1. The Weather Station Model
Draw a Station Model
Get accompanying notes here

2. 196 19.6 919.6 1019.6 Decoding the Coded Pressure: 960-1040
Insert a decimal point to the left of the last digit
19.6
Put a “9” and a “10” in front of the result
919.6
1019.6
Test the results against the range of normal atmospheric pressures
919.6 is below the range of normal pressures….
REJECTED!
is within the range of normal pressures….
ACCEPTED!
Coded pressure 196= mb
Decode these coded pressures:
1000.2
999.3
1028.0
1000.0
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How to encode pressures

3. Encoding the Pressure
1013.5
Remove the decimal point
10135
Report the last 3 digits
135
Pressure = 135 encoded pressure
Encode these pressures:
327
873
122
001
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Back to Decoding Pressures

4. / means the pressure is currently rising
The Barometric Trend /
+ means “Higher now than it was 3 hours ago”
(- means “Lower now than it was 3 hours ago”)
19 means the pressure has changed by 1.9 mb
/ means the pressure is currently rising
( \ means the pressure is currently falling)
What was the pressure 3 hours ago?
Here?
1017.7
1003.5
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5. Back to the Station Model

6. NE at 25 Knots
E at 5 Knots
SE at 10 Knots
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7. Draw a Station Model for These Conditions:
Temperature= 45F
Dewpoint= 32F
Wind NE at 20 knots
Overcast
Visibility= 1.5 miles
Slight Rain showers
Pressure Now= mb
Pressure 3 hrs. ago= mb
Barometer Falling
Precipitation in last 6 hrs.= .53 in.
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8. Draw the following station model:
Temperature: 94 °F
Barometric Pressure: mb
Visibility: 3 miles
Cloud cover: 1/10
Barometric Pressure Change: +27 and rising
Wind Direction: from the south
Wind Speed: 25 knots
Dew Point Temperature: 62 °F
Precipitation during the last three hours 0.25
Current weather: Light drizzle

9. 1 Interpret the following station model: Temperature Cloud cover
Dew point
Wind direction
Wind speed
Barometric pressure
Barometric trend
8. What was the barometric pressure three hours ago? 1

10. % Relative Humidity Calculations
Step 1: Convert both temperature and dewpoint to degrees Celsius
Step 2: Dry bulb temperature is temperature reading.
Step 3: Subtract dew point in Cº from temperature in Cº . That is difference on table.
Step 4: Intersect #2 and #3 on chart record humidity.