1. Unit 4
Weather
about Doppler Radar

2. weather basics the uneven heating of the Earth’s surface
Where does the energy for weather originate?
the uneven
heating
of the Earth’s
surface

5. Heat Transfer in 3 ways:

6. In the US, the general direction that weather systems
weather basics
In the US, the general direction that weather systems
move is toward
the
North and East
FROM the SW

7. RUNOFF INFILTRATION PRECIPITATION CONDENSATION EVAPORATION ABSORPTION
TRANSPIRATION
RUNOFF
ABSORPTION
INFILTRATION

8. dewpoint are measured in
Station Models
Please go to page 13 of the
ESRTs
Temperature and
dewpoint are measured in
degrees _______ 0F

9. .. 76 138 -30\ 55 Cloud Cover Temperature Wind Direction & Speed
Present Weather 55
Dewpoint
Barometric
Trend
Barometric
Pressure

11. Barometric
Pressure
138
ADD a 9 if the number is above “500” or a 10 if the number is below “500” in front to fit on the scale (ranges from to )
10138
Add a decimal between the last two digits mb

12. Trend (last 3 hours) The decimal has been omitted (left out) 30 = 3.0
+ means rising
- means falling

13. Present weather is light rain
Station models info.
Temp
Dew
cloud
Press (mb)
Trend
Wind
Speed
760 F
550 F
100%
1013.8
Falling 3.0 mb NE
15 knots
Present weather is light rain

14. Station Model Practice
Wkst 1 and 2

15. MOISTURE page 5

16. Evaporation Rates
a- Temperature
c- Relative Humidity
b- Surface Area

17. as temperature increases, the rate of evaporation
Direct
Relationship
as temperature increases,
the rate of evaporation
increases

18. as surface area increases, the rate of evaporation
Direct
Relationship
as surface area increases,
the rate of evaporation
increases

19. as the air becomes more saturated, the rate of evaporation
Relative Humidity
The % of moisture in the air
Inverse
Relationship
as the air becomes more saturated,
the rate of evaporation
decreases

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

21. Cloud Formation

22. dewpoint = condensation
Cools to the
dewpoint = condensation
Expands & cools
Warm
Air Rises

23. Clouds are likely to form when:
The air is SATURATED and RISING
The temperature is at the DEWPOINT
Condensation NUCLEI are available

26. As air temperature increases
the air can "hold"
more water

27. lower due to evaporation
Sling Psychrometer
Dry bulb measures
air temperature
Wet bulb temp is
lower due to evaporation

28. 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

29. Relative Humidity vs Air Temperature
Inverse
Relationship
as temp. decreases
RH increases

30. As dew point increases, the amount of moisture in the air

31. dewpoint get closer together, the probability of precipitation
As temperature
and
dewpoint get closer together,
the probability of precipitation
INCREASES

32. Circle the precip. probability

33. probability of precipitation?
Which has the greatest
probability of precipitation?