Global air circulation patterns are complicated by the Earth's rotation, tilted axis, and uneven distribution of land masses. These patterns are categorized into three circulation cells: Hadley, Ferrel, and Polar. Jet streams are fast flowing air currents in the upper atmosphere that blow from west to east and vary in location between summer and winter. Köppen classified world climates based on typical temperature and moisture profiles.

3.  Global circulations explain how air and storm
systems move over the earth’s surface
 The circulation patterns are complicated by 3 factors:
 Earth’s rotation
 Tilted axis
 Uneven distribution of land in Northern and Southern
Hemisperes
 This complicated circulation patterns are broken into
3 “cells”:
 Hadley – around equator, blows toward equator
 Ferrel – mid-latitude, blows toward poles
 Polar – around poles, blows easterly

5.  Jet streams are relatively narrow bands of strong
wind in the upper levels of the atmosphere.
 The winds blows from west to east
 Jet streams are the strongest for both the northern
and southern hemisphere winters

8.  The Jet stream follows the sun’s angle in the
sky, southerly in the summer and northerly in the
winter.
 Jet streams are typically wide and not distinct, but
a region where the wind increase toward a core
of strongest wind.
 One way of visualizing this is consider a river.
 The river's current is generally the strongest in the
center with decreasing strength as one approaches the
river's bank. It can be said that jet streams are "rivers
of air.“

10.  The reoccurring "average weather" found in any
particular place
 German climatologist Wladimir Köppen divided the
world's climates into categories based on general
temperature profile related to latitude
 A. Tropical, B. Dry, C. Moist Sub-tropical, D. Moist
Continental, E. Polar, and F. Highlands

12.  Heat waves kill more people in the United States
than all of the other weather related
disasters combined
 Humans perspire to cool themselves, therefore the
higher the humidity, the harder it is for humans to
cool themselves
 Heat index is a function of humidity and temperature
 Remember, these values are in the SHADE
 You can add up to 15°F (8°C) to these values if you
are in direct sunlight

14.  The effect of the wind on people and animals
 As the wind increases, it removes heat from
the body, driving down skin temperature
 inanimate objects will not cool below the actual
air temperature

15. Temperature (°F)
W
i
n
d 40 35 30 25 20 15 10 5 0 -5 -10 -15 -20 -25 -30 -35 -40 -45 -50 -55 -60
(mph
)
0 40 35 30 25 20 15 10 5 0 -5 -10 -15 -20 -25 -30 -35 -40 -45 -50 -55 -60
5 37 31 25 19 13 7 1 -5 -11 -16 -22 -28 -34 -40 -46 -52 -58 -63 -69 -75 -81
10 34 27 21 15 11 3 -4 -10 -16 -22 -28 -35 -41 -47 -53 -59 -66 -72 -78 -84 -90
15 32 25 19 13 6 0 -7 -13 -19 -26 -32 -39 -45 -51 -58 -64 -71 -77 -83 -90 -96
-
20 30 24 17 11 4 -2 -9 -15 -22 -29 -35 -42 -48 -55 -61 -68 -74 -81 -88 -94
101
-
25 29 23 16 9 3 -4 -11 -17 -24 -31 -38 -44 -51 -58 -64 -71 -78 -84 -91 -98
104
- -
30 28 22 15 8 1 -6 -12 -19 -26 -33 -39 -46 -53 -60 -67 -73 -80 -87 -94
101 107
- -
35 28 21 14 7 0 -7 -14 -21 -27 -34 -41 -48 -55 -62 -69 -76 -83 -89 -96
103 110
- -
40 27 20 13 6 -1 -8 -15 -22 -29 -36 -43 -50 -57 -64 -71 -78 -84 -91 -98
105 112
- - -
45 26 19 12 5 -2 -9 -16 -23 -30 -37 -44 -51 -58 -65 -72 -79 -86 -93
100 107 114
- - -
50 26 19 12 4 -3 -10 -17 -24 -31 -38 -45 -52 -60 -67 -74 -81 -88 -95
102 109 116

