1. Weather Part I Revised 2010 Revised 2010 ©Mark Place, 2009-2010
Revised 2010
Revised 2010

2. In the US, the general direction that weather systems move is toward
weather basics
Where does the energy for weather originate?
the uneven heating
of the Earth’s surface
In the US, the general direction that weather systems move is toward
the northeast

3. dewpoint are measured in Pressure (see next page)
Station Models
Use the ESRT Page 13
Cloud Cover
Temperature .. 76
138
Wind Direction
&
Speed
-30\
Current Weather 55
Dewpoint
Barometric
Trend
Barometric
Pressure
Temperature and
dewpoint are measured in
degrees _______
Pressure (see next page) F

4. Barometric
Pressure
138
Add a decimal between the last two digits
13.8
Add a 9 or 10 in front to fit on the scale
(ranges from to )
If under 500 add a 10
If over 500 add a 9
Pressure =1013.8
Click on for Interactive Station Model Practice

5. Moisture: What Affects Evaporation?
Temperature
As temperature increases, rate of evaporation increases
Direct
Relationship
Surface Area
As surface area increases, rate of evaporation increases
Direct
Relationship
As relative humidity increases, rate of evaporation decreases
Relative Humidity
Indirect
Relationship

6. What natural process
cleans the atmosphere?
precipitation
Rain
Snow
Hail

7. Cloud Formation
Cools to the
dewpoint
Expands
Warm
Air Rises

8. Clouds are likely to form when:
The air is saturated and rising
The temperature is at the dewpoint
Condensation nuclei are available

9. As the Air Temperature Increases, the air can hold more water
Sling Psychrometer
Used to measure RH & Dew point
Dry bulb measures air temperature
Wet bulb temp is lower due to evaporation
Use dry bulb temp. and wet bulb depression to find DP or RH on chart

10. Using the charts on page 12 of the ESRTs, calculate the relative
humidity and dew point using the following information.
Dry Bulb
Wet Bulb
Difference
Dew Point
Relative Humidity (%) 14 10 4 20 5 30 19 18 56 6 60 15 12 58 23 7 55 13 5 9
Dewpoint Chart
RH Chart

11. As temperature increases Relative Humidity decreasesvs
Air Temperature
Indirect
Relationship
Temp.
As temperature increases
Relative Humidity decreases
Amount of moisture in the air RH

12. As dew point increases the amount of moisture in the air
As temperature
and dewpoint get closer together,
the probability of precipitation
INCREASES

13. Temperature versus Dew point
Rain
On your study guide circle the area of the diagram where RAIN would occur.

14. probability of precipitation?
Which has the greatest
probability of precipitation?
Temp.&DP are very close

15. Pressure and Wind
©Mark Place,

16. What instrument is used to measure:
wind speed
air pressure
anemometer
barometer
[ORIGIN from Greek anemos ‘wind’]
[ORIGIN from Greek baros ‘weight’]

17. The direction in which they come from Differences in Pressure
How are winds named?
The direction in which they come from
What causes wind?
Differences in Pressure

18. Which pressure gradient would result in greater wind velocity?

19. measurements using the chart
Convert the following
measurements using the chart
on page 13 of the
ESRTs.
29.73
997
30.18
994

20. Wind blows from areas of
to areas of
high
pressure
low
pressure

21. Draw the relationship between air pressure and air density.

22. This is because the air is Therefore, clouds CANNOT form.
In a high pressure area,
air will (rise, sink)
because the air is
(less, more) dense.
This is because the air is
(cold, warm)
and (rises, sinks).
Therefore, clouds CANNOT form.

23. This is because the air is
In a low pressure area,
air will (rise, sink)
because the air is
(less, more) dense.
This is because the air is
(cold, warm)
and (rises, sinks).
Therefore, clouds are
LIKELY to form.

24. Correctly draw the direction of wind flow
around both a high and a low pressure area
in the NORTHERN HEMISPHERE.

25. counterclockwise wind direction
low pressure
high pressure
warm or cold air
air rising or sinking
clouds or no clouds
clockwise or
counterclockwise wind direction
winds toward or
away from the center
warm
cold
rising
sinking
clouds
no clouds
counter clockwise
clockwise
toward
away

26. H L Sea Breeze (daytime)
On the diagrams below, label which one represents a
land breeze and which represents a sea breeze.
Correctly label on each diagram where the
high and low pressure areas would be found. H L
Warm air
Cool air
Sea Breeze (daytime)

27. Land Breeze (night time)
On the diagrams below, label which one represents a
land breeze and which represents a sea breeze.
Correctly label on each diagram where the
high and low pressure areas would be found.
Warm air H L
Cool air
Land Breeze (night time)