Weather Words 2013

1. Meteorologist - A scientist who studies and predicts the weather

2. Atmosphere - A layer of gases surrounding the Earth. Contains mostly nitrogen and oxygen.  78% nitrogen and 21% oxygen.

3. Troposphere - ItŐs the lowest portion of Earth's atmosphere. Day to day weather occurs in the troposphere. ItŐs where we live

4. Air Pressure - The weight of the air pressing down on earth. ItŐs the same as barometric pressure.

5. Barometer - An instrument that measures air pressure.

6. Climate - the average weather conditions in a certain place over hundreds or thousands of years.

7. Clouds – are condensation.  Tiny water droplets.

8. Cirrus Clouds - Thin, wispy clouds that form high in the atmosphere as their water vapor freezes into ice crystals.

9. Cumulus Clouds - Fluffy, mid-level clouds that develop in towering shapes and signal fair weather. Cumulus clouds are a principle cloud type.

10. Stratus Clouds - Low-lying, gray and sheetlike clouds that often produce drizzle. One of the three main types of clouds.

11. Nimbus - The Latin word for "rain" used to describe a cloud or group of clouds from which rain is falling.

12. Cumulonimbus – Huge, summertime clouds that produce thunderstorms, super tall.

13. Condensation - The change of water vapor to liquid water, as when fog or dew forms.

14. Convection current – how heat is transferred through the atmosphere.

15. Dew Point - The temperature at which water starts to condense out of a particular air mass. Condensation happens at the dew point.

16. Fog - A cloud on the ground

17. Front - A boundary between two different air masses, resulting in stormy weather. A front usually is a line of separation between warm and cold air masses.

18. Warm Front - The boundary between two air masses, one cool and the other warm, moving so that the warmer air replaces the cooler air.

19. Low Pressure System - A whirling mass of warm, moist air that generally brings stormy weather with strong winds. Acts like a vacuum cleaner, causes a warm front

20. Cold Front - A boundary between two air masses, one cold and the other warm, moving so that the colder air replaces the warmer air.

21. High Pressure System - A mass of cool, dry air that generally brings fair weather and light winds. Acts like a bucket of water. Causes a cold front.

22. Occluded Front - A combination of two fronts that form when a cold front catches up and overtakes a warm front.

23. Stationary Front - A boundary between two air masses that more or less doesnŐt move

24. Water Vapor – evaporated water, is a gas, in the atmosphere.

25. Humidity - water vapor in the air.

26. Relative Humidity – amount of water vapor contained in the air compared to the maximum amount of moisture that the air can hold at a certain temperature. Described as 50% or 62% or whatever it is.

27. Absolute humidity-the total amount of water vapor that the air can hold, the air is full, and condensation will begin if the air cools at all.

28. Hygrometer - An instrument that measures the water vapor content of air or the humidity.

29. Jet Stream - A strong high level wind at about 6 to 9 miles above the ground, acts like a fence between cold arctic air and warm air. Brings our really cold winter air

30. Rain Gauge - An instrument used to measure the amount of rain that has fallen. Measurement is done in hundredths of inches (0.01").

31. Saffir-Simpson Scale - A hurricane intensity scale that relates hurricane damage to wind speeds and central air pressures.

Category 1: wind speeds 74-95 m.p.h.    Category 2: wind speeds 96-110 m.p.h.

Category 3: wind speeds 111-130 m.p.h.  Category 4: wind speeds 131-155 m.p.h.

Category 5: wind speeds over 155 m.p.h.

32. Sea Breeze - A breeze that blows from the sea to the land.  caused by the temperature difference when the surface of the land is warmer than the water

33. Severe Thunderstorm Warning – warns the public, when a severe thunderstorm is forecast to occur or is occurring.

34. Severe Thunderstorm Watch - issued when conditions are favorable for the development of severe thunderstorms.

35. Sun –the source of all energy on Earth, causes our weather.

36. Temperature - The measurement of how hot or cold something is.

37. Thermometer - The instrument that measures temperature.

38. Thunder - The explosive sound of air expanding as it is heated by lightning.

39. Thunderstorm - A storm produced by a cumulonimbus cloud and always has lightning and thunder. Rain, hail and high winds may or may not occur.

40. Tornado - starts as a funnel cloud with spinning columns of air that drop down from a severe thunderstorm. When they touch the ground they become tornadoes. Tornadoes are between 300 and 2,000 feet wide and travel at speeds of 20 to 45 miles per hour. They usually only last a few minutes, but their spinning winds, up to 300 miles per hour, can lift houses into the air and rip trees from the ground.

41. Funnel Cloud - A tornado that doesnŐt reach the ground.

42. Tornado Warning – issued when a tornado is forecast to occur or is occurring.

43. Tornado Watch - ItŐs issued when conditions are favorable for the development of tornadoes.

44. Tornado Alley – part the  of the United States where tornadoes  most happen. Tornado alley is between the Plains area from the Rocky Mountains on the west to the Appalachian Mountains on the east.

45. Fujita Scale - The scale that measures the strength of tornadoes based upon wind speed.

F0: winds 40-72 m.p.h. - (Light damage) Branches broken off trees

F1: winds 73-112 m.p.h. - (Moderate damage) Trees snapped and mobile home pushed off foundations

F2: winds 113-157 m.p.h. - (Considerable damage) Mobile homes demolished and trees uprooted

F3: winds 158-206 m.p.h. - (Severe damage) Trains overturned and cars lifted off the ground

F4: winds 207-260 m.p.h. - (Devastating damage) Houses leveled and cars thrown some distance

F5: winds 261-318 m.p.h. - (Incredible damage) Houses lifted and thrown some distance

46. Tropical Depression - ItŐs a low-pressure disturbance that forms over warm tropical ocean waters and produces winds of 38 m.p.h. or less. Can become a tropical storm.

47. Tropical Storm - ItŐs a low-pressure disturbance that forms over warm tropical ocean waters. In the United States, a tropical storm has winds between 39-73 m.p.h. can become a hurricane.

48. Hurricane - They are intense storms with swirling winds up to 150 miles per hour. Usually around 300 miles across, hurricanes are 1,000-5,000 times larger than tornadoes. Typhoons and cyclones are other names for hurricanes.

49. Weather - the condition of the air at a particular time and place, right now.

50. Wind – moving air, caused by differences in pressure.

51. Anemometer - A weather instrument that measures the wind speed.