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
4.
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
6.
7.
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.“
9.
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
11.
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
13.
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
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
18.
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
21.
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
24.
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
27.
28. Ingredients
Moisture, instability, uplift
Life Cycle – lasts about 30 min
Towering Cumulus (strong updrafts)
Mature Cumulus (updrafts and down drafts)
Dissipating Stage (downdrafts)
29.
30.
31.
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)
33.
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