16.  All aspects of meteorology are based upon a
world-wide 24-hour clock called Zulu time
 more commonly called Universal Time
Coordinate
 With the 360° daily rotation of the earth, the sun
is moving 15° each hour which leads to the
formation of 24 time zones
 Based on the time in Greenwich, England.
 00Z (midnight zulu) is 6 pm Central Standard

17.  Clouds form when air is cooled to its dewpoint
 the temperature the air reaches saturation
 As air rises, it expands due to less pressure, and
cools do to expansion
 Called the Adiabatic Process
 The rate of this cooling and expanding with elevation
is called lapse rate
 the dry lapse rate is a constant
 for each 1000 feet increase in elevation, the air temperature
will decrease 5.4°F

19.  Cirro form – high level clouds composed mostly of
ice crystals, denote fair weather
 Nimbo form – mid-level clouds that are very heavy
with moisture and bring steady rain
 Cumulo form – fluffy midlevel clouds that have a flat
base and are very tall
 Strato form – low level clouds that form a blanket
over the sky and bring dizzily weather

20.  Air in motion
 A wind vane measures the wind direction
 An anemometer measures the wind speed
 Isobars on a weather map denote areas of equal
pressure
 The closer the isobars, the greater the pressure gradient
 Wind speed is directly proportional to pressure
gradient
 Wind speed and direction are also impacted by the
coriolis force – the earth’s rotation

22.  Winds spiral out of high pressure regions and
into low pressure regions because of friction.

23.  Fronts are the boundaries between two air masses
 The front is classified by what type of air is moving
into the region (warm/cold)
 Warm fronts typically have a gentle slope so the air
rising along the frontal surface is gradual
 stratiform cloudiness and precipitation along and to the
north of the front
 The slope of cold fronts are more steep and air is
forced upward more abruptly
 narrow band of showers and thunderstorms along or just
ahead of the front

25.  Needs ingredients to create
 A source of moisture
 Typically a large body of water like oceans
 Lifting of moist air must occur
 Mountains, pressure gradients, frontal boundaries
 Ice crystals or water droplets need to grow
large enough to fall
 Collision and coalescence or ice crystal method

26.  Rain – liquid water droplets
 Snow – Crystallized frozen water
 Sleet – frozen water droplets
 Freezing Rain – Water droplets that freeze when
they land on objects
 Hail – Larger balls of ice that have formed from
repeated lifting and falling through the atmosphere
adding layers of ice each time

28.  Ingredients
 Moisture, instability, uplift
 Life Cycle – lasts about 30 min
 Towering Cumulus (strong updrafts)
 Mature Cumulus (updrafts and down drafts)
 Dissipating Stage (downdrafts)

32.  Tornadoes come from super cells with strong
wind sheers.
 The greatest chance for tornado comes from
the mesocyclone area.
 Enhanced F-Scale:
 EF0 (65-85 mph) – EF5
(over 200 mph)

34.  Giant spark of static electricity
 Largely a mystery to scientists
 1 billion volts, 300,000 amps, and 10 miles away
 Thunder is the acoustic shock wave resulting from
the extreme heat generated by a lightning flash
 For every second between the flash of lightning and
the clap of thunder, you can estimate 1 mile until the
storm is directly over you

35.  Stands for RAdio Detection And Ranging
 WSR-88D
 Weather Surveillance Radar - 1988 Doppler
 Gives the ability to detect motion
 Bounces radio waves off of water droplets in
clouds.
 The larger or denser the droplets, the stronger the
reflected signal, and the more severe the storm.

36. Cloud Types
Temperature
Pressure in
mb (999.8)
Visibility (mi)
Current
weather Change in
pressure (mb)
Wind Speed
& Direction
Cloud Types
Cloud Types
Cloud ceiling