2. Much information is needed to interpret what is happening with the atmosphere.
Need to condense this information in a small space
Need to show the geographic characteristics of this data
Weather maps can both display this data
and summarize the patterns

3. Allows the data to be plotted in a condensed and usable format
Station Model
Allows the data to be plotted in a condensed and usable format

4. Location of the station on the map.
The name of the location or airport abbreviation might be given nearby.

5. Temperature information in degrees Fahrenheit.

6. Dew Point Temperature in degrees Fahrenheit.
dewpt

7. A staff is rotated around the station.
Wind direction
A staff is rotated around the station.
Temp
dewpt
Remember, winds are identified as the direction FROM which they come. This would be a west northwest wind or about 290º.

8. Attached to the staff are symbols for speed.
Wind Speed
Attached to the staff are symbols for speed.
Temp
dewpt

9. The coding for the wind speed symbols can be generalized as:
half staff about 5 knots
note, it is not on the end of the wind direction staff
full staff about 10 knots
these are additive for the total amounts
three full staffs=30 knots

10. Current Barometric Pressure
Temp
dewpt
pressure

11. Barometric Pressure is VERY important!
average barometric pressure at sea level is mb.
current barometric pressure is reported to the nearest TENTH
BUT, they don’t want to waste space

12. average barometric pressure at sea level is 1013.25 mb.
barometric pressure varies around this value
+ about 30 = 1043
somewhat higher
1013.3
somewhat lower
- about 30 = 983

13. average barometric pressure at sea level is 1013.25 mb.
barometric pressure varies around this value
they do not PRINT the beginning number or numbers
1013.3 x
133
they, also, do not PRINT the decimal point, but report to the nearest TENTH

14. Which would make the value most realistic?
From the three numbers, you must INTERPRET whether the preceding value is 10 or 9
Which would make the value most realistic?

15. and then consider which, a 10 or a 9
add the decimal point
and then consider which, a 10 or a 9
places the value NEAREST to the average pressure of
mb.

16. (1013.3)
What is the pressure?
084
08.4
1008.4
962
96.2
996.2
281
28.1
1028.1
987.5
875
87.5
322
32.2
1032.2

17. So, more information may be given and must be coded.
Not only is the pressure itself important, but so is the way the pressure has been changing.
So, more information may be given and must be coded.

18. How has the barometer been changing?
Temp
dewpt
pressure
trend
+ it is higher now than in the past
- it is lower now than in the past

19. How much the pressure has changed
Temp
dewpt
pressure
trend
change
the amount of change in the past three hours
again, reported in TENTHS without the decimal

20. What has the pressure been doing? Shown diagrammatically
Temp
dewpt
pressure
trend
change
shown

21. graphic depiction of percentage of the sky covered by clouds
Total amount of cloud
Temp
dewpt
pressure
trend
change
shown
graphic depiction of percentage of the sky covered by clouds

22. about 60%
no clouds
about 10%
about 75%
about 25%
about 80%
completely overcast
about 40%
sky obscured
about 50%

23. Symbol positions to identify the cloud types
Temp
dewpt
pressure
trend
change
shown
low clouds
middle clouds
high clouds
Cloud types tell much about the weather conditions. The cloud types are identified by symbols, and classed as low, middle, and high clouds.

24. How much of the sky is covered by low and middle cloud cover?
Temp
dewpt
pressure
trend
change
shown
low clouds
middle clouds
high clouds
low or middle cloud cover
What amount, in tenths, of the sky is covered by low or middle clouds. This is a coded number with the percentage close to the printed number.

25. What is the present weather?
Temp
dewpt
pressure
trend
change
shown
low clouds
middle clouds
high clouds
low or middle cloud cover
The current weather is very important.
A detailed set of symbols provides weather descriptions.

26. , * . Samples of present weather symbols. rain fog snow haze
slight rain showers ,
thunderstorm
drizzle .
ice or snow pellets
lightning
cloud development not observed

27. 100 different symbols provide details about the PRESENT WEATHER.

28. The visibility is especially important for pilots.
Temp
dewpt
pressure
trend
change
shown
low clouds
middle clouds
high clouds
visibility
low or middle cloud cover
Visibility is given in miles and fractions

29. The past weather uses symbols.
Temp
dewpt
pressure
trend
change
shown
low clouds
middle clouds
high clouds
visibility
low or middle cloud cover
PAST , *

30. Time precipitation began or ended
Temp
dewpt
pressure
trend
change
shown
low clouds
middle clouds
high clouds
visibility
low or middle cloud cover
PAST
when
Coded for how many hours ago the precipitation began or ended. Again, the code is close to the number of hours.

31. The amount of precipitation
Temp
dewpt
pressure
trend
change
shown
low clouds
middle clouds
high clouds
visibility
low or middle cloud cover
PAST
when
base
amount
Amount of precipitation is plotted in inches to the nearest hundredth of an inch.