Weather HighwaysThe rotation of the earth creates the Coriolis effect. The Coriolis effect causes the air and water to be deflected to the right (north of the equator).This creates global weather highways

FrontsBecause air and moisture move in the atmosphere, weather is constantly changingFronts are a boundary between two air masses of different density, moisture, or temperature. clouds, precipitation, and storms occur at frontal boundariesThere are four different air masses

The Air MassescP( continental polar) : cold, dry stablecT( continental tropical) : hot, dry, stable air aloft, unstable at the surfacemP( maritime polar) : cool, moist, unstablemT( maritime tropical) : warm, moist, unstable

This map shows the air mass source regions and there paths

Air Mass Map

Cold Front

Warm Front

Occluded Front

Stationary Front

Anemometer- A tool used to measurewind speed in miles per hour.Wind vane A tool used to measure wind direction. Sometimes referred to as awind-weather vane or a wind sock. Wind direction is described by the direction from which the wind is blowing.Thermometer - A tool used to measure air temperature in degrees Fahrenheit or Celsius.

Sling Psychrometer- A two-thermometer instrument also referred to as a wet-dry bulb used to measure relative humidity (the amount of water vapor in the air). Temperatures readings are converted using a relative humidity table.

Barometer- A tool used to measure air pressure in inches of mercury or millibars (mb).

Rain gauge- A tool used for measuring the amount of precipitation in inches or centimeters.

Reading a weather mapISOBAR= connects areas of equal pressure BAR comes from BARometric pressure

Reading a weather map...Isotherm: Connects areas of equal temperature; therm means temperature

Satellites Satellite images are used for seeing cloud patterns and movements. For example, hurricane clouds and movement can be observed using satellite images.Radar Radar images can be used to detect cloud cover, rainfall or storm location, intensity, and movement, as well as the potential for severe weather (for example, hurricanes or tornadoes).

Severe WeatherThunderstorms occur inside warm, moist air masses and at frontsWarm, moist air is forced rapidly upward, where it cools and condensesStrong updrafts of warm air and sinking, rain-cooled air cause strong winds

LightningMovement of air inside a storm cloud causes parts of the cloud to become oppositely chargedCurrent flows between the regions of opposite electrical charge, forming a lightning boltThunder lightning superheats the air, causing it to expand rapidly and then contract, forming sound waves

TornadoViolent, whirling wind that moves in a narrow path over land

HurricaneLarge, swirling, low-pressure system that forms over tropical oceansHeat energy from moist air is converted to wind that can reach speeds of 250 km/h

BlizzardA winter storm with strong winds, cold temperatures, and low visibility, that lasts more than three hours

Severe Weather SafetyA National Weather Service WATCH means conditions are favorable for severe weather to developA warning means that severe weather conditions already existMeteorologists study and predict weatherNational Weather Service makes weather maps and issues watches and warnings

Lets break for a short review1.Transfer of heat in liquids or gases:_____2. _____ air is dense and tends to sink.

4. Cold air holds _____ moisture than warm air5. The Coriolis effect causes the air and water to be deflected to the _____ (south of the equator)

How did you do?1. CONVECTION

2. COLD

3. ITCZ

4. LESS

5. LEFT