Weather

1. Weather

2. What is weather? • Refers to the state of the atmosphere at a specific time and place. • The one thing that you can talk to anybody about, it affects all aspects of life • If you don’t like the weather just wait around it will change • What are some of the factors that affect the weather?

3. Air Temperature • Temperature is the measure of the average amount of motion in particles.

4. Wind a natural movement of air of any velocity; especially: the earth's air or the gas surrounding a planet in natural motion horizontally

5. Humidity • The amount of water vapor present in the air • Relative Humidity -is a measure of the amount of water vapor present in the air compared to the amount needed for saturation at a specific temperature

6. Clouds • Masses of small water droplets or tiny ice crystals that float in the air. • Three main types are cirrus, cumulus, and stratus. • Other clouds are a mixture of these three main types.

7. Cloud Formation

8. Types of Cloudsbased on Shape and Altitude MAIN SHAPES • Cirrus • Cumulus • Stratus THREE ALTITUDE Groups • Low Clouds • Middle Clouds -start with prefix “Alto” • High Clouds - start with prefix “Cirro”

9. Cirrus • Cirro- means “curled” or “feathery” • Form highest in the sky; are made up of ice crystals; and appear as curls, tufts, or wisps. • Usually signal the end of clear weather. • High level clouds 18,000 to 30,000 ft.

10. Cumulus • Cumulo- means “heaped” or “piled” • Cottony clouds with flat, usually gray bases, and puffy, bright tops. • Usually signal good weather, but if atmosphere is unstable, can build into towering clouds that produce showers and thunderstorms. • Low level cloud 1,000 to 18,000 ft.

11. Stratus • Strato- means “layer-like” or “sheet-like.” • Low-lying, dull-colored clouds that form in layers or sheets. • Usually bring drizzling rain or light-falling snow.

12. Alto • A prefix meaning “middle range of clouds “ and used to describe clouds that lie from 6,500-18,500 ft. (1,980-5,640m).

13. Precipitation Clouds • Nimbostratus – rain, sleet, and snow • Stratus - drizzle, light rain • Cumulonimbus - rain, snow, sleet and hail • Altostratus – light rain (rarely)

15. High Cloud Types Cirrocumulus Cirrostratus Condensation Trails Cirrus Cirrus

16. Middle Cloud Types Altostratus Altocumulus

17. Low Cloud Types Cumulus Stratus Nimbostratus Stratocumulus Nimbostratus

18. Cumulonimbus

19. Precipitation • Water that falls from the clouds • Air temperature determines the form of precipitation that falls • 4 main types of Precipitation: Rain, Sleet, Snow and Hail

20. Types ofPrecipitation Rain Sleet Snow Hail

21. Air Masses • A large body of air that has properties similar to the part of the Earth’s surface over which it develops.

22. Types of Air mass source regions- Maritime (m) – forms over water and is moist (wet) Continental (c) - forms over land and is (dry) Polar (P) – forms over polar- regions and is (cold) Tropical (T) – forms in tropical regions and is (warm) Arctic (A) – forms over the poles and (very cold) Air masses that effect the U.S. Continental Polar (cP) – cold dry air Maritime Polar (mP) – moist cold air Maritime Tropical (mT) – moist warm air Continental Tropical (cT) – dry hot air Continental Arctic (cA) – dry very cold air

23. Air Mass Map

24. Fronts • A boundary between two air masses of different density, moisture, or temperature.

25. Types of Fronts

26. Cold Front

27. Warm Front

28. Occluded Front

29. Stationary Front

31. Severe Weather Thunderstorms Lightning Tornadoes

32. More Severe Weather Hurricanes Blizzards

33. Severe Weather Safety • Watches- conditions are favorable for formation of severe weather • Warnings- severe weather has formed and has been observed by a sighting or by RADAR • Examples of Severe Weather Warnings- Tornadoes, Flash Flooding, Severe Thunderstorms, Blizzards, Wintery Mix (snow and ice), High Winds, Tropical Storms and Hurricanes

34. THUNDERSTORMS • Form only in Cumulonimbus clouds • Can produce rain, snow, hail, Lightening, thunder, high winds and tornadoes • Forms individually by convection or multiple storms along a frontal system • Super cell thunderstorms exceed 40,000 ft.

35. Thunderstorm formation

36. Lightning 20,000 ft +. 32ᵒc 10,000 ft.

37. TORNADOES • Form only in Cumulonimbus clouds • Average life span 5-15 minutes Super cell tornadoes may last up to two hours • Small scale storms average 100 yards across, Largest recorded 2 miles wide 2013 in OK. • Wind speeds 65 to 300 mph • Forms over land- if formed over water it is called a Waterspout and is generally weaker

38. Tornadoes

40. Tornado Alley

41. Fujiti Scale

42. HURRICANES • Forms over warm tropical water • Large scale storms average 300 miles in diameter Largest typhoon Tip 1,800 mi. dia. • Wind speeds 75-200 mph • Losses strength when moves over land and warm moist air is cut off from oceans • Generally moves east to west with deflection to the right due to Coriolis effect • Average life span of 10 days • Longest was Hurricane Ginger 31 days

43. Hurricanes

44. Hurricane cross section Eye Outflow Spiral rain bands Descending air

45. Hurricane Scale

46. FORECASTING WEATHER • Two sources of forecasting weather • Data collected from upper atmosphere • Data collected on the Earth’s surface

47. Weather Balloons • Collects a vertical profile of the atmospheres temperature, relative humidity, air pressure, wind speed and direction and transmits the information to a meteorologist on the ground

48. Weather Satellites • Provides visual data of weather systems and helps track weather located in distant locations.

49. Weather RADAR • Locates Fronts, precipitation and severe weather.