MET 200 MET 200 Introduction to Introduction to Meteorology Meteorology

Dr. R. Suseela Reddy

Weather and Climate

A Satellite’s View of the Weather Storms of All Sizes A Look at a Weather Map Weather and Climate in Our Lives Special topic: Meteorology: A Brief

History

Weather Elements

Temperature

Air Pressure

Humidity

Clouds

Precipitation

Visibility

Wind

Weather Elements Air Temperature – the degree of hotness or coldness

of the air. Air pressure – the force of the air above an area. Humidity – a measure of the amount of water vapor in

the air. Clouds – a visible mass of tiny water droplets and/or

ice crystals that are above the earth’s surface. Precipitation – any form of water, either liquid or

solid (rain or snow), that falls from clouds and reaches the ground.

Visibility – the greatest distance on can see. Wind – the horizontal movement of air.

Key Terms

Weather: The condition of the atmosphere at any particular time and place.

Weather Elements: The elements of air temperature, air pressure, humidity, clouds, precipitation, visibility, and wind that determine the present state of the atmosphere, the weather.

Climate: The accumulation of daily and seasonal weather events over a long period of time.

A Satellite’s View of the Weather

Geostationary Satellite – A satellite that orbits the earth at the same rate that the earth rotates and thus remains over a fixed place above the equator 36,000 km (22,300 mi).

Polar Orbiting Satellite – A satellite whose orbit closely parallels the earth’s meridian lines and thus crosses the polar regions(800 km) on each orbit.

A Satellite’s View of the Weather

Meridians – The dotted lines running from pole to pole on a satellite picture.

Longitude – depicts how far east or west, in degrees, it is from the prime meridian.

Parallels of latitude – The dotted lines that parallel the equator.

Satellite’s View of the Weather

        GOES East Hurricane SECTOR Visible Image

                                                                                                                                                                    

                     Hurricane Tracking Sector (VIS)

View Movie of the Visible Sector

Brought to you by the National Oceanic and Atmospheric Administration (NOAA)

Key Terms

Meridian: A great circle of the earth passing through the poles and any given point on the earth’s surface.

Longitude: The angular distance east or west on the earth’s surface from the Prime Meridian(zero meridian).

Latitude: The angular distance north or south from the equator of a point on the earths surface, measured on the meridian of the point.

Parallels of latitude: The dotted lines that parallel the equator.

Middle latitudes: The region of the world typically described as being between 30° and 50° latitude.

Storms of All Sizes

Mid-Latitude Cyclonic Storm (Extratropical Cyclone): A cyclonic storm that most often forms along a front in middle and high latitudes. (also called a depression or a low).

Hurricane: A severe tropical cyclone having winds in excess of 64 knots (74 miles per hour).

Thunderstorm: A local storm produced by cumulonimbus clouds. Always accompanied by lightning and thunder.

Tornado: An intense, rotating column of air that protrudes from a cumulonimbus cloud in the shape of a funnel or a rope whose circulation is present on the ground.

Surface Weather Map

A Look at a Weather Map

Surface weather map

Regional Surface Map

JSU Meteorology Program Weather Observations

Date 6/06/05Observer’s Name Monesa WattsTime of Observation 10:02a.m.

Yesterday’s High Temperature 92 FThis Morning’s Low Temperature 67 FTotal rain/snow last 24 hours 1.06 in

Current Temperature 72.1 F/ 22.3 CCurrent Sky Conditions BKN 040 (7/8 Sc)Weather RA

Wet-Bulb Temperature 70.1 FRelative Humidity (%) 92 %Dewpoint Temperature 67.0 F/19.4 C

Current Pressure 30.12 inPressure Tendency Rising (Code 0)Wind Direction & Speed VAR @ 5 MPH

Special or Additional Remarks/Comments:

METAR CODED OBSERVATION:

SPECI KJSU 061502Z VRB04KT 9SM RA BKN 040 22/19 A3012 RMK SLP 200 70106 8/5// T02230194 50xxx

Key Terms

Wind: Air in motion relative to the earth’s surface.

Wind Direction: The direction from which the wind is blowing.

Front: The transition zone between two distinct air masses.

Meteorology: The study of the atmosphere and atmospheric phenomena as well as the atmosphere’s interaction with the earth’s surface, oceans, and life in general.

Cumulonimbus Clouds

reaching high into the atmosphere Cumulonimbus clouds (Cb) are much larger and more vertically developed than

fair weather cumulus. They can exist as individual towers or form a line of towers called a quall line. Fueled by vigorous convective updrafts (sometimes in excess 50 knots), the

tops of cumulonimbus clouds can easily reach 39,000 feet (12,000 meters) or higher.

                                                 

     

Lower levels of cumulonimbus clouds consist mostly of water droplets while at higher elevations, where temperatures are well below 0 degrees Celsius, ice crystals dominate. Under favorable atmospheric conditions, harmless fair weather cumulus clouds can quickly develop into large cumulonimbus clouds associated with powerful thunderstorms known as supercells.

                                                 

      Photograph by: Knupp

Supercells are large thunderstorms with deep rotating updrafts and can have a lifetime of several hours. Supercells can produce frequent lightning, large hail, damaging winds, and tornadoes.

                                     

           These storms tend to

develop during the afternoon and early evening

when the effects of heating by the sun are strongest. For more

information about supercells and other types of severe weather

phenomena, visit the Severe Storm Spotters Guide.

Weather and Climate in Our Lives

Weather often dictates the type of clothing we wear, while climate influences the type of clothing we buy.

Climate determines what crop to plant and when. Weather affects how we feel(ex. Arthritis pain is most

likely to occur when rising humidity is accompanied by falling pressure.

Headaches are common on days when we are forced to squint due to hazy skies or a thin, bright overcast layer of high clouds.

Heavy fog can restrict visibility at airports, causing flight delays and cancellations.

Key Terms

Wind Chill Factor: The cooling effect of any combination of temperature and wind, expressed as the loss of body heat (effects tells us its much colder than it really is).

Chinook Wind: A warm dry wind on the eastern side of the Rocky Mountains (some people often become irritable and depressed).

Severe Thunderstorm: An intense thunderstorm capable of producing heavy showers, flash floods, hail, strong and gusty surface winds, and tornadoes.

Flash Flood: A flood that rises and falls quite rapidly with little or no advance warning, usually as the result of intense rainfall over a relatively small area.

Downburst: A severe localized downdraft that can be experienced beneath a severe thunderstorm.

Wind shear: The rate of change of wind speed or wind direction over a given distance.

NOTES On a hot, humid day we normally feel uncomfortably

warm and blame it on the humidity. If our bodies overheat, heat exhaustion or heat stroke may result.

Each summer scorching heat waves take many lives. Each year, the violent side of weather influences the lives

of millions. Tornadoes have not only taken many lives, but annually cause damage to building and property totaling in the hundreds of millions of dollars, as a single tornado can level and entire section of a town.

On the average, more people die in the United States from floods and flash floods than from any other natural disaster.

About the NWS

Weather Forecast/Professional Organizations

TV Broadcast Meteorologist(I.e. Weather Channel, Local News)

National Weather Service NOAA Weather Radio Website(UCAR, University websites-

weather.jsums.edu) American Meteorological Society National Weather Association

Working Together Keeps Weather Hazards from Becoming Weather Disasters

Make Sure Your School/Home/Office Has anAll-Hazards NOAA Weather Radio

NWS Services

Thank YOU!!